STATE OF MONTANA

   Thomas L. Judge, Governor

                                                  December 1Q73
BUREAU OF MINES AND GEOLOGY

   S. L. Groff, Dkector
  QUALITY AND RESERVES OF STRIPPABLE COAL,

  SELECTED DEPOSITS, SOUTHEASTERN  MONTANA
                             by
                  Robert E. Matson and John W. Blumer
                  Montana Bureau of Mines and Geology
                        Analytical Data by
                        Laurence A. Wegelin

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                STATE OF MONTANA
           BUREAU OF MINES AND GEOLOGY
                 S. L. Groff, Director
                   BULLETIN 91
 QUALITY AND RESERVES OF STRIPPABLE COAL,

              SELECTED DEPOSITS,

           SOUTHEASTERN MONTANA
                       by

           Robert E. Matson and John W. Blumer

                 Analytical Data by

                 Laurence A. Wegelin
MONTANA COLLEGE OF MINERAL SCIENCE AND TECHNOLOGY
                  Butte, Montana
                      1974

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                                         Distributed by

                               Montana Bureau of Mines and Geology

                                     Room 203-B, Main Hall

                         Montana College of Mineral Science and Technology

                                     Butte, Montana 59701
Editors-Ralph H. King, Kimberly Bawden
Chief Draftsman-Roger Holmes
Composer Typist-Eleanor Herndon

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                                   CONTENTS

                                                                           Page
Abstract	       	      1
Introduction  ......        ......                    1
   Background for study     ...       	          .1
   Purpose and scope   .  .     	     .     .        .         2
   Location and extent of area	        .     ...           .      2
   Field work	     .     .     .                .2
   Field methods	        ...    4
   Previous geologic work .       .      ....        ....        ...    4
   Land ownership         .  .          .     .      .     ....     .     .4
Geography ....                                          .              6
   Surface features and land use .                     .          ...            6
   Population .            .    .   .     .        .     	     •   •      6
   Transportation       ...     ...     ....     .      .        .      6
   Climate            .....           .                           6
   Water supply            	     .             .                    7
Stratigraphy   .            .            ..........          .7
   Fort Union Formation .  .                              ....      7
     Tongue River Member                                    .     ....    8
     Lebo Member                 ...                        .  .            8
     Tulloch Member    ...        .                  ....    8
   Wasatch Formation  ...                  ....             .9
Geologic structure  .                ....                  .....    9
Coal                                   	        .   .         9
   Coal quantity                 .   .                  ....        .         9
   Burning of the coal          ...                     .             ...    9
   Coal quality                     .             .   .          	13
   Coal beds   .                       ....                ...   13
   Reserve estimates.                     ...             .     .        .18
Strippable coal deposits  .               ...          .     .           18
   Decker area.                            ...                  ...   18
   Kirby coal deposit   .          .             .   .             ....   31
   Canyon Creek coal deposit             ...             ....      .     37
   Bimey coal deposit                       .  .             .   .           .42
   Poker Jim Lookout coal deposit ....                .   .             46
   Hanging Woman Creek coal deposit.          .                ....   49
   West Moorhead coal deposit       .                       .   .                57
   Poker Jim Creek-O'Dell Creek coal deposit     .                        ...   62
   Otter Creek coal deposit               ...                   ...     66
   Ashland coal deposit                ...               .                   71
   Colstrip coal deposit....             .                ....   76
   Pumpkin Creek coal deposit               .                                  82
   Foster Creek coal deposit     .                  .                     .84
   Broadus coal deposit                  .   .                  .   .             89
   East Moorhead coal deposit          ...               .           92
   Diamond Butte, Goodspeed Butte. and Fire Gulch coal deposit      .             95
   Sweeney Creek-Snyder Creek coal deposit        .   .               .          101
   Yager Butte coal deposit  .  .          ...             .        .      .    103
   Sonnette and Threemile Buttes coal deposit                    .   .            107
   Home Creek Butte coal deposit               .                .             .114
   Little Pumpkin Creek coal deposit     .                                      115
   Sand Creek coal deposit           ...           .                         117

                                         iii

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                            CONTENTS (continued)

                                                                        Page
   Beaver Creek-Liscom Creek coal deposit  ...              .        .       119
   Greenleaf Creek-Miller Creek coal deposit.        .  .             .       .123
   Pine Hills coal deposit         ...                                126
   Knowlton coal deposit                        .               ...     129
References .               .            .                    •               134

                               ILLUSTRATIONS

Plate
   Index to plates          .            ...                           Inbox
   1. Decker                                                 ...     Inbox
   2. Deer Creek.  .            .......                      .In box
   3. Roland .       .                 .                            .     .  Inbox
   4. Squirrel Creek .                         .                   .In box
   5. Kirby.          .  .               .        .            .             .  Inbox
     A. Anderson and Wall     .        .       .            ...          Inbox
     B. Dietz.              .        .       ....       .     .     In box
     C. Canyon      .     .               .  .            .          .In box
   6. Canyon Creek.          .             .                 .          .In box
     A. Wall      .                  .                              -     .  Inbox
     B. Canyon                                    ....     In box
   7. Birney                                                  .  .          Inbox
   8. Poker Jim Lookout .                                      .In box
   9. Hanging Woman Creek ...                        .     Inbox
     A. Anderson                 .                                        In box
     B. Dietz .                                                 .In box
  10. West Moorhead                            .                           In box
     A. Anderson                                                    .In box
     B. Dietz.                                ...          In box
     C. Canyon   .   .                                ...       Inbox
  11. Poker Jim Creek-O'Dell Creek             .            .     .            Inbox
     A. South half                     .                  .     .            Inbox
     B. North half                                                        In box
  12. Otter Creek.                                        .                 Inbox
  13. Ashland .            .                                     .In box
     A. Knobloch  .                                                       In box
     B. A, C, and Sawyer.       .                         .     ....  In box
  14. Colstrip                                                   .     .     Inbox
  15. Pumpkin Creek   .                         ...       Inbox
  16. Foster Creek                         .                                Inbox
     A. Knobloch                      .                       .            In box
     B. Terret   .  .        .                    .            .               In box
     C. Flowers-Goodale                   .                      .        .  In box
  17. Broadus .              .                       .                      In box
  18. East Moorhead                              .              ..          Inbox
  19. Diamond Butte                                                       In box
  20. Goodspeed Butte .                                             .In box
  21. Fire Creek           .                           .                    Inbox
  22. Sweeney Creek-Snyder Creek.                    .          .       .     Inbox
  23. Yager Butte.                                   .          .       .     Inbox
     A. Elk and Dunning .                                                  In box
     B. Cook and Wall.                                .                    In box

                                       iv

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                          ILLUSTRATIONS (continued)

Hate
  24. Threemile Buttes ...             .                        .             In box
  25. Sonnette      	       ...           .               .  Inbox
     A. Pawnee     .  .           .                     .        ....        Inbox
     B. Cook....        ...                        .     .        In box
  26. Home Creek Butte   ....                        In box
  27. Little Pumpkin Creek     .                .           .          -       .Inbox
  28. Sand Creek......                          .          In box
  29. Beaver Creek-Liscom Creek                ...          .                Inbox
  30. Greenleaf Creek-Miller Creek .        .                             .In box
  31. Pine Hills        .                     .  .                   .             Inbox
  32. Knowlton       .   .                     .           	Inbox
     A. South half         .               ...                  .   .     Inbox
     B. North half            .             .                                  In box
  33. Cross sections  ....                               .In box
  34. Cross sections  .             .....             .In box

Figure                                                                        Page
   1. Index map showing area discussed in this report.           .  .                  3
   2. Index map showing areas of previous coal studies     	               5
   3. Structure contour map of Montana portion of Powder River Basin        .  .    10
   4. Columnar sections showing relationship of coal beds in northern part of area .    12

                                      TABLES

Table
   1. Coal reserves, acreage,  and tons per acre, selected strippable coal deposits         11
Decker area
   2. Coal reserves, overburden, overburden ratio, acres, and tons per acre in
        Decker, Deer Creek, Roland, and Squirrel Creek                            19
   3. Proximate analysis, forms of sulfur, heating value                               20
   4. Trace-element analysis                 .          .                         22
   5. Trace-element  analysis, ppm coal, ppm ash  .           .                       23
   6. Major ash constituents                       .             .                  24
Deer Creek
   7. Proximate analysis, forms of sulfur, heating value     .                         25
   8. Major ash constituents       .             ...                    26
Roland
   9. Proximate analysis, forms of sulfur, heating value     .                         27
  10. Major ash constituents               ...                         28
Squirrel Creek
  11. Proximate analysis, forms of sulfur, heating value                  .       .    29
  12. Major ash constituents               .             .                         30
Kirby
  13. Reserves, overburden, overburden ratio, acres, and tons per acre                  32
  14. Proximate analysis, forms of sulfur, heating value     .                         34
  15. Major ash constituents                                                      36
Canyon Creek
  16. Reserves, overburden, overburden ratio, acres, and tons per acre             .    37
  17. Proximate analysis, forms of sulfur, heating value           .                    38
  18. Major ash constituents ...                                       41
Birney
  19. Reserves, overburden, overburden ratio, acres, and tons per acre                  42

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                                 TABLES (continued)

Table                                                                          Page
Birney (continued)
  20. Proximate analysis, forms of sulfur, heating value        	            43
  21. Major ash constituents    .        	        .44
Poker Jim Lookout
  22. Reserves, overburden, overburden ratio, acres, and tons per acre  .   .     .  .    46
  23. Proximate analysis, forms of sulfur, heating value	47
  24. Major ash constituents    .        .          	        .48
Hanging Woman Creek
  25. Reserves, overburden, overburden ratio, acres, and tons per acre             .    49
  26. Proximate analysis, forms of sulfur, heating value     ...        .        .50
  27. Major ash constituents       .                .....            54
West Moorhead
  28. Reserves, overburden, overburden ratio, acres, and tons per acre  ...      58
  29. Proximate analysis, forms of sulfur, heating value  .          	59
  30. Proximate analysis, ultimate analysis, heating value           .  .               60
  31. Grindability, forms of sulfur, fusibility of ash °F        .        ....      60
  32. Major ash constituents ...        .     	     ....     .61
Poker Jim Creek-O'Dell Creek
  33. Reserves, overburden, overburden ratio, acres, and tons per acre        .  .      63
  34. Proximate analysis, forms of sulfur, heating value	     .   .         64
  35. Major ash constituents       .....                   .        .65
Otter Creek
  36. Reserves, overburden, overburden ratio, acres, and tons per acre     .   .     .67
  37. Proximate analysis, forms of sulfur, heating value  .  .      ....            68
  38. Major ash constituents .          	                            70
Ashland
  39. Reserves, overburden, overburden ratio, acres, and tons per acre  .               71
  40. Proximate analysis, forms of sulfur, heating value  ....             .      72
  41. Major ash constituents .        ......             .  .    74
Colstrip
  42. Reserves, overburden, overburden ratio, acres, and tons per acre     .   .     .76
  43. Proximate analysis, ultimate analysis, heating value           .          .      78
  44. Forms of sulfur and fusibility of ash °F          	               80
Pumpkin Creek
  45. Reserves, overburden, overburden ratio, acres, and tons per acre  ...         82
  46. Proximate analysis, ultimate analysis, heating value, fusibility of ash °F   .  .    83
Foster Creek
  47. Reserves, overburden, overburden ratio, acres, and tons per acre  .           .    85
  48. Proximate analysis, ultimate analysis, heating value.     .              .  .      86
  49. Forms of sulfur, fusibility of ash °F.  .       ...                 .  .      87
  50. Major ash constituents    .                         ...          .  .    88
Broadus
  51.  Reserves, overburden, overburden ratio, acres, and tons per acre  .   .            90
  52. Proximate analysis, ultimate analysis, heating value           .     .   .     .    91
  53. Major ash constituents and fusibility of ash °F                      ....    91
East Moorhead
  54.  Reserves, overburden, overburden ratio, acres, and tons per acre          .  .    92
  55. Proximate analysis, forms of sulfur, heating value        .                       93
  56.  Major ash constituents                  .  .                         .  .      94
Diamond Butte
  57.  Reserves, overburden, overburden ratio, acres, and tons per acre
         (Diamond Butte, Goodspeed Butte, and Fire Gulch)  .   .             .95

                                           vi

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                                TABLES (continued)

Table                                                                         Page
Diamond Butte (continued)
  58. Proximate analysis, forms of sulfur, heating value	             .96
  59. Major ash constituents .     ......                .   .     .   .     .97
Goodspeed Butte
  60. Proximate analysis, forms of sulfur, heating value  .  .        ....     .98
  61. Major ash constituents .     .           .          	98
Fire Gulch
  62. Proximate analysis, forms of sulfur, heating value	        .  .   99
  63. Major ash constituents ....     	                ...   99
Sweeney Creek-Snyder Creek
  64. Reserves, overburden, overburden ratio, acres, and tons per acre  .     .     .101
  65. Proximate analysis, ultimate analysis, forms of sulfur, heating value  .   .   .  .102
  66. Major ash constituents and fusibility of ash °F  ...          .  .      .     102
Yager Butte
  67. Reserves, overburden, overburden ratio, acres, and tons per acre     .   .     .103
  68. Proximate analysis, forms of sulfur, heating value  .  .                        104
  69. Major ash constituents            .        .  .           .     .             106
Sonnette
  70. Reserves, overburden, overburden ratio, acres, and tons per acre
        (Sonnette and Threemile Buttes)	           .   .     .      .109
  71. Proximate analysis, forms of sulfur, heating value          ....           110
  72. Major ash constituents               ....                              Ill
Threemile Buttes
  73. Proximate analysis, forms of sulfur, heating value  .  .     .   .        ...   112
  74. Major ash constituents ...                           .     .             113
Home Creek
  75. Reserves, overburden, overburden ratio, acres, and tons per acre     .           114
Little Pumpkin Creek
  76. Reserves, overburden, overburden ratio, acres, and tons per acre                115
Sand Creek
  77. Reserves, overburden, overburden ratio, acres, and tons per acre                117
  78. Proximate analysis, ultimate analysis, heating value                           118
  79. Major ash constituents and fusibility of ash °F     .             ...     .118
Beaver Creek-Liscom Creek
  80. Reserves, overburden, overburden ratio, acres, and tons per acre                120
  81. Proximate analysis, forms of sulfur, heating value    .          ...     .121
  82. Major ash constituents       .                   .        .....   122
Greenleaf Creek-Miller Creek
  83. Reserves, overburden, overburden ratio, acres, and tons per acre  ....     123
  84. Proximate analysis, forms of sulfur, heating value	        124
  85. Major ash constituents .  .              .        .  .        ...        .125
Pine Hills
  86. Reserves, overburden, overburden ratio, acres, and tons per acre	127
  87. Proximate analysis, ultimate analysis, heating value, forms of sulfur             128
  88. Major ash constituents and fusibility of ash °F          .      .                128
Knowlton
  89. Reserves, overburden, overburden ratio, acres, and tons per acre     .   .        129
  90. Proximate analysis, forms of sulfur, heating value  ...      .           .  .   130
  91. Major ash constituents               .             .                        132
                                           vu

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                           QUALITY AND RESERVES OF STRIPPABLE COAL,

                                             SELECTED DEPOSITS,

                                         SOUTHEASTERN MONTANA


                                      By Robert E. Matson and John W. Blumer



                                                    ABSTRACT
                     Quality and quantity of strippable subbituminous and lignite coal in 32 deposits are de-
                  scribed, and coal distribution is shown on 46 plates. All of the coal is classified as low in sulfur
                  except the Sweeney Creek-Snyder Creek coal deposit; its reported sulfur content exceeds 1% in
                  four core samples. Total strippable reserves are 32 billion tons on 770,000 acres.

                     Proximate analyses, forms of sulfur, calorific values, and major ash constituents of the coal
                  samples are tabulated.

                     The report includes the results of Montana Bureau of Mines and Geology projects in coopera-
                  tion with Burlington Northern,  Inc., and with the Office of Fuel Resources, Environmental
                  Protection Agency, supported by special appropriations by the Legislature.
                                                 INTRODUCTION
             BACKGROUND FOR STUDY
   In recent years, concern about the environment has
resulted in legislative restrictions on SOa emissions from
fore seeking low-sulfur fuel to help them to comply with
these regulations.

   In the late sixties, the National Air Pollution Control
coal-fired power plants. The power companies are there-      Administration, U.S. Department of Health, Education,
   Dr. Albert P. Talboys, in 1969 the acting Chief of the Office
of Fuel Resources, National Air Pollution Control Administration,
U.S. Department of Health, Education, and Welfare (now the Air
Pollution  Control  Office  of  the  Environmental  Protection
Agency), encouraged and supported the major project. The assis-
tance and cooperation of Dr. S.L. Groff, State Geologist and Di-
rector of the Montana Bureau of Mines and Geology (then Chief
of the Ground Water and Mineral Fuels Division of the Montana
Bureau of Mines and Geology), in obtaining this grant is also appre-
ciated. Charles D. Yaffe, former Director, Don R. Goodwin, for-
mer Acting Director, and Robert L. Ajax, Chief of the Division of
Control  Agency Development,  facilitated administration of this
project. Russel C. Flegal and Robert M. Jimeson, Physical Science
Administrators, aided in the completion of this project. Frederick
W. Lawrence, Chief of the Washington Liaison Staff of the En-
vironmental Protection Agency, provided support for the project.
Henry C. Steed, Chief of the  Grants Operation Branch of the En-
vironmental Protection  Agency,  expedited fourth year project
funds.

   Several Federal agencies cooperated with the Bureau on this
project. Elmer M. Schell, Area Geologist, Northern Rocky Moun-
tain area, Mineral  Classification Branch of the U.S. Geological
Survey in Casper,  Wyoming, took an active interest in the field
program as it  was executed, and he reviewed the report previous
to publication. The Bureau of Land Management provided special
use  permits for drilling test holes on federally owned coal lands,
and the  Forest Service also provided such permits on the Custer
National Forest within the mapped area. Both the Bureau of Land
Management and the  U.S. Forest   ervice also provided colored
photos and high altitude infrared  photographs where available.
The Pittsburgh Energy Research Center, under Forest E. Walker
and Roy S. Abemathy, provided control samples and advice on
analytical techniques.

   George Nugent and John R.  Ratchye of Rosebud Coal Sales
Company provided data useful in evaluation of the Decker and
Deer Creek coal deposits. Graham  R. Curtis of Gulf Mineral Re-
sources helped to name and correlate the coal beds and provided
data on the Kirby coal deposit. Ernest Thurlow, Barney Binon,
Loren Williams, and Peter Mattson of Burlington Northern, Inc.,
provided data for this report. Loren Williams also compiled sev-
eral of the maps in this report from field data.

   Over the four-year period, many student assistants, graduate
assistants, and staff members of the Montana Bureau of Mines and
Geology worked on various aspects of the project. Wayne Van
Voast, associated with the  project during 1969 and 1970, con-
ducted the field program in the latter part of the 1969 field sea-
son and the 1970 field season. Others who worked on the project
are  Eldon Woods,  draftsman for the Bureau, Gardar G.  Danl,
Michael R. Garverich, Charles Speake, Jr., Melvin Granberg, Leon-
ard  Maki, Van Heare, and Robert Lambeth. Recognition is due
the  staff involved in the compilation of the final report, includ-
ing  Mrs.  Mayme Domme,  Mrs. Dorothy  Ratcliff, Miss  Sheila
McCarthy, Mrs. Carol Blankenship, and Miss Vonnie Lave)'<-.

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                                STRIPPABLE COAL, SOUTHEASTERN MONTANA
and Welfare (now the Air Pollution Control Office of the
Environmental Protection Agency) recognized the need
for information about the quality and quantity of low-
sulfur western coal, as well as about economic conditions
that would permit use of this coal to assist in combating
air  pollution. The  Air Pollution Control Office  of the
Environmental Protection Agency began efforts to evalu-
ate western coals in cooperation with agencies in various
states, including the Montana Bureau of Mines and Geol-
ogy, and with other Federal agencies.

   The Fort Union coal region of eastern Montana was
of interest because of the known reserves of low-sulfur
subbituminous and lignite coal minable by surface meth-
ods. Characteristics of the topography and the thickness
of the coal beds make possible the mining of large quan-
tities of coal from relatively small, compact areas, which
facilitates reclamation. Coal beds 25 to 60 feet thick are
not uncommon,  and in the Decker area the coal in a
single bed reaches a thickness of 80 feet.

   Production of coal from thick seams by strip mining
is much less costly and much less hazardous for the work-
men than  production by underground  operations. Fur-
thermore,  90% of the coal can be recovered by surface
mining, whereas only 50 to 55% can be recovered by
underground methods.

   Dr. Albert P. Talboys (then acting chief of the Office
of Fuel Resources for the National Air Pollution Control
Administration) and Dr.  S.L. Groff, State Geologist and
Director of the Montana Bureau of Mines and Geology,
began preliminary planning early in 1969. In June 1969,
the Office of Air Pollution Control of the Environmental
Protection Agency approved a matching grant (Grant No.
69A-2901D), which was followed by Grant No. 70 (70B-
2901D) for the second, third, and fourth years. The tide
of the project proposal was "Field Evaluation of Eastern
Montana's Low-Sulfur, Low-Air-Pollutant Lignite and
Subbituminous Coal Reserves." The funds granted by the
Environmental Protection Agency were matched on an
almost equal basis by the Montana Bureau of Mines and
Geology.

              PURPOSE AND SCOPE

   The purpose of this project was to acquire qualitative
and quantitative  information on selected strippable de-
posits of subbituminous and lignite coal in southeastern
Montana. That area was chosen because it was known to
contain the highest-ranked coal of the Fort Union For-
mation, whereas  most of the coal in the rest of eastern
Montana ranked  as lignite. Higher-ranked coal  was pre-
ferred to lignite because of the expectation that much of
the coal would be shipped long distances as a substitute
for coal of higher sulfur content then being mined in the
midwestern and  eastern  coal areas. Subbituminous coal
has higher Btu (British  thermal unit) content and  less
moisture than lignite. On the "as received" basis, the per-
centage of sulfur is about the same, but when sulfur con-
tent per million Btu  is computed, the subbituminous
coals have a distinct advantage. Transportation cost on a
"cents per million Btu"  basis also  favors subbituminous
coal over lignite.

   Portions of Big Horn, Rosebud, Powder River,  and
Custer Counties were mapped to determine the strippable
coal in various coal beds in the Tongue River Member of
the Fort Union Formation. The report describes the re-
sults of this four-year  project and  also some work com-
pleted earlier.

   Some of the work done prior to the start of the EPA
project was done by the Montana Bureau of Mines  and
Geology in cooperation with Burlington Northern, Inc.,
beginning  in 1966, when the Foster Creek coal field  was
evaluated  (Gilmour and Williams, 1969). In 1967  and
1968, cooperative projects continued, and the Broadus,
Sand Creek, Sweeney Creek-Snyder Creek, and Pine Hills
coal deposits were mapped. Also during 1968, the Bureau
completed most of the field work on the West Moorhead
coal field  (Matson,  1971), the results of which are in-
cluded in  the  present  publication.  The Colstrip  and
Pumpkin Creek areas,  previously mapped by Burlington
Northern, are also included.

   All  available private-company drill-hole information
was used in the same manner as project field data. Much
information about  the Decker and Kirby coal fields was
provided  by  the Rosebud Coal Sales  Company, Gulf
Mineral Resources Company, and Pat McDonough. Where
available, oil-well electronic logs greatly aided in the  cor-
relation of the coal beds.

        LOCATION AND EXTENT OF AREA

   The area described  in this report includes parts of Big
Horn,  Rosebud, Powder River,  and  Custer Counties,
Montana (Fig. 1). The Crow  Indian Reservation and the
Northern  Cheyenne Indian Reservation were excluded
from this  study. The Sarrpy Creek area was also excluded
because of the large amount  of coal under Indian tribal
ownership.

                   FIELD WORK

   Most of the field work for the major project was done
during the summers of 1969, 1970, 1971,  and 1972.

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                       LOCATION AND EXTENT OF AREA
l

              MONTANA
                 	-^HAROIN     I
                                      !  CHEYENNE    ;
                                      '   INDIAN       ,
                                          RESERVATION'
                   CROW

                      INDIAN

                        RESERVATION
                     Figure 1.-Index map showing area discussed in this report.

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                                 STRIPPABLE COAL, SOUTHEASTERN MONTANA
During these periods, 284 project holes were drilled and
3,272 feet of coal core obtained. Of these totals, 74 holes
were drilled in 1969, and 1317 feet  of coal core ob-
tained; 105 holes were drilled in 1970, and 1,244 feet of
core obtained; 75 holes were drilled in 1971, and 692
feet of core obtained; and 10 holes were drilled in 1972,
and 19 feet of core obtained. Most of  the field work in
1972 consisted of surface mapping of coal outcrops, burn
lines, and geologic structures in the Decker-Birney area.
Small amounts of additional drilling during the late fall
and winter  of 1972 and early 1973 yielded information
needed for  completion of the overburden maps within
that area. Additional drill data and core analyses useful
to this project were obtained from a related project spon-
sored by the Mineral Classification Branch of the U.S.
Geological Survey and incorporated in this report.
                 FIELD METHODS
   The field method utilized in this project was patterned
after that developed by Burlington Northern, Inc., (Car-
michael, 1967) and was modified to fit varying condi-
tions. As the method was originally developed to evaluate
area's where  adequate topographic maps were not avail-
able, it included the setting of temporary bench marks by
leveling and the measuring of topographic configurations
by  altimeter surveys. Concurrently  with the  altimeter
survey, coal  outcrops,  clinker,  and  burn lines were
mapped; holes were drilled to permit measurement of the
thickness of the coal and to obtain core samples for analy-
sis  of coal quality. Areas including Colstrip  (PI. 14),
Pumpkin  Creek (PI. 15), Broadus (PI. 17), Sand Creek
(PI. 28), Sweeney Creek-Snyder Creek (PI. 22), Pine Hills
(PI. 31), and West Moorhead (PI. 10A, B, and C) were
mapped by this method.


   Our modifications of the Burlington Northern field
method included use of an American Paulin microbaro-
graph for recording variations in air pressure and use of a
computer for correcting altimeter elevations for changes
in temperature and pressure. In other areas, topographic
maps on a scale of 1:24,000 prepared by the U.S. Geo-
logical Survey  Topographic Mapping Branch were avail-
able. In these areas, the principal field work consisted of
determination  of drill-hole locations and access, surface
mapping, and drilling and coring. During the drilling oper-
ation, a driller's log showing the lithologic sequence was
compiled, lithologic samples were obtained, and coal beds
were  cored for analysis where possible. After  the com-
pletion of each drill hole, geophysical logs showing resis-
tivity, spontaneous potential, and natural gamma were
obtained, except in 1969 when the logging unit was not
available. Collar altitude at each drill hole was measured
by aneroid altimeter from the nearest point of known al-
titude and is thought to be accurate within 5 feet. Almost
all project drill holes were plotted and all coal outcrops,
clinker, and burn lines were mapped on 7^-minute topo-
graphic quadrangle maps where  available or on  aerial
photos  if topographic maps were not available.  Cores
taken during the drilling were inspected, measured, and
wrapped in  cellophane  for  delivery to the Montana
Bureau of Mines and Geology analytical laboratory.
            PREVIOUS GEOLOGIC WORK


   All of the area included in this report had been mapped
previously by the US. Geological Survey, and parts had
been  mapped by the Montana Bureau of Mines and
Geology (Fig. 2). The US. Bureau of Mines published a
report (Ayler, Smith,  and Deutman, 1969) on various
strippable coal deposits in Montana. A recent map of the
Decker  quadrangle (Law and Grazis, 1972)  has been
placed on open file. A two-part report entitled "Prelimi-
nary Summary Report of the Strippable Low-Sulfur Coals
of Southeastern Montana" (Part 1) by Robert E. Matson
and Wayne  A. Van  Voast and  "Markets for Montana
Coal" (Part 2) by Cameron Engineers, was prepared and
placed on open file in 1970.


                 LAND OWNERSHIP

   The largest coal owner in the area discussed in this re-
port is  the  Federal Government. Burlington Northern,
Inc., is the next-largest coal owner, as a result of the land
grant  of 1864 that gave the  railroad all available  odd-
numbered sections in an area 60 miles on each side of
railroad right-of-way. Within that large area, the principal
coal ownership is about equally divided between the Fed-
eral Government and Burlington Northern, Inc. The State
of Montana is the next-largest  owner of coal in south-
eastern  Montana,  as  two  sections per township were
granted to  the state for school land. Private individuals
own some coal throughout the area.

   The VS. Bureau of Land Management and US. Forest
Service in the Decker-Birney resource study (1972), esti-
mated the coal ownership in the Decker-Birney area (an
area south of the land grant to  Burlington Northern, Inc.)
as 88% federal, 5% state, and 7% private. Of the federally-
owned coal, 18% is within the boundaries of the Custer
National Forest. The  surface ownership in the Decker-
Birney resource study  area is 26% federal (17% within
the Custer National Forest), 5% state, and 69% private.

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                                              PREVIOUS GEOLOGIC WORK
                                                                                                       Ekalaka
                                       Figure 2.—Index map showing areas of previous coal studies.
 1.  1909. COLLIER, A.J., and SMITH, C.D., The Miles City coal
    field, Montana: U.S. Geol. Survey Bull. 341-A, p. 36-61.
 2.  1910. WEGEMANN, C.H., Notes on coals of Custer National
    Forest, Montana: U.S. Geol. Survey Bull. 381-A, p. 108-114.
 3.  1912. BOWEN, C.F., The Baker lignite field, Custer County,
    Montana: U.S. Geol. Survey Bull. 471-D, p. 202-226.
 4.  1924. BAUER, C.M., The Ekalaka lignite field, southeastern
    Montana: U.S. Geol. Survey Bull. 751-F, p. 231-267.
 5.  1929. BAKER, A.A., The northward extension of the Sheridan
    coal field, Big Horn and  Rosebud  Counties,  Montana:  U.S.
    Geol. Survey Bull. 806-B, p. 15-67.
 6.  1930. DOBBIN,  C.E., The  Forsyth  coal field, Rosebud,
    Treasure, and Big Horn Counties, Montana: U.S. Geol. Survey
    Bull. 812-A, p. 1-55.
 7.  1932. BASS,  N.W., The Ashland coal field, Rosebud, Powder
    River, and Custer Counties, Montana: U.S. Geol. Survey Bull.
    831-B,p. 19-105.
 8.  1936. PIERCE, W.C., The Rosebud coal field, Rosebud and
    Custer Counties, Montana: U.S. Geol. Survey Bull. 847-B,
    p. 43-120.
 9.  1939. PARKER,  F.S.,  and ANDREWS, D.A., The Mizpah
    coal field, Custer County, Montana: U.S. Geol. Survey Bull.
    906-C, p. 85-133.
10.  1952. BRYSON, R.P., The Coalwood coal field. Powder River
    County,  Montana: U.S. Geol. Survey Bull. 973-B, p. 23-106.
11.  1954. BROWN, ANDREW, and others, Strippable  coal  in
    Custer and Powder River Counties, Montana: U.S. Geol. Sur-
    vey Bull. 995-E, p. 151-199.
12.  1954. KEPFERLE, R.C., Selected deposits of Strippable coal
    in central Rosebud County, Montana: U.S. Geol. Survey Bull.
    995-1, p. 333-381.
13.  1959. WARREN, W.C., Reconnaissance geology of theBimey-
    Broadus coal field, Rosebud and Powder River Counties, Mon-
    tana: U.S. Geol. Survey Bull. 1072-J, p. 561-585.
14.  1966. BRYSON, R.P., and BASS, N.W., Geologic map and
    coal sections of the Moorhead coal field, Montana: U.S. Geol.
    Survey Open-file Rept., 37 fig., 3 tables, in 15 sheets.
15.  1969. GILMOUR, E.H., and WILLIAMS, L.A., Geology and
    coal resources of the Foster Creek coal deposit, eastern Mon-
    tana: Montana Bur. Mines and Geology Bull. 73, 9 p.
    	Northern Pacific Railway Company cooperative proj-
    ects with the Montana Bureau of Mines and Geology in 1966
    and 1967.
16.  1968.MATSON,R.E.,DAHL,G.G.,JR..andBLUMER, J.W.,
    Strippable coal deposits on state land, Powder River County,
    Montana: Montana Bur. Mines and Geology Bull. 69, 81 p.
17.  1935. THOM, W.T., JR., HALL, G.M., WEGEMANN, C.H.,
    and MOULTON, G.F., Geology of Big Horn County and the
    Crow Indian Reservation, Montana, with special reference to
    the water, coal, oil, and gas resources: U.S. Geol. Survey Bull
    856, 200 p.
18.  1967. CARM1CHAEL, V.W., The Pumpkin Creek lignite de-
    posit. Powder River County, Montana: Unpub. thesis, 79 p.
19.  1923. ROGERS, G.S., and LEE, WALLACE, Geology of the
    Tullock  Creek coal field. Rosebud and Big Horn Counties,
    Montana: U.S. Geol. Survey Bull. 749, 181 p.
20.  1972. LAW, B.E., and GRAZ1S, S.L., Preliminary geologic
    map and coal resources of the Decker quadrangle, Big Horn
    County, Montana: U.S. Geol. Survey Open-file Rept., 3 sheets.

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                                STR1PPABLE COAL, SOUTHEASTERN MONTANA

                                             GEOGRAPHY
       SURFACE FEATURES AND LAND USE

   The principal surface features in the study area are the
north-  and  northeast-trending  drainages  of Rosebud
Creek,  Tongue River, Powder River, and the larger tribu-
taries of the Tongue River such as Hanging Woman Creek,
Otter Creek, and Pumpkin Creek. All of these occupy
broad valleys, which abut the edges of steep-sided ridges.
The  ridges are  benched where resistant clinker  is en-
countered. The tops of most of the divides are gently
rolling  and covered with grass. Ponderosa pine thrives on
the areas of clinker and also marks the breaks where the
sides steepen and become dissected.

   Livestock grazing is the principal land use. Some hay
is  raised  in  meadows along the  major valley bottoms,
which  are either  irrigated or sub-irrigated, and some
grains,  such as wheat, oats, and barley, are cultivated. A
small lumbering industry is supported in and around the
Ashland area.

                   POPULATION

   Big  Horn, Rosebud, Powder River, and Custer Coun-
ties had a total population in 1970 of 23,993. As stated
previously, the area discussed in this report includes only
parts of these counties,  and the total population within
the report area would be somewhat fewer than the stated
figure.

   The population density of the four-county area ranges
between  0.9 person per square  mile  in Powder River
County and 3.2 persons per square mile in Custer County.
Big Horn County's population density is 2.0 persons per
square  mile; Rosebud County's is 1.2 persons per square
mile. From 1950 to  1970, Big Horn, Custer, and Powder
River Counties had a small increase in population, while
Rosebud  County had an 8.2% decrease. The trend has al-
ready been reversed in Rosebud County as a result of the
increased mining and construction activity at Colstrip.

               TRANSPORTATION

   The aiea discussed in this report is served by Burling-
ton Northern, Inc., and  by the Chicago-Milwaukee-Saint
Paul Pacific Railroad, both of which pass through Forsyth
along the Yellowstone River. The Milwaukee turns north-
west at Forsyth and passes through Roundup to the west.
The  Burlington Northern follows the south side of the
Yellowstone River eastward through Miles City and west-
ward through Billings. The southern part of the area is tra-
versed  by the  Burlington Northern line that  extends
southeastward from Huntley  (a  short distance east of
Billings) through Sheridan and Gillette, Wyoming, and
into the midwest. Burlington Northern spur lines extend
south from a point west of Forsyth to Colstrip to serve
the Western Energy mine and  Peabody Coal Company's
Big Sky mine, and south along Sarpy Creek to the West-
moreland Coal Company mine. A third  spur starting a
short  distance east of Sheridan  extends northward to
Decker to serve the Decker Coal Company mine.

   Interstate  Highway 94 passes through Forsyth and
eastward through Miles City and  westward through Bil-
lings. Interstate Highway 90 extends from Billings south-
eastward through Sheridan, Wyoming. The central part
of the area is traversed by US. Highway 212 from Billings,
through Hardin, Crow Agency, and Broadus to Colony,
Wyoming, and by U.S. Highway 312 connecting Broadus
and Miles City. Highway 315 extends from a junction a
few miles west of Forsyth southward to Colstrip and
Lame Deer. A blacktop road extends from Acme, Wyo-
ming, to a junction a few miles north of Decker, and an-
other blacktop road extends from Busby south to the
south boundary of the Northern Cheyenne Indian Reser-
vation. Highway 319, at the  eastern  edge of the area,
connects Broadus with Gillette, Wyoming. Improved
roads follow  the Tongue River north of Decker to the
junction with Highway 312 a few miles south of Miles
City. Other improved roads connect Ashland, Otter Creek,
and Hanging Woman Creek to Decker. Most of the other
roads are gravel or graded dirt roads that become difficult
to use during periods of heavy precipitation and during
the winter.

                     CLIMATE

   The climate of Big Horn, Powder River, Rosebud, and
Custer Counties is characterized by warm summers, cold
winters, and  pronounced variations in seasonal precipi-
tation.

   Although  the annual precipitation in  the area varies
from less than 12 inches to 16 inches a year, depending
on the location or the altitude, the greatest amount of
precipitation  generally occurs at the  highest altitudes
such as the divides between the major drainages. April,
May, June, July, and August are  the periods of heaviest
precipitation. The largest average monthly precipitation
is  during June. The highest temperatures occur in July
and the lowest in January; the annual mean temperature
is about 45 degrees.

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                                             STRATIGRAPHY
                 WATER SUPPLY

   The area is drained by the northward- and  north-
eastward-flowing Rosebud Creek, Powder River, Tongue
River,  and their tributaries.  All major drainages enter
Yellowstone River. Rosebud Creek joins it near Rosebud,
which is east of Forsyth, the Tongue River enters at Miles
City,  and the Powder River near  Terry. The principal
tributaries of the Tongue River, such as Pumpkin Creek,
Otter Creek, and Hanging Woman Creek, and the princi-
pal tributary of the Powder River,  Mizpah Creek, are all
intermittent streams. That is, at times there is no flow al-
though water stands in ponds or pools throughout the
year.  The maximum discharge in  the major drainages
normally is during the spring runoff in May and June.
Powder River has flooded  during periods of heavy pre-
cipitation. Gaging stations of the U.S. Geological Survey
are located on the Powder River near Moorhead  and at
locations south of Terry, on the Little Powder River near
Broadus,  and on the Tongue River  below  the Tongue
River Dam and near Miles City. Sites for collecting data
on the quality of water are at Decker and near Miles City
on the Tongue River.

   The Tongue River Reservoir in T. 8 and 9  S., R.40 E.,
has a present storage capacity estimated at 68,000 acre-
feet, and of this amount, 32,000 acre-feet is under con-
tract for irrigation. Before water  can  be used for any
other purpose, the approval of the Tongue  River Water
Users Association is needed.  An engineering study of a
high Tongue River dam, proposed to be constructed sev-
eral miles north of the present dam, has been completed
for the Montana Department of Natural Resources by
Bechtel Corporation. Another site, which would provide
industrial water, is the proposed Moorhead dam and res-
ervoir a few miles north of the Montana-Wyoming bor-
der.  The proposed reservoir would have a capacity of
1,150,000 acre-feet, of which approximately 92,500 acre-
feet would be allocated for industrial use.

   Except for Rosebud Creek, Powder River, and Tongue
River, very little surface water is available in the area. Al-
though numerous small reservoirs along the tributaries of
the major drainages provide small supplies of stock water,
most water for domestic, livestock, and agricultural use
is obtained from wells. The  alluvium along the drainages
and the sandstone and coal  beds in the Fort Union and
Hell  Creek Formations  (Perry, 1935,  p. 40-43) are the
principal sources of ground water. Interest in the develop-
ment of coal deposits has stimulated  evaluation of the
ground-water resources. Current work by  the Montana
Bureau  of Mines  and Geology  Hydrology Division in-
cludes  water-evaluation studies at the  Decker mine site,
in an area west of Decker  at Youngs Creek in T. 9 S.,
R. 38 E., which is on the Crow Indian Reservation, at
Western Energy mine at Colstrip, and at Westmoreland
Resources mine at Sarpy Creek. The Billings office of the
U.S. Geological Survey is conducting an inventory on
water levels  and water quality throughout the Montana
portion of the Powder River  Basin.
                                           STRATIGRAPHY
            FORT UNION FORMATION
   The coal beds  described in this report  are in the
Tongue River  Member of the Fort Union  Formation
(Paleocene). The  Fort Union includes  three members
which are, from top to bottom, the Tongue River, Lebo,
and Tulloch.

   The Fort Union Formation was named by Meek and
Hayden (1861, p. 433) for old Fort Union, which was
situated near the junction of the Missouri and Yellowstone
Rivers. Subsequent field work in eastern Montana resulted
in the division of the Fort Union into three members on
the basis of color, lithology, topographic expression, and
occurrence  of  coal, which  were convenient  criteria for
division of the formation into mappable units.

   Along the Yellowstone  River between Rosebud and
Glendive, the Fort Union Formation is divisible into its
members on the basis of color alone—the dark Lebo bed
contrasts with  the light-colored Tulloch  beds below and
the light-colored Tongue River beds above-but the color
differences are not in themselves distinctive in all areas of
eastern Montana. Farther west, towards the source of the
sediments, the dark and the lower light zones lose their
identity and merge to form a greenish-gray or gray sandy
sequence (Brown, 1962, p. 3). Farther southeast and east,
and in western North Dakota, the lower members cannot
be distinguished from one another and together are re-
ferred to as the lower member in Montana (Bryson,  1952,
p. 46-52) and as the Ludlow in North Dakota (Brown,
1962, p. 6).


   The base of the Fort Union was defined by Bamum
Brown (1907, p. 834) as the base of the lowest coal bed
above the dinosaur-containing  beds of the Hell Creek
Formation (late  Cretaceous). Although many writers have
attempted to re-define the Cretaceous-Paleocene bound-
ary, Roland Brown (1962, p. 11) concluded after many
years of study that the use of the lowest coal bed as the
boundary is still valid, and where the coal is missing, the
Cretaceous-Paleocene contact can be closely determined
from paleontological evidence.

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8
                                 STRIPPABLE COAL, SOUTHEASTERN MONTANA
   The greatest difference is between the Lebo and the
members underlying and overlying it. The Lebo consists
of dark, drab, somber beds composed or dark-gray to
olive-gray shale containing altered and devitrified volcanic
ash and abundant brown ferruginous concretions (Rogers
and Lee, 1923, p. 36-39), whereas the Tulloch and Tongue
River are both light-colored interbedded fine-grained
sandstone, clay stone, and siltstone and also show simi-
larities in topographic expression. The Lebo, because of
its relative softness, characteristically erodes to form long
gentle slopes, whereas the Tulloch and Tongue River both
form steep escarpments  capped by the resistant  sand-
stone beds that are  prominent in both members. The
Tongue River Member is further characterized by  thick
layers of reddish  clinker, which have resulted from the
burning of the thick coal beds.

              TONGUE RIVER MEMBER

   The Tongue River Member was named by Taff (1909,
p. 129) in describing coal beds exposed along the valley
of the Tongue River in the Sheridan coal field, Wyoming.
The  high divide between the Tongue River and Rosebud
Creek near Brandenburg, Montana (Balster, 1971), is now
regarded as the type locality, as a more nearly complete
section is exposed there.

   In the area described in this report, the thickness of
the Tongue  River Member ranges from  1,200 to 1,700
feet. In many places, the upper part has been eroded or
truncated especially  in  the northern  part of the  area
where the section consists of only the lower few hundred
feet.

   The Tongue River Member is characterized by pale-
olive to yellowish-gray fine-grained sandstone, yellowish-
gray claystone, interbedded  claystone and  sandstone,
interbedded  shale  and claystone, thick coal  beds, and
carbonaceous shale.  The sandstone beds and the clay-
stone sequences occur in almost equal proportions. The
sandstone beds, at various stratigraphic levels, form num-
erous cliffs, knobs, and pinnacles. The environment of
deposition was continental, including abundant swamps
that produced coal in a cyclic depositional sequence. The
thick coal beds are the major interest in this report, and
on the various  overburden maps (PI. 1 through PI. 32),
twenty-six individual coal beds are  shown. Perhaps the
most striking characteristic of the Tongue River Member
is the clinker, which was formed by the burning of the
underlying thick coal beds and which  covers large areas.
This burning has caused fusion and baking of the strata
overlying the coal bed  and has produced a reddish to
orange multicolored zone. In some places, these clinker
zones are more than 200 feet thick. The thickness of the
clinker, which is roughly proportional to the thickness of
the coal, is one factor utilized in exploration.

   The thicker coal beds have burned near their outcrop
and back from their outcrop throughout the study area.
This phenomenon is attributed to spontaneous combus-
tion, which results where thicker coal  beds containing
moderate to high volatile matter  are exposed at the sur-
face. There the coal can slack and become finely divided,
and if it is subjected to a small increment of outside heat,
such as the direct rays of the sun  during the summer
months, combustion begins and persists if the amount of
coal is adequate  to retain the heat (Rogers, 1918, p. 2).
The burning of the coal beds has affected the overlying
sediments to varying extent  by strictly thermal meta-
morphism. The alteration of the  sedimentary rocks pro-
duces a very striking change from the original yellowish
gray to bright yellow, red, and orange.

   In North Dakota, what is known in Montana as the
Tongue  River Member has been divided into the Sentinel
Butte Member  (upper) and the  Tongue River Member
(lower)  on the basis of a color change from the typical
buff or yellowish-gray below  to somber gray shale beds
above (Royse, 1972, p. 32).

                   LEBO MEMBER

   The  Lebo Member of the Fort Union  Formation,
which underlies the Tongue River Member, is 300 to 600
feet thick within the report area. Except for the basal
coal bed,  called the  "Big Dirty", the Lebo is  devoid of
coal beds. The "Big Dirty" coal bed has been utilized as
fuel by  local ranchers, but in most places it contains so
much carbonaceous shale  that it produces too much ash.

   The type locality of the Lebo is on Lebo Creek, north
of the Crazy Mountains  in central Montana, where the
unit contains abundant andesitic sandstone (Stone and
Calvert, 1910). In eastern  Montana, as already stated, the
Lebo is composed of dark-gray shale, contrasting strongly
with the light-colored Tongue River above and the light-
colored Tulloch below. Topographically, the Lebo forms
badlands because the weathered rock does not support
vegetation.

                 TULLOCH MEMBER

   The Tulloch  Member  of the  Fort Union Formation
consists of a sequence of beds of yellow  sandstone, sandy
shale, carbonaceous  shale, and  numerous thin impure
coal beds  and is 275 to 500 .feet thick in the study area.
The top of the Tulloch is defined as the base of the "Big
Dirty" coal bed,  and the base is defined as the base of the

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                                              BURNED AREAS
coal bed above the dinosaur-containing beds of the Hell
Creek Formation, of late Cretaceous age (Brown, 1907,
p. 834). The type locality of the Tulloch is the valley of
Tulloch Creek, Treasure County, Montana,  where the
unit is about 270 feet thick. Although in this area it con-
tains ten lenticular coal beds, none of them is of adequate
quantity or quality to be economically recoverable.

              WASATCH FORMATION

   The  Wasatch Formation  (Eocene) overlies the Fort
Union in a few places. It is about 500 feet thick in the
Powder River Basin along the Montana-Wyoming border,
where it consists of varicolored clayitone, sandstone, and
shale. It contains a richly fossQiferous zone, as much as
30 feet thick, not  more than 30 feet above the Roland
coal  bed (Baker,  1929, p. 34; Olive, 1957, p. 29). In
some areas it is very arkosic and contains abundant con-
glomerate of granitic pebbles (Balster, 1971, p. 42).

   The top of the Roland coal bed marks the base of the
Wasatch Formation.  In the  Wyoming portion  of the
Powder River Basin, the Wasatch Formation contains
commercial  coal.
                                        GEOLOGIC STRUCTURE
   The area discussed in this report lies in the northern
part of the Powder River Basin. The structural history
has been discussed by numerous authors (McGrew, 1971;
Curry, 1971, Wyoming Geological Association, 1965).
The Miles City Arch-Cedar Creek Anticline separates it
from the Williston Basin to the northeast; the Black Hills
are adjacent on the southeast, and the Big Horn Moun-
tains are adjacent on the west. The Powder River Basin is
asymmetrical, its axis being nearer the west side.
   A structure contour map (Fig. 3, from Balster, 1973)
of a persistent bentonite marker below  the Greenhorn
Formation  (upper Cretaceous) shows that the lowest
point in the Montana portion of the Powder River Basin
is on the Wyoming border. The structural relief from the
northern part of the area to the lowest point  is 2,500
feet. The structure of the Paleocene roughly conforms
to this  Cretaceous  structure,  but  reversals have been
noted.
                                                  COAL
                 COAL QUANTITY
   The strippable coal resources in the deposits discussed
in this report total 32,024,930,000 tons underlying
770,079 acres (Table 1). Many areas smaller than those
included in this report have been omitted intentionally
01 in some cases inadvertently. The coal beds are fairly
evenly distributed throughout the Tongue River Member,
and most are remarkably free of parting. Columnar charts
show the  generalized relationships of the various coal
beds in the northern part of the  area to  one another in
each coal field, as well as from one coal field to another,
as described in previous reports by the U.S. Geological
Survey (Fig. 4). Staggered cross sections show tentative
correlations of most of the major coal beds containing
strippable  reserves (PI. 33,34). Certain areas, such as the
Greenleaf Creek-Miller Creek coal field (PI. 30), the Col-
strip coal field (PI. 14), the Sweeney Creek-Snyder Creek
coal  field (PI. 22), the Sand Creek coal field (PI. 28), the
Pine Hills coal field (PI. 31), and the Knowlton coal field
(PI. 32) are not shown on the cross sections.

              BURNING OF THE COAL

   Large parts of the original near-surface coal reserves
of the Tongue River Member have been destroyed by
burning at their outcrop and beneath shallow cover. Al-
most everywhere, each coal bed more than 5 feet thick
and of good quality has burned, and the heat has pro-
duced brightly colored clinker. Because of its appearance,
this clinker is miscalled "scoria", "red  shale", or "lava
rock". The rocks overlying a burned coal bed have been
altered,  baked, and fused  by thermal metamorphism
(Rogers, 1918, p. 1-10).

   The amount of alteration of the overlying material is
roughly proportional to the original thickness and qual-
ity of the coal that  has burned. Thickness of clinker can
therefore be utilized in exploration as an added indication
of the thickness and quality of a coal bed. A coal bed 5
to 10 feet thick will  produce a clinker zone 10 to 30 feet
thick, whereas a coal bed 50 feet thick may produce a
clinker zone 100 to 200 feet thick.

   The bright red, orange,  yellow, and  black clinker is
used locally to surface and  improve roads. Some of the
fused blocks are utilized as a building material for such
structures as fireplaces.

   As the clinkered  areas are porous and permeable, nu-
merous  springs emerge along  the  base of the  clinker.
Clinkered areas also support the growth of ponderosa
pine and other vegetation along the sides of ridges.

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10
8TRVPABLB COAL, SOUTHBABTBRM MONTANA
                                               Scale
                                                     20         30
                                              4O Miles
                                    Contour  interval  100 feet
                                              Upper GnfeceoM, Montana portion

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                                              RESERVES
                                                                                                    11
                   Table l.-Coal reserve*, acreage, and tons per acre, selected strippabto coal deposits.

Coal deposit                Plate no.   Coal bed

Decker                       1      Anderson and Dietz 1 & 2
Deer Creek                    2      Anderson and Dietz 1 & 2
Roland                       3      Roland
Squirrel Creek                 4      Roland
Kirby                        5A    Anderson
                                    Wall
                             SB    Dietz
                             5C    Canyon
                             6      Wall
                                    Brewster-Arnold
                             7      Brewster-Arnold
                             8      Anderson and Dietz
                             9A    Anderson
                             9B    Dietz
                            10A    Anderson
                            10B    Dietz
                            IOC    Canyon
                            11A    Knobloch
                            11B    Knobloch
                            12      Knobloch
                            13A    Knobloch
                            13B    Sawyer, A and C
                            14      Rosebud
                            15      Sawyer
                            16A    Knobloch
                            16B    Tenet
                            16C    Flowers-Goodale
                            17      Broadus
                            18      T
                            19      Canyon
                            20      Cook
                            21      Pawnee and Cook
                            22      Terret
                            23A    Elk and Dunning
                            23B    Cook
                            24      Canyon and Ferry
                            25A    Pawnee
                            25B    Cook
                            26      Canyon and Ferry
                            27      A, Sawyer, C and D,X, and E
                            28      Knobloch
                            29      Flowers-Goodale, Terret, and
                                      Knobloch
                            30      Rosebud, Knobloch, and Sawyer
                            31      Dominy
                            32A    Dominy (M & L)
                            32B    Dominy (U)
Canyon Creek

Birney
Poker Jim Lookout
Hanging Woman Creek

West Moorhead
Poker Jim Creek-O'Dell Creek

Otter Creek
Ashland

Colstrip
Pumpkin Creek
Foster Creek
Broadus
East Moorhead
Diamond Butte
Goodspeed Butte
Fire Gulch
Sweeney Creek-Snyder Creek
Yager Butte

Threemile Buttes
Sonnette

Home Creek Butte
Little Pumpkin Creek
Sand Creek
Beaver Creek-Liscom Creek

Greenleaf Creek-Miller Creek
Pine Hills
Knowlton
Reserves,
million tons
2,239.99
495.65
218.04
133.41
216.52
473.69
834.35
158.53
1^84.25
65.86
180.55
872.65
1,583.29
1,120.96
883.74
397.49
690.19
373.29
564.78
2,075.55
2,696.20
357.49
1,439.26
2,426.50
708.13
460.87
258.90
739.82
525.21
418.02
628.95
336.69
326J3
1,175.86
312.02
225.40
320.25
362.98
217.21
215.83
267.34
627.49
453.71
193.87
747.51
120.31
Acreage
25,523
14,214
12,076
6,208
5,655
5,952
17,516
4,066
23,859
2,067
6,969
19,609
30,547
43,654
19,660
20,416
22,547
7,890
7,187
25,791
27,200
20,262
33,379
45,695
27,801
27,462
14,444
18,429
15,559
21^63
13,446
8,486
10,921
26,924
14,507
13,836
8^224
10,470
4,851
8,534
5,952
25,926
14,918
6,022
19,613
4,448
Average
tons/acre
87,763
35,397
18,055
21,490
38,285
79,579
47,630
38,983
78,974
31,859
25,905
44,501
51^30
25,678
44,949
19,469
30,611
47,311
78,581
80,475
99,125
17,643
43,118
53,102
25,470
16,782
17,924
40,142
33,756
19,566
46,775
39,674
29,880
43,673
21,507
16,289
38,940
34,668
44,774
25,290
44,915
24,203
30,413
32,191
38,112
27,048
                                                                  32,024.93
                                                                                 770,079

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             Forsyth   field
            (U.S.G.S. Bull.749)
                       Greenleof Cr-Miller Cr. field
                          (US.G.S.Bull. 831-B)
   Ashland field
(USGS.Bull 831-B)
                                                                                                             Pumpkin Cr  field
                                                                                                Foster Cr field
                                         Snyder  Cr  field
                                         (U.SG.S.Bull 847-
 TullocK
Cr  field
 (U.S.GS      >•'   |—
 Bull. 749)xx
                                                                                                                                            Pine Hills field
                                                                                                                                                                     CO
                                                                                                  69
                                                                                                  t"
                                                                                                  a
                                                                                                  o
                                                                                                  o
                                                                                                                                                                    t
                                                                                                                                                                    z
                                                                                                                                                                    X
                                                                                                                                                                    o
                                                                                                                                                                    z
                                     Figure 4.-Coluinnai sections showing relationship of coal beds in northern part of area.

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                                                QUALITY
                                                                                                        13
                  COAL QUALITY

   The coal in the deposits described in this report ranks
as lignite A through subbituminous A according to the
specifications of the American Society for Testing and
Materials (1964, p. 74). Under this classification system,
coal having calorific value  of 6,300  to 8,300 Btu per
pound on a moist, mineral-matter-free basis is classified
as lignite  A; coal  having a calorific value of 8,300 to
9,500 Btu  per pound is classified as  subbituminous C;
coal having a calorific value of 9,500 to 10,500 is classi-
fied as subbituminous B; and coal having a calorific value
of 10,500 to 11,500 is classified as subbituminous A.

   On this project, 457 core samples were obtained and
were  analyzed  in  the Montana  Bureau of Mines and
Geology analytical laboratories by or under the direction
of Laurence A. Wegelin. Proximate analysis, forms of sul-
fur, and calorific value and major ash  constituents were
determined in accordance with methods specified by the
American Society for Testing and Materials, Laboratory
Sampling and Analysis of Coal and Coke (1967) and the
U.S. Bureau of Mines (1967) methods of analyzing and
testing coal and coke. Constituents in the ash were deter-
mined  by  the  standard techniques supplemented by
atomic-absorption techniques, with the exceptions of sul-
fur, which was determined only gravimetrically, and phos-
phorus, which w^as determined only volumetrically.

   Samples obtained under cooperative projects of the
Montana Bureau of Mines and Geology with Burlington
Northern, Inc., were analyzed by the  Grand Forks Coal
Research Laboratory, U.S. Bureau of Mines. Samples ob-
tained from West Moorhead coal field in 1968 were ana-
lyzed by the Pittsburgh Coal Research Center, U.S. Bureau
of Mines. Major ash constituents of these samples were
analyzed by the U.S. Geological Survey Analytical Lab-
oratory in Washington, D.C. Trace-element analyses of
samples from the Decker area were made by the U.S.
Geological Survey Laboratories, Denver (U.S. Geological
Survey—Montana Bureau of Mines and Geology open file
report, 1973).

   With few exceptions, the coal is low in sulfur and has
low to moderate ash content. The calorific value on the
"as received" basis ranges from 6,500 Btu per pound in
the Knowlton coal field (PI. 32) to 9,850 Btu per pound
in the Decker coal field (PI.  1).

                    COAL BEDS

                 ROLAND COAL BED

   The Roland coal bed marks the top of the Tongue
River Member (Taff,  1909, p. 130), and the  top of the
Roland is defined as the contact with the Wasatch (Baker,
1929, p. 28). Although  no marked difference between
the Tongue River and Wasatch strata is visible in the field,
on aerial photos the Wasatch has a striated appearance,
particularly in the Decker area, which is not shown by
the Tongue River strata. The Roland bed is 180 to 220
feet above the Smith coal bed. Strippable reserves were
mapped in the Roland (PI. 3) and Squirrel Creek (PI. 4)
coal deposits.

   The Roland coal bed underlies the high divide areas in
the Decker (PI. 1), Deer Creek (PL 2), Hanging Woman
Creek (PI. 9), and West Moorhead (PI. 10A, B, and C).

   The Roland coal  in the Roland coal deposit ranges in
calorific value from  7,021 to 9,114 Btu, the sulfur con-
tent is 0.2 to 0.7%, and the ash content 3.8 to 9.7%. The
Roland  coal in the Squirrel Creek deposit ranges in cal-
orific value from 6,608 to 8,286 Btu, the sulfur content
is 0.2 to 0.6%, and the ash content 3.0 to 14.2%.

                  SMITH COAL BED

   The Smith coal bed, named by Taff (1909, p. 130) for
a mine of that name  in the Sheridan area, was traced into
the Decker, Hanging Woman Creek, and Kirby areas by
Baker (1929, p. 35)  and into the West Moorhead area by
Bryson and Bass (1966). Although small  areas containing
50 to 75 million tons of strippable coal are known in the
Smith coal bed,  in  the Decker (PI. 1) and Deer Creek
(PI. 2) coal deposits, they have not been included in this
report. In the West Moorhead coal field and in the Hang-
ing Woman Creek area, the Smith bed is thin and lies 110
to 150 feet above the Anderson coal bed. In the western
part  of the West Moorhead field, it is characterized by
petrified tree stumps. The bed is as much as 12 feet thick
in the Decker, Deer Creek, and Kirby areas.

   Only two core samples were obtained from the Smith
bed, both in the Decker coal deposit. The calorific values
were  7,607  and  8,272 Btu, the sulfur  content 0.6 and
1.0%, and the ash content 6.8 and 302%. Silica is a major
ash constituent,  being 38.5 and 78.3% of the total ash
content.

                ANDERSON COAL BED

   The Anderson coal bed, named by Baker (1929, p. 35),
is correlated with the Garfield bed (Matson, 1971, p. 7),
named by Bass (1932, p. 55). Strippable reserves in the
Anderson coal bed have been  mapped in  the  Decker
(PI.  1), Deer Creek (PI. 2), Kirby (PL  5A), Poker  Jim
Lookout (PI. 8), West Moorhead (PI. 10A), and Hanging
Woman Creek (PI. 9) coal fields.

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14
STRIPPABLE COAL, SOUTHEASTERN MONTANA
   The Anderson coal bed merges with the Dietz No. 1
bed at the Decker mine,  and their combined thickness
exceeds 50 feet. A short distance west of the mine, the
Anderson, Dietz No. 1, and Dietz No. 2 beds are com-
bined and have a thickness of 80 feet; still farther west,
the Anderson splits from the combined Dietz No. 1 and
No. 2 coal beds. In the Deer Creek coal field, the three
coal beds are separate, and the Anderson bed averages 20
feet in thickness.  In the Poker Jim Lookout coal field,
the Anderson and Dietz are combined in the northern
part of the field and form a coal bed 58 feet thick, but in
the southern part, they are separate beds. In the West
Moorhead coal field, the Anderson bed is  14 to 30 feet
thick  and lies 13 to 81  feet above  the Dietz No. 1 coal
bed and 120 to 200 feet above the Canyon coal bed. In
Hanging Woman Creek area, the Anderson coal bed is 25
to 36 feet thick except in the southwestern part of the
area, where it thins to 15 feet. It lies 50 to 100 feet above
the Dietz No. 1 bed.

   The Anderson coal bed in the Decker coal field has a
calorific value of 8,705 to 9,850 Btu, sulfur content of
0.2 to 0.6%, and ash content of 2.9 to 62%. In the Deer
Creek coal deposit, the  calorific value is 6,594 to 9,247
Btu, the sulfur content  0.4 to 0.8%, and the ash content
32 to 273%. In the Kirby coal deposit, the calorific value
is 7,277 to 8,864  Btu, the sulfur content is 0.2 to 0.7%,
and the ash content 3.2 to 8.1%. In the Poker Jim Look-
out coal field, the calorific value is 7,637 to 8,374 Btu,
the sulfur content 0.1 to 0.9%, and the ash content 4.0
to 8.9%. In the West Moorhead coal  field, the calorific
value  is 7,950 to  8,790 Btu,  the sulfur content 03 to
0.4%, and the ash content 42 to 6.7%. In the Hanging
Woman Creek coal deposit, the calorific value is 6,751 to
9,259  Btu, the sulfur content 0.1  to  0.8%, and the ash
content 3.0 to 9.1%.
                  DIETZ COAL BEDS

   The Dietz coal beds were named for the community
 of Dietz, about 5 miles north of Sheridan, Wyoming.
 Three Dietz coal beds were mapped in this locality (Taff,
 1909, p. 129) and traced northward into the Decker area
 (Baker, 1919, p. 35). The uppermost Dietz, or Dietz No. 1,
 is correlated with the Anderson bed in the Decker area,
 where the names Dietz No. 1 and No. 2 have been applied
 to the two coal beds underlying the Anderson, but these
 would probably correlate with the Dietz No. 2 and No. 3
 of Taff (1909). Strippable reserves in one or more of the
 Dietz coal beds have been mapped in the Decker (PI. 1),
 Deer Creek (PI. 2), Kirby (PI.  5B), Poker Jim Lookout
 (PI- 8), Hanging Woman Creek (PI. 9), and West Moorhead
 (PL  1 OB) coal deposits.
                          In the Decker area, the Dietz No. 1 and No. 2 combine
                       with the Anderson bed and have a combined thickness of
                       80 feet, but at the Decker mine, only the Dietz No. 1 is
                       combined with the Anderson to form one bed 50 feet
                       thick. In the Deer Creek coal field, the Dietz  No. 1 and
                       No. 2 are separated by partings, and each averages  18 feet
                       in thickness. In the Kirby coal deposit, the Dietz No. 1
                       and No. 2 have a combined thickness of almost 50 feet
                       in the southwest part of the  area, but split and thin to
                       the northeast. The Dietz No. 1 bed is combined with the
                       Anderson bed  in the northern  part  of the Poker Jim
                       Lookout deposit and forms a bed 58  feet thick, but splits
                       in the southern part of the deposit In the Hanging Woman
                       Creek coal deposit, the Dietz No. 1  bed reaches a maxi-
                       mum of 18 feet in thickness, but thins to about 4 feet in
                       the southwestern corner. In the West Moorhead deposit,
                       the Dietz No.  1 ranges from 6 to 11 feet in  thickness,
                       but seems to be thin or absent in the northeast corner.

                          The  Dietz coal bed in the Decker coal  deposit has a
                       calorific value of 6,019 to 9,373 Btu, sulfur content of
                       Q3 to 0.4%, and ash content of 2.9 to 6.3%. In the Deer
                       Creek coal deposit, the calorific value is 9,142 to 9,561
                       Btu, sulfur content 0.3 to 0.7%, and ash content 2.5 to
                       5.2%. In  the Kirby coal deposit, the calorific value is
                       7,467 to 9,502 Btu, sulfur content 03 to 2.4%, and ash
                       content 32 to 14.1%. In the Hanging Woman Creek coal
                       deposit, the calorific value is  7,722  to 8,707 Btu, sulfur
                       content 0.2 to 0.3%, and ash content 3.7 to 9.9%. In the
                       West Moorhead coal field, the calorific value is 7,907 to
                       8,080 Btu, sulfur content 03 to 0.7%, and  ash content
                       33 to  5.2%.

                                        CANYON COAL BED

                          The  Canyon coal bed, named by Baker (1929, p. 36),
                       is one of the most widespread  coal beds in the report area
                       and  contains strippable coal in such widely separated
                       areas as the West Moorhead  (PI. IOC), Kirby (PL 5C),
                       Diamond Butte (PI. 19), and Threemile Buttes (PI. 24)
                       coal deposits.

                          The  Canyon coal bed in the West Moorhead coal field
                       is 17 to 24 feet thick and lies 67 to 122 feet below the
                       Dietz coal bed. In the Kirby coal field, the Canyon is 16
                       to 25 feet thick and is 180 to 230 feet above the Wall
                       coal bed. In the Diamond Butte coal deposit, the Canyon
                       is 7 to 16 feet thick and is about 200  feet above the Cook
                       coal bed. In the Threemile Buttes coal deposit, the Can-
                       yon forms two benches 4 to 13 feet thick.

                          The  Canyon coal bed in the West Moorhead coal field
                       has a calorific value of 7,419 to 8,920 Btu, sulfur content
                       0.1 to 13%, and ash content 3.2 to 10.0%. In the Kirby

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                                                COAL BEDS
                                                                                                       15
coal deposit the calorific value is 8,446 to 9,113 Btu, sul-
fur content 0.2 to 03%, and ash content 32 to 10.7%.
In the Diamond Butte coal deposit, calorific value is
7,138 to 7,897 Btu, sulfur content 02 to 0.5%, and ash
content 3.3 to 5.2%. In the Threemile  Buttes coal de-
posit, the calorific value is 6,646 to 7,133 Btu, sulfur
content 0.4 to 2.5%, and ash content 3.8  to 8.7%.

                 FERRY COAL BED

   The Ferry  coal bed  consists of discontinuous lenses
underlying the high divide areas between  Pumpkin Creek
and tributaries of Otter Creek west and northwest of
Sonnette (Warren, 1959, p. 573). The Ferry coal bed cor-
relates with the F coal bed in the Ashland coal field
(Warren, 1959, p. 567).

   Strippable  reserves in the Ferry coal bed have been
mapped in the Threemile Buttes (PI. 24) and Home Creek
Butte (PI. 26) coal deposits.

   The Ferry  coal bed is 6 to 17 feet thick in the Three-
mile Buttes coal deposit and 24 feet thick in the Home
Creek Butte coal deposit, where it is about 76 feet below
the Canyon coal bed.

                  COOK COAL BED

   The Cook  coal bed,  between the Canyon above and
the Wall coal bed below,  forms two benches (Warren,
1959, p. 573). Strippable coal in the Cook coal bed has
been mapped  in the Sonnette (PI. 25B), Yager Butte
(PI. 23B), and Goodspeed Butte (PI. 20) coal fields.

   In  the Sonnette  area, the Cook bed occurs in two
benches 12 to 40 feet apart. The upper bench is 10 to 14
feet thick, and the lower bench is 5 to 10 feet thick. In
the Yager Butte coal deposit, the two benches are 38 to
75 feet apart; the upper bench is 0 to 19 feet thick, and
the lower bench is 8 to 11 feet thick. In the Goodspeed
Butte coal deposit, the parting between the two benches
is 34 to 45 feet thick; the  upper bench is 13 to 20 feet
thick, and the lower bench is 12 to 14 feet thick.

   The Cook coal bed in the Sonnette coal deposit has a
calorific value of 6,547  to  7,186 Btu, sulfur content 0.7
to 1.9%, and ash content 6.5 to 133%. In  the Yager Butte
coal field, the  calorific value is 5,881 to 7,703 Btu, sulfur
content 0.3 to 0.7%, and ash content 3.8 to 20.7%. In the
Goodspeed Butte coal deposit, the calorific value is 6,682
to 6,861 Btu, sulfur content \2 to 2.1%, and ash content
8.9 to 12.4%.
                  WALL COAL BED

   The Wall coal bed, named by Baker (1929, p. 37), has
large Strippable reserves, which have been mapped in the
Canyon Creek (PI. 6) and Kirby (PI. 5 A) coal fields, where
it is 50 to 60 feet thick. The Wall is 180 to 230 feet be-
low the Canyon bed.

   The Wall coal bed in the Canyon Creek coal deposit
has a calorific value of 7,637 to 10,079 Btu, sulfur con-
tent 0.1 to 1.1%, and ash content 3.1 to 12.5%.


                   ELK COAL BED

   The Elk coal bed, named by Warren (1959, p.  573),
crops out along the steep-sided valley of Otter Creek and
its tributaries. Strippable  coal has been mapped  in the
Yager Butte coal deposit (PI. 23A), where the bed is 10
to 21  feet thick. The Elk coal bed is 23 to 39 feet above
the Dunning bed.

   The Elk coal bed in the Yager Butte coal deposit has
a calorific value of 7,125 to 7,943 Btu, sulfur content
0.2 to 05%, and ash content 35 to 7.4%.


                 PAWNEE COAL BED

   The Pawnee coal bed, named by Warren (1959, p. 572),
forms two benches as much as 45 feet  apart in T. 4 S.,
R.47 and 48 E. Warren correlated the upper bench of the
Pawnee with the Dunning bed, but the  name Dunning is
used west  of the  Otter Creek-Pumpkin Creek divide.
Strippable coal in the Pawnee coal bed has been mapped
in the Sonnette (PI. 25A) and Fire Gulch (PI. 21) coal
deposits. The Pawnee coal bed is 20 to 22 feet thick in
much of the Sonnette coal field.

   The Pawnee coal bed in the Sonnette coal field has a
calorific value of 5,556 to 7,902 Btu, sulfur content 0.2
to 2.7%, and ash content 3.9 to 25.3%. In the Fire Gulch
coal deposit the heating value is 7,650 Btu, sulfur content
0.2%, and ash content 6.0%.


                DUNNING COAL BED

   The Dunning coal bed  crops out on the west side of
the Otter Creek-Pumpkin Creek divide. It was named by
Warren (1959, p. 572), who correlated it with the upper
bench of the Pawnee in the Sonnette coal field. It is 23
to 39  feet below the Elk coal bed. Strippable coal in the
Dunning coal bed is shown in the Yager Butte coal de-
posit (PI. 23A) where the bed is 14 to 20 feet thick.

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16
                                STRIPPABLE COAL. SOUTHEASTERN MONTANA
   The Dunning coal bed in the Yager Butte coal deposit
has a calorific value of 7,445 to 8,005 Btu, sulfur content
0.2 to 0.4%, and ash content 4.3 to 5.8%.

                    E COAL BED

   The E coal bed, named by Bass (1932, p. 55), is wide-
spread throughout the Ashland coal field. Strippable re-
serves were mapped in the Little Pumpkin Creek coal
field where the bed is 7 feet thick. The E bed is 70 to 100
feet above the X coal bed and is correlated with the Dun-
ning bed in the Birney-Broadus coal field to the south.

                    X COAL BED

   The X coal bed, about 8 feet thick, occurs locally in
T. 2 S., R. 46,47, and 48 E. (Bass, 1932, p. 55) and con-
tains  strippable coal in the Little Pumpkin Creek coal
field (PI. 27). The X bed is 40 to 80 feet above the C and
D coal bed and about 70 to 100 feet below the E coal bed.

                 C AND D COAL BEDS

   The C and D coal beds, named by Bass (1932, p. 55)
are two closely spaced coal beds in the Ashland coal field.
Strippable reserves in the C and D coal beds occur in the
Ashland coal field (PI. 13B), and the Little Pumpkin
Creek coal field (PI. 27). The C coal bed contains abun-
dant silicified tree stumps and log fragments and is easily
identified (Bass, 1932, p. 55).

   Prominent clinker in T. 2 S., R. 47 E., indicates that the
thickness of the D coal bed exceeds 10 feet. The bed at-
tains a thickness of 20 feet (Bass, 1932, p. 55) in T. 2 S.,
R. 45 and 46 E.

   The C and D coal beds are 80 to 100 feet above the
Sawyer in the Little Pumpkin Creek coal field (PI. 27).

            BREWSTER-ARNOLD COAL BED

   The Brewster-Arnold coal bed, named from a mine on
the Brewster-Arnold ranch in T.  6 S., R. 43 E., was cor-
related with the Sawyer coal bed (Baker, 1929, p. 38).
Strippable reserves have been  mapped in the Birney coal
field (PI. 7).

   The Brewster-Arnold bed is 235 to 275 feet below the
Wall coal  bed and is as much as 20 feet thick. A distinct
split is most pronounced west of the Tongue River.

   The Brewster-Arnold coal bed in the Birney coal field
has a calorific value of 7,987 to 9,417 Btu, sulfur content
0.2 to 0.7%, and ash content 3.1 to 8.2%.
                     T COAL BED

   The T coal bed, named by Bryson and Bass (1966), has
 been correlated with the Cache coal bed in the Birney-
 Broadus coal field (Warren, 1959, p. 572). The T coal
 bed is 15 to 25 feet thick and about 260 feet above the
 Broadus coal bed.

   Strippable reserves in the T coal bed have been mapped
 in the East Moorhead coal field (PI. 18).

   The T coal bed in the East Moorhead coal field has a
 calorific value of 6,867 to 7,592 Btu, sulfur content 0.3
 to 1.2%, and ash content 4.2 to 13.2%.

                 SAWYER COAL BED

   The Sawyer coal bed, named by Dobbin (1929), has
 been traced eastward into the Pumpkin Creek coal field
 (Bass, 1932, p. 52). Strippable coal in the Sawyer coal
 bed has been mapped in the Ashland (PI.  136), Little
 Pumpkin Creek (PI.  27), and Pumpkin Creek (PI. 15)
 coal fields.

   The Sawyer coal bed is 10 to 36 feet thick and lies on
 or as much as 100 feet above the A coal bed In the Little
 Pumpkin Creek coal  deposit (PI. 27), the C and D coal
 beds are 80 to  100 feet above the Sawyer (Bass, 1932,
 p. 52).

   The Sawyer coal bed in the Ashland coal deposit has
 calorific value of 7,740 to 7,965 Btu, sulfur content 0.3
 to 0.9%, and ash content 4.0 to 6.0%. In the Pumpkin
 Creek coal deposit, the calorific value is 7,140 to 7,570
 Btu, sulfur content 0.3 to 0.5%, and ash content 6.5 to
 10.0%.

                     A COAL BED

   The A coal bed, named by Bass (1932, p. 54), contains
 strippable  reserves in the Little Pumpkin Creek (PI. 27)
 and Pumpkin Creek (PI. 15) coal deposits. In T. 1 and 2S.,
 R. 47 and 48 E, and T. 2 S., R. 48 E., it is 6 to 15 feet thick
 and is 40 feet below the Sawyer coal bed, but elsewhere
• it may merge with the Sawyer or lie as much as 100 feet
 below it. Carmichael (1967, p. 43) therefore thought
 that the A coal bed may be a lower bench of the Sawyer.

                 KNOBLOCH COAL BED

   The Knobloch coal bed was named for the Knobloch
 ranch, on  the east side of the Tongue River in T. 5 S.,
 R. 43 E. (Bass, 1932, p. 52). It contains larger strippable
 reserves than any other mapped coal bed. These reserves

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                                                COAL BEDS
                                                                                                        17
are in the Poker Jim Creek-O*Dell Creek (PL 11A and B),
Otter Creek (PI.  12), Ashland (PI. ISA), Beaver Creek-
Liscom Creek (PI. 29), Foster Creek (PI. 16A), and Sand
Creek (PI. 28) coal deposits.

   The Knobloch is not uniform in thickness, and it de-
velops  partings and splits (PI. 34). Its maximum thick-
ness in the northern part of the Otter Creek (PI. 12) and
in the  Ashland coal  deposit (PI. 13A)  is 66 feet. The
Knobloch is 80 to 188 feet above the Flowers-Goodale
and 150 to 300 feet below the Sawyer coal bed.

   The Knobloch coal bed in the Poker Jim Creek-ODell
Creek coal deposit has a calorific value of 8,380 to 9,135
Btu,  sulfur content 0.1  to  0.6%, and ash content 3.7 to
6.4%. In the Otter Creek coal deposit, the calorific value
is 8,011 to 9,314 Btu, sulfur content 0.1 to 0.4%, and ash
content 3.0  to 10.6%. In the Ashland coal deposit, the
calorific value is 7,671 to 9,070 Btu, sulfur content 0.1
to 0.5%, and ash content 3.7 to 6.8%. In the Beaver Creek-
Liscom Creek coal deposit, the calorific value is 7,362
to 8,417 Btu, sulfur content 0.2 to 0.9%, and ash content
5.1 to 13.8%. In the Foster Creek coal deposit, the  cal-
orific value is 7,380 to 7,840 Btu, sulfur content 03 to
1.6%, and ash content  6.7 to 8.7%. In the Sand Creek
coal  deposit, the calorific  value is 7,220 to 7,460 Btu,
the sulfur content 0.3% average, and the ash content 5.1
to 8.3%.

                LAY CREEK COAL BED

   The Lay Creek coal bed, 2 to 6 feet thick, was named
by Bass (1932, p. 54) for Lay Creek,  which  is in  the
southwestern part of T. 1 N., R.46 E. The Lay Creek bed
is 30 to 88 feet below the Knobloch coal bed (PI. 29), is
of irregular thickness and quality, and does not contain
strippable reserves. In the  southwest part of the Beaver
Creek-Liscom Creek area (PI. 29) drill hole SH-7075 indi-
cates that the Lay Creek may be a split from the Knob-
loch, as the Knobloch splits and thins to the north.

                 ROSEBUD COAL BED

   The Rosebud coal bed was described by Dobbin (1929,
p. 27)  as being about 350 feet above the base of the
Tongue River Member. Mining on a large scale by Western
Energy Company and Peabody Coal Company in  the
Colstrip area gives the Rosebud bed special significance.
Strippable reserves in the  Rosebud coal bed have been
mapped in the Colstrip coal deposit (PI. 14).

   The Rosebud coal bed averages 25 feet in thickness in
the Colstrip coal deposit.  It  is 18 to 61 feet above the
McKay coal bed, which is 8 to 10 feet thick but which is
not discussed further in this report.

   The Rosebud coal bed in the Colstrip coal deposit has
a calorific value of 7,810 to 9,090 Btu, sulfur content 0.5
to 1.1%, and ash content 8.1 to 12.6%.

                BROADUS COAL BED

   The Broadus coal bed, named for the town of Broadus
(Warren,  1959, p. 570), is 100  feet above the base of
the Tongue River Member; strippable reserves have been
mapped in the Broadus coal deposit (PI. 17).

   The Broadus bed is 5 to  26 feet thick and was cor-
related by Bryson (1952, p. 75) with the Flowers-Goodale
bed.

   The Broadus coal bed in the Broadus coal deposit has
an average  calorific value of 7,438 Btu, sulfur content
averages 03%, and ash content averages 7.2%.

           FLOWERS-GOODALE COAL BED

   The Flowers-Goodale coal bed, named for the Flowers
mine in sec. 29 and the Goodale mine in sec. 28, T. 1 N.,
R. 45 E., both small wagon mines supplying coal to local
ranchers (Bass, 1932, p. 53), is 9 to 12 feet thick and con-
tains strippable reserves in the Beaver Creek-Liscom Creek
coal deposit (PI. 29).  It lies  80 to 188 feet below the
Knobloch and about 43 feet above the Terret coal bed.

   The Flowers-Goodale coal bed in  the Beaver Creek-
Liscom Creek coal  deposit has a calorific value of 8,102
Btu, sulfur content  1.0%, and ash content 8.1%.

                TERRET COAL BED

   The Terret coal  bed supplied coal to and was named
for the Terret ranch on Beaver Creek in T. 1 S., R.45 E.,
east of the  Tongue River (Bass, 1932, p. 51). The Tenet
coal bed  is  6 to 10  feet thick and contains strippable re-
serves in  the Beaver Creek-Liscom Creek area (PI. 29). It
is about 43  feet below  the Flowers-Goodale coal bed.

   The Terret coal bed in the Beaver Creek-Liscom Creek
coal deposit has a calorific value of 8,170 Btu, sulfur con-
tent 0.7%, and ash content of 5.8%.

                DOMINY COAL BED

   The Dominy coal bed was described  by Collier and
Smith (1909,  p. 56)  and was named for the Dominy

-------
18
STRIPPABLE COAL, SOUTHEASTERN MONTANA
ranch,  where the coal cropped out. Brown and others
(1954) described two benches of the Dominy, the lower
averaging 19 feet and the upper at least 6 feet in thick-
ness. Strippable reserves in the Dominy  coal bed  are
shown in the Pine Hills (PI. 31) and Knowlton (PI. 32A
and B) coal deposits. Project drill holes show the upper
bench to be 3 to 4 feet thick and the lower bench 17 to
20 feet thick.

   The Dominy coal bed in the Knowlton coal deposit
has a calorific value of 6,297 to 6,850 Btu, sulfur content
0.2 to 0.9%, and ash content 3.8 to 10.5%. In the Pine
Hills coal deposit, it has a calorific value of 7,220 to 7,420
Btu, sulfur content 0.4 to 0.6%, and ash content 6.6 to
8.1%.

               RESERVE ESTIMATES

   The coal reserve estimates in this report are classified
as "indicated" and "inferred" after Averitt (1965, p. 25).
Indicated reserves are  those calculated  on  a basis of spe-
cific measurements  and partly by projection of visible
data for a reasonable  distance, such as 2 or 3 miles for
coal  beds of known  continuity.  Inferred reserves  are
those based on a broad knowledge of the  geology of an
area and where few measurements of the thickness of the
coal  bed are available. Measured reserves  are limited to
areas  where data points for  thickness of the coal are
closely spaced and the quantity can be estimated accu-
rately. Small areas of measured reserves are included on
various  plates but are not separately distinguished. On
the other hand, areas  of inferred reserves  are shown on
the maps.
                          Overburden maps were drawn for each of the strip-
                       pable coal fields, and overburden thicknesses of 0 to 50,
                       50 to 100, 100 to 150,150 to 200, and 200 to 250 feet
                       were outlined on the maps. Where the coal is less than 10
                       feet thick, a limit of 100 feet was assigned as the maxi-
                       mum overburden. Other limits  used were  150 feet of
                       overburden where the coal is 10 to 25 feet thick, 200 feet
                       of overburden where the coal is 25 to 40 feet thick, and
                       250 feet of overburden where the coal is more than 40
                       feet thick. The areas between the overburden thickness
                       contours were then measured by a planimeter.

                          Coal reserves were then calculated from the average
                       thickness of the coal as shown on the isopach maps. Mea-
                       surements of the thickness of each coal  bed were suf-
                       ficiently numerous to assure a fair degree of accuracy in
                       estimation of coal  reserves.  In calculating the  coal re-
                       serves, the area as measured by planimeter was converted
                       to acres and the result multiplied by  the average coal
                       thickness to obtain the volume of coal in acre-feet. This
                       figure was then multiplied by  1,770 tons, the average
                       weight of an acre-foot of subbituminous coal (Averitt,
                        1965, p. 21), to yield the total tonnage.

                          From the same  planimeter data, the  overburden in
                       each  thickness range was calculated in cubic yards, and
                       the number of cubic yards of overburden per ton of coal
                       was computed for each overburden thickness range. The
                       acreage measured for each overburden thickness range is
                       reported, and the tons per acre under each overburden
                       thickness range is also  reported. Variations in the tons
                       per acre are accounted for by the irregularity in thickness
                       of the coal.
                                    STRIPPABLE COAL DEPOSITS
                  DECKER AREA


                     LOCATION


   The Decker area is in T. 8 and 9 S., R. 38,39,40,41, and
 42 E.,  Big Horn County, Montana, approximately 20
 miles northeast of Sheridan, Wyoming, by road. The maps
 outlining the strippable coal in the Decker area include
 the Decker (PI.  1), Deer Creek (PI. 2), Roland (PI. 3),
 and the Squirrel Creek (PI. 4) coal deposits. The area is
 bounded on the south by the Montana-Wyoming border,
 on the  west by the Crow Indian Reservation boundary,
 and on the east by the eastern side of the divide between
 Hanging Woman Creek and the Tongue River. The north-
 ern boundary of the area is the limit of strippable coal as
 indicated by the thickness of the clinker.
                                FIELD WORK AND MAP PREPARATION

                          The field work in the Decker area was done during the
                        summers of 1969, 1970, and 1972 under the EPA State
                        Coal Project. In order to solve some of the problems en-
                        countered by the U.S. Geological Survey while remapping
                        the area in 1971  and 1972, the  Bureau, under a U.S.
                        Geological Survey  Mineral Classification Branch Project,
                        drilled additional holes in 1972. Numerous drill logs were
                        provided by the Rosebud Coal Sales Company for prepar-
                        ing the overburden maps in the Decker and Deer Creek
                        areas.

                          The field methods utilized in evaluation of the strip-
                        pable coal in the Decker, Deer Creek, Roland, and Squirrel
                        Creek coal fields included geologic mapping on black-and-
                        white and color photos, drilling of numerous exploration

-------
                INDIVIDUAL DEPOSITS—DECKER AREA




Table 2.-Coal reserves, overburden, overburden ratio, acres, and tons/acre, Decker area.







     DECKER COAL DEPOSIT-ANDERSON, DIETZ 1, and DIETZ 2 BEDS
                                                                                 19
Thickness of
overburden, ft.
Oto 50
50 to 100
100 to 150
150 to 200
200 to 250
Indicated reserves
million tons
87.54
355.35
668.18
716.35
412.57
Total 2,239.99
Overburden and Overburden and
, interbuiden, interburden ratio,
million cu. yd. cubic yards/ton
78.40 0.89
697.73 1.96
1,743.36 2.60
1.887.62 2.63
U50.34 3.03
Total 5,657.45 Average 2.52 Total
Acres
1,433.6
5,689.6
8,467.2
6,553.6
3.379.2
25^23.2
Tons/acre
61,063.1
62,456.1
78,913.9
109,306.3
122.091.0
Average 87,763.5
DEER CREEK COAL DEPOSIT-ANDERSON, DIETZ 1, and DIETZ 2 BEDS
Oto 50
50 to 100
100 to 150

Thickness of
overburden, ft.
Oto 50
50 to 100
100 to 150

Thickness of
overburden, ft.
Oto 50
50 to 100

Oto 50
SO to 100
100 to 150
82.06
184.87
143.54
Total 410.47

Inferred reserves,
million tons
16.54
33.30
35.34
Total 85.18

Indicated reserves
million tons
110.29
107.75
Total 218.04

76.91
43.87
12.63
Total 133.41
372.87 4.54
1,443.81 7.8
1.787.75 12.45
Total 3,604.43 Average 8.78 Total
DEER CREEK COAL DEPOSIT-CORRAL CREEK BED
Overburden, Overburden ratio,
million cu. yd. cubic yards/ton
24.98 1.51
114.15 3.42
201.80 5.71
Total 340.93 Average 4.00 Total
ROLAND COAL DEPOSIT-ROLAND BED
Overburden, Overburden ratio,
million cu. yd. cubic yards/ton
327.45 2.97
716.32 6.64
Total 1,043.77 Average 4.79 Total
SQUIRREL CREEK COAL DEPOSIT-ROLAND BED
17.28 0.22
246.26 5.61
122.29 9.68
Total 385.83 Average 2.89 Total
2,400
5,344
4.064
11,808

Acres
467.2
940.8
998.4
2,406.4

Acres
6,156.3
5.920.0
12,076.3

3,571.2
2,035.2
601.6
6,208.0
34,191.7
34,593.9
35,319.9
Average 34,762

Tons/acre
35,402.4
35,395.4
35.396.6
Average 35,397.3

Tons/acre
17,914.9
18.200.1
Average 18,055.6

21,537.4
21,558.7
21.000.7
Average 21,490.9

-------
                                         Table 3.-Proxlmate analysis, forms of sulfur, and heating value, Decker coal field.
 Drill hole
 and location
SH-703
8S 40E S26
CCAB
SH-7010
8S40ES15
CBBA
SH-7017
8S38ES12
BCDC
SH-7018
95 40E S19
BCBA

BMC-727
8S 38E S36
CDBD

BMC-728
9S 39E S25
CDBA

BMC-729
9S 39E S29
CDBA
 Depth
 sampled
106 to
116ft.

116 to
126ft.

126 to
130 ft.
124 to
134 ft.

134 to
144 ft.

144 to
152ft.
142 to
148 ft.

148 to
159 ft.

159 to
165 ft.
215 to
218ft.
240to
247ft
231 to
232 ft.


116 to
127 ft.

127 to
137ft.

137 to
140 ft.
 Lab.
number
 160


 161


 162



 171


 172


 173



 187


 188


 189



 190



 462



 463



 464


 465


 466
  Coal
  bed
                       Canyon
                       Dictz
                      Anderson
                      Anderson
                      Dietz
                      Anderson
Anderson
Proximate, %
Form of
analysis
A
B
C
A
B
C
A
B
C
A
D
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
|
/ Moisture
20.910


23.810


23.870


27.100


24.130


17.310


25.790


21.750


27.070


20.590


25.910


21.730


24.040


25.150


25.300


Volatile
matter
26.314
33.271
42.357
32.544
42.714
44.575
30.709
40.338
41.699
29.476
40.433
44.230
29.933
39.453
41.147
21.218
25.659
44.313
32.350
43.592
46.244
34.987
44.712
46.902
32.443
44.485
46.932
34.109
42.953
46.250
31.619
42.677
44.392
32.589
41.636
43.935
30.836
40.595
42.780
30.514
40.767
42.426
29.200
39.090
42.629
Fixed
carbon
35.810
45.278
57.643
40.465
53.111
55.425
42.936
56.398
58.301
37.166
50.982
55.770
42.813
56.429
58.853
26.663
32.245
55.687
37.606
50.674
53.756
39.609
50.618
53.098
36.684
50.301
53.068
39.641
49.919
53.750
39.608
53.459
55.608
41.585
53.131
56.065
41.243
54.296
57.220
41.409
55.323
57.574
39.298
52.608
57.371

Ash
16.966
21.451

3.181
4.175

2.485
3.264

6.258
8.585

3.124
4.117

34.809
42.096

4.255
5.733

3.654
4.670

3.803
5.215

5.660
7.128

2.863
3.864

4.096
5.233

3.881
5.109

2.927
3.910

6.201
8.302


Sulfur
.730
.924
1.176
.146
.191
.200
.377
.495
.512
.431
.592
.647
.290
.382
.399
.371
.448
.774
.250
.337
.358
.188
.241
.252
.239
.328
.346
.283
.357
.384
.304
.411
.427
.246
.315
.332
.250
.329
.347
.231
.308
.321
.642
.859
.937
Form of sulfur, %

Sulfate
.017
.022
.028
.000
.000
.000
.009
.011
.012
.008
.011
.012
.009
.011
.012
.018
.021
.037
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.008
.011
.011
.008
.010
.011
.016
.021
.022
.016
.021
.022
.024
.032
.035

Pyritic
.313
.396
.504
.051
.068
.070
.043
.056
.058
.106
.145
.159
.077
.101
.106
.062
.075
.129
.089
.120
.127
.051
.066
.069
.080
.109
.115
.034
.043
.047
.055
.074
.077
.016
.021
.022
.040
.053
.056
.032
.042
.044
.079
.106
.116

Organic
.400
.506
.644
.094
.124
.129
.326
.428
.442
.317
.435
.476
.205
.270
.282
.291
.352
.608
.161
.218
.231
.137
.175
.184
.159
.219
.231
.249
.314
.338
.242
.326
.340
.222
.283
.299
.194
.255
.269
.183
.244
.254
.539
.721
.786
Heating
value (Btu)
8081
10218
13008
9691
12720
13274
9541
12532
12955

8769
12029
13159
9373
12355
12885
6019
7279
12571

9003
12132
12870
9436
12058
12649
8609
11805
12454

9850
12405
13357
9305
12559
13064
9768
12479
13168
9306
12252
12911
9212
12308
12808
8705
11654
12709










U)
H
2
s
13
2
5
o
o
f
CO
Q

H
S
>
CO
bj
M
S
*
3
o
2

>
2















1
 /A, as received; B, moisture free; C, moisture and ash free.

-------
                                     INDIVIDUAL DEPOSITS—DECKER AREA
                                                 21
holes, and field checking of the Rosebud Coal Sales Com-
pany drill data. Colored aerial photos of the area were
lent by the Carter Oil Company.

             PREVIOUS GEOLOGIC WORK

   The Decker and surrounding area was described by
Baker (1929) and by Ayler, Smith, and Deutman (1969),
and part is shown on a U.S. Geological Survey open-file
report on the Decker quadrangle (Law and Grazis, 1972).
Detailed maps on an engineering scale, prepared by Decker
Coal Company, were made available for reference.

                  LAND OWNERSHIP

   Because the Decker area lies south of the land grant to
Burlington Northern, Inc., the minerals under most of
the area are  owned by  the Federal Government. In sec.
16 and 36 of each township, granted  to the State of
Montana for school land, the  state has both the  surface
and the mineral rights.  In the  other sections, the Federal
Government generally retained the coal rights, even where
it deeded the surface.
         SURFACE FEATURES AND LAND USE

   The Tongue River  Reservoir now occupies much of
the broad valley of the Tongue River, which, like the
broad valley  of Deer Creek, is flanked by steep-sided
buttes and cliffs. Numerous drainages, which trend north-
west or southeast, are also bordered by steep-sided ridges
and buttes. Large areas of clinker in the northern part of
the area are hummocky and rolling, and the clinker zone
forms vertical cliffs where cut by drainages. All tributaries
of the Tongue  River are intermittent streams that flow
only during periods  of heavy precipitation and spring
runoff.

   Livestock grazing is the  principal use of land in the
area. A small amount  of hay is raised, especially on the
bottomland of Tongue River and Deer Creek valleys.


               GEOLOGIC STRUCTURE

   The geologic structure in the Decker area is more com-
plex than in most of the Powder River Basin; only Kirby
and some parts of the  Sheridan, Wyoming, area are  more
so. The  complexity of structure is probably due to the
proximity of the  Big Horn uplift and the axis of the
Powder River Basin. Furthermore, the Decker area is on
the north flank of the Ash Creek anticline, which con-
tains a producing oil field.
   Of the several prominent structural features in the
Decker coal field (PI-1), the most striking are the clearly
defined northeast and northwest lineations consisting of
fault-controlled topographic features. The northwest line-
ations are easily discernible, as they are followed by the
North and South Fork of Monument Creek, Spring Creek,
South Fork of Spring Creek, Pearson Creek, Squirrel
Creek, Dry Creek, and Youngs Creek.

   Except for the valley of Tongue River, the northeast-
trending features are not as obvious because the faults are
masked. These faults have the down-dropped block on
the southeast side except  in the South Fork of Spring
Creek, where the upthrown block is on the southeast side
of the fault. Three parallel faults in T. 9 S., R. 38,39, and
40 E., are difficult to follow for long distances, but in
some  places they have an apparent displacement  of as
much as 200 feet.

   The fault in sec. 16, T. 9 S., R.40 E., just south of the
Decker mining area, has a displacement of about 120 feet,
the southeast block being down-dropped, as shown by
drill hole  SH-7090 on the west line of sec. 22, T. 9 S.,
R. 40 E. The displacement along the fault in sec. 29 and 30,
T. 9 S., R.40 E., is also approximately 120 feet, the south
block being down-dropped. Strata in the Decker area dip
gently southeastward 40 to  69 feet per mfle except in
T. 8 S.,  R. 39  E., where the  dip is  about one degree. In
small areas, however, relatively steep dips are associated
with faulting, especially in sec. 21, T. 9 S., R. 40 E., and in
sec. 29 and 33, T. 9 S., R. 39 E.

   Altitudes of the top of the Roland  coal bed as deter-
mined by drilling in the Squirrel Creek coal field (PI. 4),
indicate a dip to the southwest.

   Prominent structural features in the Deer Creek coal
field (PI. 2) include the northwest lineation of the drain-
age patterns  of Deer  Creek and Corral Creek.  Three
northeast-trending faults have  been mapped in T. 9 S.,
R. 40 and 41 E. The down-thrown block is on the south-
east except on the southernmost  fault, which crosses
through sec.36,1.9 S.,R.40 E., and the NE& sec. 31 and
SEV4 sec. 30, T. 9 S., R. 41  E. There the down-thrown
block is on the north side (Law and Grazis, 1972). Struc-
ture contours in the Deer Creek deposit indicate that the
dip is to the southwest, but locally it is reversed. A small
syncline in sec. 12 and 13,T. 9 S., R. 40 E., occupies an
area where the distance between the  Anderson and the
underlying Dietz  No.  1 coal bed changes abruptly. The
dip in the south half of sec. 13 and extending into sec. 23,
T.9 S., R. 40 E., is about one  degree. In sec. 5,6, 7, and 8,
T. 9 S., R. 41 E., the  dip is relatively flat but steepens
again  farther northeast and again approaches one degree.

-------
                                                                                                                                                                        K)
                                                                                                                                                                        to
                                                          Table 4.-Trace-«lement analydf, Decker coal field.


                                                                (Semiquantitative 6-step ipectrographic)
Drillhole       Depth       Lab.         Coal
Element, ppm.
and location
BMC-723
8S41ES30
BDCD

BMC-727
8S 38E S36
CDBD
BMC-728
9S 39E S25
CDBA
BMC-729
9S 39E S29
CDBA




sampled

98 to
107 ft.
107 to
110ft.

240 to
247ft

231 to
232 ft.

116 to
127 ft. '
127 to
137 ft.
137 to
140 ft.
number bed
Dietz
458-
D160662
459-
D160663
Dietz
462-
D160666
Anderson
463-
D160667
Anderson
464-
D160668
465-
D160669
466-
D160670
B Ba Be Co Cr Ga La Mn Mo Nb Ni Sc Sn Sr Ti V Y Yb Zr
1500 15000 30 70 30 500 70 20 30 30 30 7000 5000 200 30 3 200
en
V
%
300 3000 7 30 70 30 70 200 70 20 30 30 3000 3000 300 50 5 150 >
5
0
o
1000 5000 20 70 30 500 100 20 30 20 15000 5000 300 30 3 150 >
ta
O
i
700 10000 15 50 20 500 200 20 20 20 30 7000 5000 150 30 3 200 >
n
§
S
O
700 7000 15 50 20 100 50 20 15 15 5000 5000 150 30 3 200 *
£
>
700 10000 15 50 30 150 30 15 15 7000 3000 150 20 2 100

300 7000 3 15 70 30 70 100 50 70 15 3000 3000 150 50 3 100


-------
Table 5.-Trace-element analysis of coal and ash, Decker coal field.
                  Element, ppm in coal
Element, ppm in ash
Drill hole
and location
BMC-723
8S 41E S30
BDCD




BMC-727
8S 38E S36
CDBD

BMC-728
9S 39E S25
CDBA
BMC-729
9S 39E S29
CDBA




Depth
sampled

98 to
107ft

107 to
110ft.


240 to
247 ft.


231 to
232 ft.

116 to
127 ft.
127 to
137 ft.
137 to
140 ft.
Lab. Coal
sample bed As F Hg Sb Se Te Tl U Cd Cu Li Pb Zn Ash%
Dietz 2 40 .035 43.3 <.l .1 <.2 <.2 335 27 185 3.20
458-
D160662

459- 2 30 .082 13.7 .4 .1 <.2 .8 1.5 385 130 275 180 6.80
D160663

Dietz 2 10 .037 4.7 <.l <.02 <.2 <.2 <1.0 420 50 545 175 3.25
462-
D160666

Anderson 3 10 .051 19.1 <.l .02 <.2 .4 <1.0 605 93 1660 195 4.56
463-
D160667
Anderson 1 30 .044 3.8 .2 <.02 <.2 <.2 <1.0 245 31 300 83 4.56
464-
D160668
465- 1 20 .030 1.9 <.l <02 <.2 <.2 <1.0 180 28 195 93 3.43
D160669
466- 3 30 .106 1.8 .6 <.02 <.2 1.2 1.5 145 44 120 240 7.12
D160670



z
2
D
i
0
W
g
f
g
o
so
>
%







                                                                                                             K)

-------
Table 6.-Major constituents of ash, Decker coal field.
Drill hole
and location

SH-703
8S 40E S26
CCAB
SH-7010
8S 40E S15
CBBA
SH-7017
8S38ES12
BCDC
SH-7018
9S 40E S19
BCBA

BMC-727
8S 38E S36
CDBD
BMC-728
9S 39E S25
CDBA
BMC-729
9S 39E S29
CDBA




Depth
sampled


106 to
130 ft.

124 to
152 ft.

142 to
165 ft.

215 to
218 ft.


240 to
247ft.-

231 to
232 ft.

116 to
127 ft.
127 to
137 ft.
137 to
140 ft.
Lab. Coal
number bed

Canyon

160-162
Dietz

171-173
Anderson

187-189
Anderson

190

Dietz
462-
D160666
Anderson
463-
D160667
Anderson
464-
D160668
464-
D160669
464-
D160670
Constituent, %
A1203

15.6


12.4


14.7


16.6



13.0


10.0


10.0


14.0

18.0

CaO

6.7


4.5


22.3


13.7



24.0


14.0


18.0


23.0

11.0

1*203

3.4


2.0


5.3


3.5



4.1


4.2


3.9


5.5

4.1

K20

1.4


1.9


.6


.5



.6


.3


.3


.4

1.3

MgO

1.4


1.8


5.2


2.5



8.7


3.3


9.3


12.3

5.7

Na20

7.0


2.2


8.8


6.4



2.3


6.1


1.8


1.9

.9

P205

.2


.4


.9


1.0



.2


.3


.7


4.4

3.8

Si02

48.2


61.6


29.7


42.0



16.0


37.0


41.0


14.0

25.0

SO3 TiO2 Total

10.9 .8 95.6


5.0 .8 92.6


10.9 1.1 99.5


8.4 2.2 96.8



20.0


12.0


13.0


16.0

16.0

CO
H
2
•O
to
M
O
O
r
en
O
G
SB
w
CO
H
n
V
z
s
o
2!
H
Z










-------
                                                   Table 7.-Proximate analysis, forms of sulfui, and heating value, Deer Creek coal field.
                                                                                      Proximate, %
Form of sulfur, %
Drillhole
and location
SH-7020
9S 40E S35
DBCD


SH-7022
9S41ES10
ADCD
BMC-723
8S41ES30
BDCD



Depth Lab. Coal
sampled number bed
Anderson
193 to
201 ft. 192
201 to
207 ft. 193
207 to
212 ft. 194
Smith
41 to
50 ft. 197
Dietz
98 to
107 ft. 458

107 to
110ft. 459
Form of
analysis / Moisture
A 24.770
B
C
A 25.550
B
C
A 19.270
B
C
A 27.900
B
C
A 24.840
B
C
A 25.350
B
C
Volatile
matter
32.136
42.717
45.012
32.912
44.207
46.210
21.066
26.094
39.438
31.309
43.424
47.982
31.163
41.462
42.922
31.116
41.682
44.785
Fixed
carbon
39.259
52.186
54.988
38.311
51.458
53.790
32.349
40.070
60.562
33.942
47.076
52.018
41.440
55.135
57.078
38.362
51.390
55.215

Ash
3.834
5.097
3.228
4.335

27.315
33.835
6.849
9.499

2.557
3.403

5.172
6.928


Sulfur
.777
1.033
1.088
.380
.510
.533
.733
.908
1.372
.591
.819
.905
.300
.399
.413
.725
.972
1.044

Sulfate
.017
.022
.023
.008
.011
.012
.026
.032
.048
.090
.125
.138
.016
.021
.022
.008
.010
.011

Pyritic
.314
.417
.440
.025
.033
.035
.284
.352
.533
.148
.205
.226
.032
.042
.043
.148
.199
.213 •

Organic
.446
.593
.625
.347
.466
.487
.422
.523
.791
.353
.489
.541
.253
.336
.348
.569
.763
.820
Heating
value (Btu)
9247
12291
12951
9179
12330
12888
6594
8168
12345
8272
11473
12678
9561
12722
13170
9142
12247
13158




I
D
r
DEPOSl
ITS— DECK
n
po
V






/A, as received; B, moisture free; C, moisture and ash free.

-------
26
STRIPPABLE COAL, SOUTHEASTERN MONTANA
This flexure has allowed exposure of the Anderson coal
bed along the valley bottom, and its subsequent burning
in sec. 3,4, and 9, T. 9 S., R. 41 E.

   In the Roland coal deposit (PI. 3) the structure of the
Roland  bed is irregular. The  highest  altitude exceeds
4,000 feet, as shown in drill hole SH-7024 in sec. 25, T. 8 S.,
R. 41 E., and the lowest is 3,656 feet, as shown in drill
hole SH-7021 in the southwestern part of the deposit.

                     COAL BEDS

   In the Decker area, coal beds in the upper part of the
Tongue River Member of the Fort Union Formation that
contain strippable coal include the Roland, Smith, Ander-
son, Dietz No.  1, and Dietz No. 2 coal beds. Because re-
serves in the Smith coal bed are small, they are not shown
on the maps. The coal beds in the Decker area have been
correlated with those in the Hanging Woman Creek and
Kirby areas (PI. 33).

   The major coal beds in the Decker area present an op-
portunity to study characteristics of coal-bed splitting
and coal-field  structure. Near  the  center of the Decker
coal deposit, the Anderson, Dietz No. 1, and Dietz No. 2
coal beds are combined into a single bed approximately
80 feet thick. At the Decker  mine, in sec. 16, T. 9 S.,
R. 40 E., east of the center of Plate 1, the Anderson and
Dietz No. 1 remain combined and form a bed approxi-
mately  50 feet thick, but  the Dietz No. 2 coal bed di-
verges from it and lies 50 feet below it. West of the center
of Plate 1, the  Dietz No. 1 and Dietz No. 2 remain com-
bined, but the Anderson bed splits from it.

   In the valleys of Spring Creek and South Fork of
Spring Creek in T. 8 S., R. 39 E., the combined thickness
of the Anderson, Dietz No. 1, and Dietz No. 2 coal aver-
ages 80 feet, but  reaches a maximum of 87 feet. In the
Squirrel Creek drainage, the thickness of the combination
also averages about 80 feet, and in the Youngs Creek area
it totals 73 feet, as shown in drill hole BMC-729, sec. 29,
T. 9 S., R. 39 E. The uppermost bed in this drill hole is
correlated with the Anderson bed and has a thickness of
35 feet. The underlying strata contain three coal beds 6,
 20, and 12 feet thick, which are correlated  with the
 Dietz No. 1 and Dietz No. 2 coal beds (PI. 1,33).

    In the northeastern part of the  Decker area, a promi-
 nent burn line marks the limit of unburned coal  in the
 Anderson and  Dietz No.  1 coal beds. The Dietz No. 2
 coal bed, however, contains strippable reserves beneath
 the clinker north and northeast into T. 8 S., R. 40 E. Be-
 neath the burn of the Anderson and Dietz No.  1, the
 Dietz No. 2 bed ranges from 14 to 20 feet in thickness.
    3 «
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                                                   —
-------
                                           Table 9.-Proximtte analysis, forms of sulfur, and besting value, Roland coal field.
 Drillhole
and location
SH-702
9S 40E S26
DDDA

SH-7019
9S 40E S36
ADDB

SH-7021
9S41ES19
BAAC
SH-7023
9S 41E S23
ACAB
SH-7024
8S41ES:5
ABCA

SH-7027
9S42ES18
BDCA

SH-7029
9S 42E S23
BBCB
 Depth      Lab.
sampled     number
 53 to
 63ft.
 74 to
 83ft.
 54 to
 60ft.

 60 to
 65ft.
 30 to
 31ft.

166 to
170 ft.
 53to
 63ft.
 52 to
 61 ft
 68 to
 76ft.
159



191



195


196



198


201



199



202



203
           Coal
           bed
                      Roland
                      Roland
                       Roland
Local



Smith


Roland



Roland



Roland
           Form of
A
B
C

A
B
C

A
B
C
A
B
C

A
B
C
A
B
C

A
B
C

A
B
C

A
B
C
                                                                                 ProximateL%
                                                                                                  Form of sulfur. %

Moisture
25.920


27.160


25.750


24.990


19.480


12.960


36.300


35.790


30.230


Volatile
matter
28.204
38.072
40.201
32.291
44.332
46.752
37.072
49.928
54.142
29.290
39.048
44.842
31.685
39.350
46.453
25.604
29.416
45.040
28.615
44.921
49.485
27.573
42.942
48.188
37.275
53.426
57.310
Fixed
carbon
41.953
56.632
59.799
36.778
50.491
53.248
31.400
42.289
45.858
36.028
48.031
55.158
36.524
45.360
53.547
31.243
35.895
54.960
29.211
45.857
50.515
29.647
46.172
51.812
27.767
39.798
42.690

Ash
3.924
5.296

3.771
5.177

5.779
7.783

9.691
12.920

12.311
15.289

30.193
34.689

5.875
9.223

6.990
10.886

4.728
6.776


Sulfur
.238
.321
.339
.193
.265
.279
.296
.399
.432
.250
.333
.382
3.562
4.424
5.222
.957
1.099
1.683
.674
1.058
1.166
.290
.452
.507
.235
.337
.362

Sulfate
.025
.034
.036
.008
.011
.012
.016
.022
.024
.017
.022
.025
.156
.194
.229
.037
.043
.065
.035
.056
.061
.021
.032
.036
.015
.022
.023

Pyritic
.076
.103
.109
.032
.044
.047
.066
.089
.096
.042
.055
.064
2.302
2.859
3.375
.409
.470
.719
.220
.345
.380
.062
.097
.109
.030
.044
.047

Organic
.136
.183
.194
.153
.210
.221
.214
.288
.312
.191
.255
.293
1.103
1.370
1.618
.511
.587
.899
.419
.657
.724
.207
.323
.362
.190
.272
.292
                                                                                             Heating
                                                                                            value (Btu)
8876
11981
12651
9114
12512
13196
8493
11438
12403
8417
11221
12886
8748
10864
12825
7607
8739
13381
7021
11022
12142
7120
11089
12443
8086
11590
12433




5
o
IVIDUAl
, DEPOSI'
»
I
pa
n







 /A, as received; B, moisture free;C, moisture and ash free.
                                                                                                                                                                   to
                                                                                                                                                                   •vl

-------
Table lO.-Major constituents of ash, Roland coal field.
4XAJU1 I1V1V
and location
SH-702
9S 40E S26
DDDA

SH-7019
9S 40E S36
ADDB

SH-7021
9S41ES19
BAAC
SH-7023
95 41E S23
ACAB


SH-7024
8S 41E S25
ABCA
SH-7027
9S42ES18
BDCA
SH-7029
9S 42E S23
BBCB
LSVJJUl
sampled

53 to
63ft.


74 to
83ft.


54 to
65ft.

30 to
31ft.
166 to
170 ft.

53 to-
63ft.

52 to
61ft.

68 to
76ft.
U1U.
number


159



191



195-196


198

201


199


202


203
V.UBI
bed
Roland



Roland



Roland


Local


Smith

Roland


Roland


Roland


Alj03
10.9



14.0



17.8


14.1


10.9

16.2


18.6


14.3


CaO
21.6



20.5



16.2


7.4


1.3

17.4


12.9


14.5


Fe,03
13.2



12.2



5.9


30.7


3.3

9.3


6.2


4.7


KjO
.2



.2



1.7


.9


1.7

.5


1.2


.3


MgO
4.4



3.4



2.8


3.4


.6

5.9


3.5


3.9


NajO
4.4



6.3



1.2


.8


1.4

.7


4.6


9.4


P20S
•°1.2



. 2.4



1.0


.1


.3

3.0


1.4


.4


SiO2
21.7



23.9



43.5


32.4


73.8

26.9


38.2


37.5


SO3
17.6



11.8



7.3


5.6


1.6

17.4


8.5


11.8


Ti02
.5



.6



.6


.5


.4

.5


.7


1.5


Total
95.7



95.3



98.0


95.9


95.3

97.8


95.8


98.3


1
B)
W
O
o

r*
CO
0
2
S
w
H
a
91
Z
2
O
•z
•-3
55
>







-------
                                        Table 11 .-Proximate analysis, forms of sulfur, and heating value, Squirrel Creek coal field.
                                                                              Proximate, %
                                                                                                  Form of sulfur. %
 Drillhole
and location
SH-7032
9SR39ES11
ACBB

SH-7033
8S R39E S34
BDAB
SH-7034
8S R39E S20
CDDB
SH-7035
9S R39E S21
BABA

SH-7036
9S R39E S17
ADCB
 Depth
sampled
 28 to
 36ft.
 38 to
 46ft.

 46 to
 48ft.
 35 to
 42ft.

 42 to
 46ft.
 35 to
 45ft.
 30 to
 33ft.

 33 to
 36ft.
 Lab.
number
 205
 206
                                207
 208
                                209
 210
 211
                                212
Coal
 bed
                      Roland
                      Roland
                      Roland
                      Roland
                      Roland
Form of
             A
             B
             C

             A
             B
             C
             A
             B
             C

             A
             B
             C
             A
             B
             C

             A
             B
             C

             A
             B
             C
             A
             B
             C
       1,

Moisture
34.090


29.750


30.050


30.520


28.560


28.710


36.710


31.730


Volatile
matter
24.607
37.334
47.562
31.200
44.412
47.525
28.709
41.043
45.367
29.108
41.895
43.965
31.124
43.567
45.816
30.578
42.892
44.749
28.155
44.486
46.892
28.152
41.236
44.987
Fixed
carbon
27.130
41.162
52.438
34.450
49.039
52.475
34.573
49.426
54.633
37.100
53.396
56.035
36.808
51.523
54.184
37.753
52.957
55.251
31.887
50.382
53.108
34.426
50.427
55.013

Ash
14.174
21.505

4.601
6.549

6.667
9.532

3.272
4.709

3.508
4.910

2.959
4.150

3.248
5.133

5.692
8.337


Sulfur
.196
.297
.378
.259
.369
.395
.278
.398
.440
.624
.898
.942
.292
.409
.430
.198
.277
.289
.163
.258
.272
.344
.503
.549

Sulfate
.015
.022
.028
.008
.011
.012
.008
.011
.012
.015
.022
.023
.000
.000
.000
.016
.022
.023
.007
.011
.012
.015
.022
.024

Pyritic
.058
.088
.112
.079
.112
.120
.077
.110
.122
.169
.244
.256
.073
.102
.108
.063
.089
.093
.064
.101
.107
.090
.131
.143

Organic
.123
.187
.238
.173
.246
.263
.193
.276
.3Q5
.439
.632
.663
.219
.307
.323
.119
.166
.174
.092
.146
.154
.239
' .350
.382
  Heating
value (Btu)
                                                                                                  6608
                                                                                                 10026
                                                                                                 12773

                                                                                                  8082
                                                                                                 11504
                                                                                                 12310
                                                                                                  7866
                                                                                                 11246
                                                                                                 12431

                                                                                                  7996
                                                                                                 11508
                                                                                                 12077
                                                                                                  8265
                                                                                                 11569
                                                                                                 12166

                                                                                                  8286
                                                                                                 11624
                                                                                                 12127

                                                                                                  7225
                                                                                                 11416
                                                                                                 12034
                                                                                                  7462
                                                                                                 10930
                                                                                                 11924
                                                                                                                                               D
                                                                                                                                               D
                                                                                                                                                                   D
                                                                                                                                                                   n
                                                                                                                                    D
                                                                                                                                    n
                                                                                                                                    o
                                                                                                                                                                   p
                                                                                                                                                                   >
 /A, as received; B, moisture free; C, moisture and ash free.
                                                                                                                                                                   10
                                                                                                                                                                   VO

-------
30
STRIPPABLE COAL, SOUTHEASTERN MONTANA
   In the Deer Creek coal deposit (PI. 2, 33) east of the
Tongue River Reservoir, the Anderson, Dietz No. 1, and
Dietz No. 2 coal beds are all separated by partings. Near
the Tongue River Reservoir, the parting between the
Anderson and Dietz No. 1 is about 20 feet but it increases
eastward to 60 feet. The parting between the Dietz No. 1
and  Dietz No. 2  ranges from 50 to 80 feet throughout
the area.

   In the Deer Creek coal field, the Anderson, Dietz No. 1,
and  Dietz  No. 2 coal beds contain  strippable reserves
over a large area, but in various parts of the field the
Anderson and Dietz No.  1 beds have burned, leaving re-
serves  only in the Dietz No. 2 coal bed.  The Anderson
coal reserves are in sec. 12, 13, 14, 22, and 23, T. 9 S.,
R. 40 E., and in sec. 2, 3, 4, 5, 6, 8, 9, 10, 14, 16, 17, and
18, T. 9 S., R. 41 E. The Anderson coal bed in this area
averages 20 feet in thickness. Where the  Anderson bed
has burned or has been  removed by erosion, the Dietz
No.  1  and  Dietz No. 2 coal beds still contain strippable
coal. The Dietz No. 1 coal extends throughout the area
except in sec. 36, T. 8 S., R. 40 E, and sec. 1 and 2, T. 9  S.,
R. 40 E. Only the Dietz No.  2 bed remains unburned
throughout the area. The principal reserves in the Dietz
No.  1  and  Dietz No. 2 coal beds include the west half of
sec.  1 and sec. 2, 12, 13, and 14, T.9S., R.40 E., and sec.
6, 7, and 8, T. 9 S., R. 41 E. The Dietz No. 1 and Dietz No. 2
coal beds are each about 1 8 feet thick.

   Additional strippable reserves are inferred along Corral
Creek in sec. 1 9, 20, 21, 22, 23, 27, 28, 29, 30, 31, and 32,
T. 8 S., R. 41  E. The deposit is limited by the burn at the
outcrop and by high ground to the southeast.

   The Roland coal bed is approximately  350 feet above
the  top of the Anderson coal bed and underlies the high
divides both  east and west of the Tongue River. In the
Roland (PI. 3) and Squirrel Creek (PI. 4) coal deposits,
the thickness of the Roland bed ranges from 6 to 14 feet.
The Smith coal bed is below the Roland  and about 182
feet above the Anderson bed, as shown in drill hole SH-
7022 in sec. 10, T. 9 S., R. 41 E.
                                i
                                •5
                                S
                                I
                                1
                                i
                                i
                                              \o
                                              00
                     vq
                     r^
                   oo
                   o\
                                                                  V0
                                      « q
                                      o •*
.£* O*
O „>•
tn «o
                                        \o
                                                     vo
                                               m
                                               
-------
                                       INDIVIDUAL DEPOSITS—KIRBY
                                                 31
   Bureau analyses of ash constituents are shown in Tables
6,8,10, and 12; these tables also include results reported
by the US. Geological Survey laboratories, Denver. Trace-
element analyses, shown in Tables 4 and 5, were reported
by the U.S. Geological Survey laboratories, Denver, (U.S.
Geological Survey Open-File Report, 1973). Analyses of
four core samples from the combined Anderson and Dietz
No. 1 coal beds reported that the Decker deposit showed
a calorific value of 10,250 Btu, fixed carbon ranging from
30 to 45%, volatile matter ranging from 30 to 37%, mois-
ture 15.60%, and ash 3.9% (Ayler, Smith, and Deutman,
1969, p.  17). Analyses of two core samples of the Dietz
No. 2 bed, which has an average thickness of 18.2 feet,
showed a calorific value of 9,600 Btu, fixed carbon 30 to
45%,  volatile matter 34 to 43%, moisture 21.0%, and ash
4.87%. All values are reported on the "as received" basis,
as determined by Pacific Power and Light Company, and
they are comparable with the results obtained under our
project.

                  COAL RESERVES

   The coal  reserves in the Decker area  are shown indi-
vidually by  coal deposit  on Table 2. Reserves in  the
Decker coal field (PI. 1) total 2,239,990,000 tons in  the
Anderson, Dietz No. 1, and Dietz No. 2 coal beds. Re-
serves in the Deer Creek coal field (PI. 2) total 495,650,000
tons,  reported as  410,470,000  tons  indicated  and
85,180,000 inferred. Reserves in the  Roland coal field
(PI. 3) total 218,040,000 tons, and in the Squirrel Creek
(PI. 4) coal deposit, 133,410,000 tons.

              KIRBY COAL DEPOSIT

                     LOCATION

   The Kirby coal deposit (PI. 5A, B, and C) lies in T. 6
and 7 S., R. 39 and 40 £., and in the narrow strip on the
eastern edge of T. 6 and 7 S., R. 38 E., that lies east of
the Crow Indian Reservation  boundary, Big Horn County.
The maps of the Kirby area show  strippable reserves in
the Anderson and Wall coal beds (PI. 5A), in the Dietz
coal bed  (PI. SB), and in the Canyon coal bed (PI. 5C).
The area is bounded on the north by the  Northern Chey-
enne Indian  Reservation boundary, on the west by the
Crow Indian Reservation boundary, and on the south by
the limit of strippable coal or the area where burning has
removed  the coal. The  eastern boundary is the eastern
side of the divide between the Tongue River and Rosebud
Creek or the area where burning has removed the coal.

         FIELD WORK AND MAP PREPARATION

   Extensive field work and  interpretation were required
on the Kirby area because of the structural complexity.
Drilling was begun during the 1969 field season, and addi-
tional holes were drilled during the 1970 field season. In
midwinter  1972-73, more holes were drilled to verify
some of the interpretations and to assist in the final prep-
aration of the maps. After the first drilling in 1969, prep-
aration of  a structure map was attempted, but the area
was more complex than had been  expected. In the sum-
mer of 1972, detailed field mapping on topographic maps
and black-and-white photos was completed for six 7&-
minute quadrangles extending from Rosebud Creek to
the Tongue River in the vicinity of Birney. Much of the
next whiter was spent interpreting this work and in form-
ulating the structure and overburden maps. Gulf Mineral
Resources  Company supplied colored aerial photos of
the area, and Pat McDonough of Billings provided logs of
drill holes in the Rosebud Creek area.

             PREVIOUS GEOLOGIC WORK

   The Kirby area was mapped and described in  a U.S.
Geological  Survey report on the northern extension of
the Sheridan coal field (Baker, 1929) and in a US. Bureau
of Mines report on the strippable coal in Montana (Ayler,
Smith, and Deutman, 1969).

                  LAND OWNERSHIP

   Most of the surface is privately owned, with the ex-
ception  of sec. 16 and 36 in each township, which are
owned by the State of Montana, and a small amount of
surface in T. 6 and 7 S., R.40 E., which is public domain.
Most of the coal, however, is owned by the Federal Gov-
ernment. The state owns the coal underlying its  tracts,
and some coal is owned in fee by individuals in the valley
bottom along Rosebud Creek.

         SURFACE FEATURES AND LAND USE

   The surface features within the area of the Kirby coal
deposit range from the rolling prairie on the high divide
between  the Tongue River and Rosebud  Creek to  the
deeply incised  valleys of Rosebud Creek  and its steep
tributaries that are bordered by rugged bluffs. Also prom-
inent is the rugged topography on the east side  of the
divide where tributaries of the Tongue River such as Can-
yon Creek, Fourmile Creek, and Post Creek are deeply in-
cised. Ponderosa  pine grows  on clinkered areas along
the steep valley sides. Rosebud Creek flows north and
joins the Yellowstone near Rosebud.

   The principal  land use is  livestock grazing. Hay is
raised along the narrow valleys of Rosebud Creek and
some of  its tributaries of the Tongue River on the east
side of the divide. On part of the high divide area be-

-------
32
                 STRIP?ABLE COAL, SOUTHEASTERN MONTANA
                    Table 13.-Reserves, overburden, overburden ratio, acres, and tons/acre, Kirby coal deposit
                                                   ANDERSON BED
  Thickness of
 overburden, ft.
Indicated reserves,
   million tons
     Overburden,
    million cu. yd.
   Overburden ratio,
    cubic yards/ton
                  Acres
       Tons/acre
      Oto 50
     SO to 100
    100 to ISO
               Total
                    Total
         73.87
        261.05
        425.34
        760.26
         1.48
         3.15
         5.08
Average  3.51
                                                                             Total
                  1,387.7               35,922.7
                  2,157.8               38,414.1
                  2.109.8               39.709.8
                  5,655.3      Average   38,285.2
                                                      DIETZ BED
Oto 50
50 to 100
100 to 150
150 to 200
200 to 250
Total
180.00
243.95
248.02
80.00
82.38
834.35
                                              232.93
                                              681.78
                                             1.097.66
                                              290.74
                                              379.58
                                      Total  2,682.69
                                        Average
                              1.29
                              2.79
                              4.43
                              3.63
                              4.61
                              3.22
                  Total
                  4,371.2
                  5,632.0
                  5,440.0
                  1,030.4
                  1.043.2
                 17,516.8
Average
41,178.6
43,314.9
45,591.9
77,639.8
78.968.6
47,630.9
                                                    CANYON BED
      Oto 50
    50 to 100
   100 to 150
   150 to 200
               Total
     19.56
     58.31
     78.31
      2.35
    158.53
Total
Average
1.42
3.10
5.11
7.23
3.95
                                                                             Total
                                                                               Average
         37,278.44
         38,998.12
         39,423.07
         38.971.80
         38,983.42
                                                      WALL BED
      Oto  50
     50 to 100
    100 to 150
    ISO to 200
    200 to 250
               Total
                    Total
         38.0
        112.69
        213.65
        428.16
        628.16
      1,420.66
         0.67
         1.52
         2.54
         3.54
         4.56
Average  2.99
                                                                             Total
                              Average
         79,647.0
         79,647.9
         79,469.0
         79,646.8
         79.523.9
         79,579.7

-------
                                       INDIVIDUAL DEPOSITS-KIRBY
                                                                                                         33
tween Rosebud Creek and the Tongue River, grain is cul-
tivated by dry-land fanning.

   The area in sec. 16,17,18,19,20, 21, and 22, T. 7 S.,
R. 39 £., has historic value as the site of the battle be-
tween Captain Crook and the Sioux on June 17, 1876.

               GEOLOGIC STRUCTURE

   The relative  complexity of the geologic structure in
the Kirby area  is the result of numerous  faults, which
have caused local reversal in the generally southeast dip
of the Tongue River beds.

   The Kirby coal deposit seems to occupy a zone where
the trend of lineations changes from northwest to north-
south and east-west. Along the valleys of Canyon Creek,
Fourmile Creek, and Post Creek in T. 6 and  7 S., R. 40 E.,
the northwest lineations are  obvious. In  the Rosebud
Creek tributaries, north-south and east-west lineations are
visible. Rosebud Creek flows northward, and in the south-
western part of T. 7 S., R. 39 E., it seems to be controlled
by this structural pattern.

   The faults  in the area, although difficult to see except
in local small areas, are depicted graphically on Plate 33,
cross section  SC-K, as  normal tensional features. They
have been  projected on  the  basis of surface mapping,
color-photo interpretation, and drill-hole data. Displace-
ment of most of the faults ranges from only a few feet to
about 200 feet. In the northeast corner of T. 7 S., R. 39 E.,
a graben has  dropped the Tongue River strata, as illus-
trated on Plate 5A, which shows the Anderson coal bed.

                    COAL BEDS

   The strippable coal beds in the Kirby area are in the
upper part of the Tongue River Member and include,
from top to bottom, the Anderson, Dietz No. 1 and No.
2, the Canyon,  and the Wall coal beds, all of which are
correlated with beds of the same name in the  Decker
area. The Smith and Cook coal beds have also been
mapped in the area. The Smith bed, above the Anderson
bed, is 9 feet thick, as  measured in drill hole SH-731A,
in the NWtt sec.  27,- T. 7 S., R. 39  E. The Cook bed
forms two  benches lying between the Canyon and Wall
coal beds. Thickness of the upper bench reaches 11 feet;
the lower bench ranges from a trace to 3 feet.

   The Anderson coal bed contains large  strippable re-
serves. The bed is thickest near the Big Bend of the Rose-
bud, sec. 21 and 22, T.  7 S., R. 39 E., where it is 30 feet
thick. It thins northeastward to 8 feet as in drill hole SH-
41 in sec. 26, T. 6 S., R. 39 E. In drill hole SH-736, the
Anderson coal bed has a thickness of 26 feet, and a lower
bench 4 feet thick lies 3  feet below the thick end. The
combined Dietz No. 1  and No. 2  is only  10 feet below
the base of the lower bench of the Anderson coal bed in
this area. The Anderson and Dietz beds split northward,
as shown on the cross section SC-K, Plate 33.

   The Dietz No. 1 and No. 2 beds are combined in the
southwestern part of the mapped area and are almost SO
feet thick, but they thin and split northeastward. In the
north part of the area (PI. 5B), only the reserves in the
Dietz No. 1  bed are included, although the Dietz No. 2
bed may contain additional reserves.

   Because the Canyon coal bed crops out on the  steep
sides of Rosebud Creek valley, it does not contain nearly
as large  strippable reserves as the Anderson or the Dietz
coal beds. The thickness trend exhibited by the Anderson
and Dietz No. 1 and No.  2 coal beds is not followed by
the Canyon  coal bed. It is thickest in the northernmost
part of the area, as in drill hole SH-36 in sec. 16, T. 6 S.,
R. 39 E., where it is 25 feet thick. It thins southward and
is 16 feet thick in sec. 9, T. 7 S., R. 39 E.

  The Wall coal bed is below the floor  and along the
sides of Rosebud Creek valley and along the floor of sev-
eral tributary valleys in T. 6 S.,  R. 39 E. Steep-sided
clinker-capped ridges along Rosebud Creek preclude  strip-
ping of the Wall coal bed in any very large areas. The coal
bed is as much as 54 feet thick in the Kirby deposit, and
the thickness averages nearly 50 feet in a large area ex-
tending  into T. 7 S., R  39 and 40 E. Farther east in drill
hole SH-50 in sec. 1, T. 7  S., R. 40 E., the  Wall bed is 60
feet thick.

                  COAL QUALITY

  Samples of the Anderson, Dietz No. 1, Dietz No. 2,
and Canyon coal beds were  obtained for  analysis. Ana-
lytical results are shown in Tables 14 and 15.

                  COAL RESERVES

  Strippable coal reserves in the Kirby  coal deposit have
been mapped in the Anderson, combined Dietz No. 1 and
No. 2, Canyon, and Wall coal beds. Indicated reserves for
these coal beds are shown  on Table 13.

  Total reserves are: Anderson coal bed, 216,520,000
tons; Dietz No. 1 and No.  2 beds, 834,350,000 tons; Can-
yon bed, 158,530,000 tons; Wall coal bed, 473,690,000
tons. The total strippable reserves are 1,683,090,000 tons.

-------
Table 14.-Proximate analysis, forms of sulfur, and heating value, Kirby coal deposit.
                                     'Ximate. %
Form of sulfur. %
Drill hole
and location
SH-31
7S 40E SB
ACAD






SH-35
6S 39E S14
BBCA
SH-36
6S39ES16
BADC






SH-37
7S 39E S24
BBCB






SH-38
7S39ES11
DACD





SH-39
7S 39E S10
ADBB
SHAl
6S 39E S26
CADD
Depth
sampled

35 to
45ft.

96 to
106ft.

106 to
112ft.

89 to
99ft

104 to
113ft.

113 to
123 ft.

123 to
130ft.

40 to
49ft.

49 to
58ft.

S8V4to
60ft.

73 to
81ft.

108 to
117ft.

117 to
126 ft.

70 to
74ft.

92 to
100ft.
Lab.
number


83


84


85


87

77


78


79


80


82


81


88


101

102


108

109
Coal Form of
bed analysis
Anderson A
B
C
A
Dietz B
C
A
B
C
Dietz A
B
C
Canyon A
B
C
A
B
C
A
B
C
Anderson A
B
C
A
B
C
A
B
C
Anderson A
B
C
A
B
C
A
B
C
Dietz No. 1 A
B
C
Dietz No. 1 A
B
C
i
/ Moisture
29.490


28.310


29.800


28.230


27.170

27.770


16.390


27.040


25.550


26.630


31570


27.630


22.090

24.010


27.870

Volatile
matter
26.757
37.948
42.885
28.679
40.005
42.949
28.002
39.889
41.752
29.772
41.483
45.743
26.897
36.932
38.653
31.430
43.513
45.699
30.584
36.580
41.979
29.274
40.123
42.512
29.861
40.109
42.437
30.934
42.162
44.515
28.973
42.339
45.098
31.270
43.209
45.183
33.494
42.990
45.539
26.079
34.319
36.467
31.853
44.160
47.419
Vixed
carbon
35.636
50.541
57.115
38.096
53.140
57.051
39.066
55.649
58.248
35.313
49.203
54.257
42.690
58.616
61.347
37.345
51.703
54.301
42.271
50.558
58.021
39.587
54.258
57.488
40.504
54.405
57.563
38.558
52.552
55.485
35.271
51.544
54.902
37.938
52.422
54.817
40.056
ititt
45.434
59.790
63.533
35.320
48.967
52.581

Ash
8.116
11.511

4.914
6.855

3.132
4.462

6.684
9.313

3.243
4.453
3.455
4.783

10.754
12.863

4.100
5.619

4.084
5.486

3.878
5.286

4.186
6.117

3.162
4.369

4.360
5.596
4.477
5.891

4.957
6.872

Sulfur
.650
.922
1.042
.288
.402
.431
.251
.357
.374
.277
.387
.426
.224
.307
.321
.216
.300
.315
.280
.335
.384
.262
.359
.381
.212
.285
.301
.432
.589
.621
.368
.537
J72
.185
.256
.267
.326
.419
.444
2.375
3.126
3.322
.314
.436
.468

Sulfate
.064
.091
.103
.033
.046
.049
.008
.012
.012
.000
.000
.000
.026
.035
.037
.024
.033
.035
.019
.022
.026
.042
.058
.061
.017
.023
.024
.042
.057
.060
.023
.034
.037
.000
.000
.000
.009
.012
.012
.377
.497
.528
.033
.046
.049

Pyritic
.072
.102
.116
.049
.069
.074
.024
.035
.036
.067
.094
.103
.052
.071
.074
.040
.055
.058
.075
.089
.102
.042
.058
.061
.051
.068
.072
.066
.091
.096
.078
.114
.122
.042
.058
.061
.045
.058
.062
.772
1.016
1.079
.058
.080
.086

Organic
.514
.729
.823
.206
.287
.308
.219
.311
.326
.210
.293
.323
.146
.201
.210
.152
.211
.221
.187
.223
.256
.178
.243
.258
.144
.193
.205
.324
.441
.466
.266
.389
.414
.143
.198
.207
.272
.349
.370
1.226
1.614
1.715
.223
.310
.333
Heating
value (Btu)
7277
10321
11664
8275
11543
12393
8308
11834
12387
8383
11680
12879
9113
12513
13096
8446
11693
12281
8808
10534
12089
8391
11500
12185
8637
11601
12275
8491
11573
12219
7708
11265
11999
8422
11637
12169
8864
11378
12052
7467
9826
10441
8074
11194
12020










"
#
|
to

n
o
o

•
en
9
S
09

SO

z
i
>













-------
SH-56
7SR39ES18
DDCD
SH-107
7S R40E S30
BAAA
SH-722
6S R39E S35
OCBD
SH-7012
7S R40E S29
CDBC
 72 to
 82ft.

 82 to
 90ft.

 90 to
 97ft.
 35 to
 43ft.

 90 to
 94ft.

152 to
162 ft.

162 to
172 ft.
Ill to
120 ft.

120 to
130ft.
 98 to
107 ft.

107 to
116ft.

116 to
126 ft.

129 to
139 ft.

139 to
146 ft.
                      Anderson
131


132


133



143


144


145


146



481


482



174


175


176


177


178
Anderson



Dietz No. 1


Dietz No. 2




Dietz No. 1





Dietz No. 1
A
B
C
A
B
C
A
B
C

A
B
C
A
B
C
A
B
C
A
B
C

A
B
C
A
B
C

A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
27.200


28.400


25.910


22.370


21.500


24.910


22.040


27.930


31.140


26.220


27.150


28.720


28.430


25.340


30.133
41.392
43.962
30.210
42.193
44.205
31.378
42.351
45.052
33.406
43.032
45.006
33.440
42.598
44.815
30.216
40.240
42.271
32.262
41.383
43.462
30.994
43.005
45.798
28.776
41.790
43.816
29.110
39.455
47.027
30.712
42.158
45.160
31.362
43.999
46.092
28.344
39.603
46.840
29.399
39.377
48.516
38.411
52.763
56.038
38.130
53.255
55.795
38.270
51.653
54.948
40.821
52.584
54.994
41.178
52.456
55.185
41.266
54.956
57.729
41.968
53.833
56.538
36.682
50.897
54.202
36.899
53.586
56.184
32.790
44.443
52.973
37.295
51.194
54.840
36.681
51.460
53.908
32.168
44.946
53.160
31.198
41.786
51.484
4.255
5.845

3.260
4.553

4.443
5.996

3.403
4.384

3.882
4.946

3.608
4.805

3.729
4.784

4.395
6.098

3.184
4.624

11.880
16.102

4.843
6.648

3.237
4.541

11.058
15.451

14.064
18.837

.273
.375
.398
.229
.320
.336
.389
.524
.558
.209
.269
.281
.222
.283
.298
.201
.268
.281
.234
.300
.315
.246
.342
.364
.346
.503
.527
1.520
2.061
2.456
.360
.494
.529
.229
.322
.337
.398
.556
.657
1.591
2.131
2.626
.016
.022
.023
.000
.000
.000
.017
.023
.024
.018
.023
.024
.027
.034
.036
.017
.023
.024
.018
.023
.024
.015
.021
.023
.015
.021
.022
.042
.056
.067
.017
.023
.025
.016
.023
.024
.016
.023
.027
.040
.054
.066
.024
.033
.035
.040
.055
.058
.051
.068
.073
.027
.035
.037
.044
.057
.060
.052
.070
.073
.054
.069
.073
.038
.053
.057
.059
.086
.090
.822
1.115
1.329
.075
.103
.111
.057
.080
.084
.089
.125
.148
.871
1.167
1.438
.233
.320
.340
.190
.265
.278
.321
.433
.461
.163
.210
.220
.151
.192
.202
.131
.174
.183
.162
.207
.218
.192
.267
.284
.273
.396
.415
.656
.890
1.060
.268
.367
.394
.156
.218
.229
.292
.408
.483
.680
.910
1.122
8426
11574
12292
8376
11699
12257
8527
11509
12244
8493
10940
11441
9073
11558
12160
8950
11919
12521
9301
11931
12530
8552
11867
12637
8226
11946
12525
8033
10887
12977
8952
12288
13163
9502
13331
13965
7488
10463
12375
8049
10781
13283














2
0




r
D
pi

o
Cfl

3

a
w
•<












 /A, as received; B, moisture free; C, moisture and ash free.

-------
Ttble 15.-Major uh constituents, Kirby coal deposit.
u>
L/IIU I1UIC
and location
SH-31
7S 40E S8
ACAD
SH-35
6S 39E S14
BBCA
SH-36
6S39ES16
BADC
SH-37
7S 39E S24
BBCB

SH-38
7S39ES11
DACD

SH-39
7S 39E S10
ADBB

SH-41
6S 39E S26
CADD

SH-56
7S 39E S18
DDCD
SH-107
7S 40E S30
BAAA




SH-7012
7S 40E S29
CDBC
M|IU1
sampled

96 to
112ft.

89 to
99ft.

104 to
130ft.

40 to
60ft.


108 to
126ft.


70 to
74ft.


92 to
100ft.


72 to
97ft.

35 to
43ft.
90 to
94ft.
152 to
172 ft.

98 to
146 ft.
UIU.
sample


84-85


87


77-79


80-82



101-102



108



109



131-133


143

144

145-146


174-178
V'UOA
bed
Dietz No. 1


Dietz No. 1


Canyon


Anderson



Anderson



Dietz No. 1



Dietz No. 1



Anderson


Anderson


Dietz No. 1

Dietz No. 2

Dietz No. 1


AljOj
9.6


16.1


12.4


10.2



14.8



20.5



11.2



10.6


17.8


12.2

17.6

18.2


CaO
35.4


14.5


18.8


21.3



8.1



6.0



19.6



23.3


25.0


18.5

23.4

7.8


FeaOa
3.5


4.0


5.5


7.3



4.4



12.6



9.9



4.7


3.2


3.3

2.6

6.7


KjO
.2


.8


1.6


.3



2.0



.7



.3



.3


.3


.2

.3

1.9


MgO
8.1


5.5


6.6


5.3



3.0



2.7



S.I



5.6


8.5


3.9

7.2

4.3


NaaO
.4


.3


1.5


7.6



1.8



1.8



7.4



6.3


4.0


8.7

1.5

1.6


pao,
.7


1.2.


.3


.4



.2 *



.3



.5



.5


1.5


.6

.3

.5


SiOa
31.0


43.1


40.3


33.6



56.2



48.3



23.9



32.8


19.2


35.9

28.1

47.3


S0a
11.5


7.7


9.9


13.3



6.3



5.6



13.0



12.3


15.6


9.0

13.7

9.5


Ti02
1.6


1.1


.6


1.0



.7



.8



.2



1.1


.8


1.0

1.1

1.1


Total
102.0


94.3


97.5


100.3



97.5



99.3



91.1



97.5


95.9


93.3

95.8

98.9










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-------
                                  INDIVIDUAL DEPOSITS—CANYON CREEK

             Table 16.-Reserves, overburden, overburden ratio, acres, and tons/acre, Canyon Creek coal deport.
                                                                                     37
                                              WALL BED
Thickness of
overburden, ft.
Oto 50
SO to 100
100 to 150
150 to 200
200 to 250

Indicated re:
million toi
246.73
450.64
483.46
386.52
31650
Total 1,884.25
                                Total
                                     Overburden,
                                    million cu. yd.
                    204.44
                    741.88
                   1,273.54
                   1,209.72
                   1.212.71
                   4,642.29
                                  Overburden ratio,
                                  cubic yards/ton         Acres
                            .82             3,833.6
                           1.64             6,112.0
                           2.63             6,291.2
                           3.12             4,288.0
                           3.82             3.334.4
                   Average  2.46     Total   23,859.2
                                   Average
                                                             Tons/acre
                           64,359.9
                           73,730.4
                           76,849.5
                           90,139.9
                           95.039.6
                           78,974.3
                                        BREWSTER-ARNOLD BED
  Oto  50
 50 to 100
 100 to 150
           Total
 4.69
30.38
30.79
65.86
Total
        1.67
        3.79
        6.32
Average  4.82
Total
  147.2             31,861.4
  953.6             31,858.2
  966.4             31.860.5
2,067.2     Average  31,859.5
          CANYON CREEK COAL DEPOSIT

                     LOCATION

   The Canyon Creek coal deposit is in portions of T. 5,6,
and 7  S., R. 40, 41, and 42 E., Big Horn and Rosebud
Counties (PI. 6). The area is limited on the east by the
clinker of the Wall coal bed and by Tongue River, on the
north by the boundary of the Northern Cheyenne Indian
Reservation, and on the west by the increasing overbur-
den on the Wall coal bed.

         FIELD WORK AND MAP PREPARATION

   The largest part of the field work in the Canyon Creek
coal  deposit was completed in  1969.  Additional holes
were drilled in 1970 along Fourmile  Creek and Cook
Creek.  Coal outcrops, burn lines,  clinkered areas, and
faults were mapped in  1972 on aerial photos and 7%-
minute topographic quadrangle maps.

             PREVIOUS GEOLOGIC WORK

   The Canyon Creek area was described in a U S. Geo-
logical  Survey report (Baker, 1929).

                 LAND OWNERSHIP

   The Federal  Government has large contiguous blocks
of land within the area, and it is the largest single owner
                                    of surface. Private ownership is next, followed by the
                                    State of Montana, which owns each sec. 16 and 36, and
                                    then by the Burlington Northern, Inc., which owns some
                                    alternate sections along Cook Creek in T. S S., R. 41 and
                                    42 E.


                                       The Federal Government also owns the largest share
                                    of the coal in the area, but the next largest owner is the
                                    State of Montana (all sec. 16 and 36), followed by Bur-
                                    lington Northern, Inc. Private individuals own small tracts
                                    along Cook Creek and along some other tributaries of
                                    the Tongue River.
                                             SURFACE FEATURES AND LAND USE


                                       The topography  of the area ranges from rugged to
                                    rolling. The rugged areas are capped by clinker along the
                                    sides of the valleys of Tongue River and its tributaries.
                                    Rolling topography characterizes the divides at the heads
                                    of the numerous northwest-trending valleys. Ponderosa
                                    pine grows on the clinkered areas along the steep valley
                                    sides.

                                       The principal land use in the area is livestock grazing.
                                    Although virtually none of the  area is cultivated, some
                                    hay is raised in meadows along the valley of the Tongue
                                    River.

-------
                                          Tible 17.-Proximate analysis, fomu of sulfur, and heating ralne, Canyon Creek coal deport.
                                                                                                                                                         00
  Drill hole
 and location
 SH-42 LJ
 7S 42E S9
pABDA

 SrMS
 6S41ES21
 CDDA
 SH-46
 6S41ES16
 CABC
 SH-49
 6S 40E S24
 CCCA
 SH-50
 7S 40E SI
 BDDD
Depth
sampled
35 to
46ft.
57 to
66ft.
66 to
75ft.
75 to
84ft
84 to
94ft.
94 to
104ft.
40 to
50ft.
50 to
60ft.
60 to
70ft.
70 to
80ft.
80 to
89ft.
40 to
50ft.
50 to
59ft.
59 to
65ft.
65 to
74ft.
74 to
79ft.
200 to
209 ft.
Lab.
number
89
112
113
114
115
116
118
119
120
121
122
103
104
105
106
107
91
Coal
bed
Wall
Wall




Wall




Wall




Wall
Form of
analysis
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
Proximate . %
i
V Moisture
16.840


24.370


24.030


23.030


25.970


26.000


23.380


26.730


25.290


25.510


26.370


23500


23.690


23.300


24.940


25.280


26.090


Volatile
matter
34.287
41.230
44.147
31.963
42.262
44.374
29.685
39.074
41.715
31.108
40.416
42.282
28.861
38.985
42.773
28.734
38.830
41.373
31.648
41.305
44.802
30.167
41.172
43.397
29.761
39.836
41.724
29.001
38.933
41.944
28.352
38.507
46.444
29.766
38.910
41.713
30.925
40.525
42.678
31.086
40.529
43.065
31.924
42.532
44.125
30.250
40.485
42.619
28.050
37.951
40.199
fixed
carbon
43.378
52.163
55.853
40.068
52.979
55.626
41.476
54.595
58.285
42.465
55.171
57.718
38.613
52.159
57.227
40.716
55.022
58.627
38.991
50.888
55.198
39.347
53.701
56.603
41.567
55.638
58.276
40.142
53.889
58.056
32.693
44.402
53.556
41592
54.369
58.287
41.536
54.431
57.322
41.098
53.583
56.935
40.426
53.858
55.875
40.728
54.507
57.381
41.727
56.457
59.801

Ash
5.495
6.608

3.599
4.759

4.810
6.331

3.397
4.413

6556
8.856

4549
6.148

5.982
7.807

3.756
5.127

3.382
4527

5.347
7.178

12584
17.091

5.142
6.721

3.849
5.044

4516
5.888

2.710
3.610

3.742
5.008

4.133
5592


Sulfur
.472
.568
.608
.119
.157
.165
.129
.170
.182
.159
.207
.216
.370
.500
.549
.710
.960
1.023
.290
.378
.410
.216
.294
.310
.156
.208
.218
.411
.552
595
1.064
1.445
1.743
.225
.295
.316
.208
.273
.287
.173
.226
.240
.147
.195
.203
.153
.205
.216
.356
.481
.510
Form (

Sulfate
.045
.055
.058
.025
.034
.035
.026
.034
.036
.018
.023
.024
.069
.093
.102
.076
.103
.110
.026
.034
.037
.025
.034
.036
.035
.046
.049
.061
.082
.089
.194
.264
.318
.069
.091
.097
.052
.068
.072
.035
.045
.048
.000
.000
.000
.017
.023
.024
.034
.046
.049
iffvUfui %

Pyritic
.145
.175
.187
.042
.056
.059
.043
.057
.061
.044
.057
.060
.078
.105
.115
.093
.126
.134
.061
.080
.087
.041
.057
.060
.052
.069
.073
.123
.164
.177
.270
.367
.443
.078
.102
.109
.052
.068
.072
.069
.090
.096
.043
.057
.060
.051
.068
.072
.068
.092
.097


Organic
.282
.339
.363
.051
.067
.071
.060
.079
.085
.097
.126
.132
.224
.303
.332
541
.731
.779
.202
.264
.286
.149
.204
.215
.069
.093
.097
.228
.305
.329
.600
.814
.982
.078
.102
.109
.104
.136
.144
.069
.090
.096
.104
.138
.143
.085
.114
.120
.254
.344
.364
Heating
value (Btu)
9675
11634
12457
8868
11726
12312
8955
11788
12585
9386
12194
12757
8545
11542
12663
8739
11809
12582
8892
11605
12588
8606
11746
12381
9045
12107
12681
8735
11727
12634
7637
10373
12511
9303
12161
13038
9480
12423
13083
9030
11773
12510
9316
12411
12876
8738
11695
12311
9043
12236
12960











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-------
SH-50
7S 40E SI
BDDD
SH-110
5S41ES33
CBBB
SH-121
6S40ES12
AADD
SH-707 V
7S41ES33
CCDC
209 to
218 ft.
218 to
227 ft.
227 to
236ft.
236 to
245 ft.
245 to
254 ft.
254 to
260 ft.
150 to
159 ft.
159 to
163 ft.
130 to
140 ft.
145 to
155 ft.
155to
165 ft.
165 to
173ft
73 to
83ft.
83 to
92ft.
92 to
103 ft.
103 to
113ft.
113to
123ft.
92
93
94
95
96
97
147
148
154
155
156
157
165
166
167
168
169
Wall
Wall
Wall
Wall
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

A
B
C
A
B


A
B
C
A
B
C
A
B
C
A
B
C

A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
26.640


24.800


24.400


21.600


25.600


26.400


22.360


20.220


21.520


19.940


26.160


25.990


23.390


24.660


24.490


23.310


23.600


27.980
38.141
39.981
29.682
39.471
43.026
36.671
48.507
51.342
36.350
46.365
48.846
28.547
38.370
42.608
28.943
39.325
41.460
30.858
39.745
42.948
33.868
42.452
45.366
30.227
38.516
42.931
31.891
39.833
42.834
29.526
39.986
41.737
28.990
39.171
42.059
29.799
38.897
41.013
23.325
30.960
33.142
29.455
39.008
41.063
30.831
40.203
42.010
29.179
38.193
40.652
42.004
57.257
60.019
39.303
52.265
56.974
34.755
45.972
48.658
38.068
48.556
51.154
38.452
51.683
57.392
40.866
55.524
58.540
40.991
52.797
57.052
40.788
51.125
54.634
40.182
51.201
57.069
42.562
53.162
57.166
41.217
55.819
58.263
39.938
53.963
57.941
42.858
55.944
58.987
47.055
62.457
66.858
42.275
55.987
58.937
42.559
55.495
57.990
42.599
55.758
59.348
3J76
4.602

6.215
8.264

4.174
5.521

3.982
5.079

7.401
9.947

3.791
5.151

5.790
7.458

5.124
6.423

8.070
10.283

5.608
7.004

3.098
4.195

5.082
6.866

3.953
5.160

4.960
6.583

3.780
5.006

3.299
4.302

4.622
6.049

.226
.308
.322
.227
301
.328
.227
.301
.318
.370
.472
.498
.208
.280
.310
.446
.606
.639
.380
.489
.528
.189
J237
.254
1.115
1.421
1.584
.167
.208
.224
.128
.173
.181
.236
.319
.342
.443
.578
.610
.236
.313
.335
.261
.346
.364
.250
.327
.341
.360
.471
.502
.025
.034
.036
.016
.022
.023
.024
.032
.034
.017
.021
.023
.024
.032
.036
.016
.022
.023
.062
.080
.086
.018
.023
.024
.195
.248
.276
.018
.022
.024

023
!024
.034
.046
.049
.017
.022
.023
.025
.034
.036
.025
.033
.035
.017
.023
.024
.017
.022
.024
.075
.103
.107
.065
.086
.094
.057
.075
.080
.059
.075
.079
.080
.108
.119
.072
.097
.103

.088
.114
.123
.045
.057
.060

.513
.654
.729
.044
.055
.059
.034
.046
.048
.067
.091
.098

.111
.145
.152
.076
.101
.108
.093
.123
.129
.086
.113
.118
.103
.135
.143
.125
.171
.179
.146
.194
.211
.146
.193
.205
.295
.376
.396
.104
.140
.155
.358
.487
.513

.229
.296
.319
.126
.158
.169

.407
.519
.578
.105
.132
.141
.077
.104
.109
.135
.182
.196

.315
.411
.434
.135
.179
.191
.143
.190
.200
.147
.191
.200
.240
.314
.334
9191
12529
13134
9175
12201
13300
9419
12459
13187
8590
10957
11543
8587
11541
12816
9062
12313
12981
8972
11556
12488
9331
11696
12499
8725
11117
12392
8996
11236
12083
8940
12107
12637
8764
11841
12714
9556
12474
13153
9284
12323
13191
9425
12482
13139
9724
12679
13249
10079
13192
14041















5
o

o
c
c


o
CO
1


o

o
JO
P)
w















 /A, as received; B, moisture free; C, moisture and ash free.

 /Not shown on map.
                                                                                                                         ui

-------
                                                                     Table 17 (Continued).
  Drillhole
 and location
 SH-707
 7S41ES33
 CCDC

 SH-7013
 7S41ES21
 CACC
                                                                               jximate. %
Form of sulfur. %
SH-7057
5S 42E S28
DCDC
SH-47
6S 40E S3
ACBA
SH-48
6S40ES16
AAAA
Depth
sampled

123 to
128ft.

84 to
94ft.

94 to
103ft.

103 to
108ft.

108 to
115ft.

115 to
124ft.

124 to
132ft.

132 to
136 ft.

102 to
110ft.

110 to
118ft.

118 to
122 ft.

55 to
60ft.

60 to
70ft.

70 to
80ft.

80 to
90ft.

48 to
58 ft.

58 to
68ft.

68 to
78ft.
Lab.
number


170


179


180


181


182


183


184


185


266


267


268


123


124


125


126


127


128


129
Coal Form of
bed analysis
Wall A
B
C
Wall A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
Brewster- A
Arnold B
C
A
B
C
A
B
C
Canyon A
B
C
A
B
C
A
B
C
A
B
C
Canyon A
B
C
A
B
C
A
B
C
i
/ Moisture
24.450


25.670


25.280


24.840


24.160


26.220


27.660


25.870


24.900


26.650


26.790


28.400


28.800


30.400


25.600


22.120


26.060


26.440


Volatile
matter
29.561
39.128
41.152
32.125
43.219
46.430
30.837
41.270
43.232
31.678
42.148
44.804
33.582
44.280
46.067
29.188
39.560
40.967
32.402
44.792
47.245
32.937
44.431
46.048
27.954
37.222
44.673
28.651
39.060
42.954
39.726
54.263
56.984
28.872
40.324
44.520
29.492
41.422
43.722
27.308
39.236
41.676
21.019
28.252
48.638
30.181
38.753
42.040
28.185
38.118
39.779
23.731
32.261
42.234
Fixed
carbon
42.273
55.953
58.848
37.065
49.865
53.570
40.492
54.191
56.768
39.027
51.925
55.196
39.317
51.841
53.933

57 007
59i033
36.182
50.017
52.755
38.590
52.057
53.952
34.621
46.100
55.327
38.050
51.875
57.046
29.988
40.962
43.016
35.980
50.252
55.480
37.962
53.318
56.278
38.216
54.909
58.324
22.197
29.834
51.362
41.610
53.428
57.960
42.669
57.708
60.221
32.458
44.125
57.766

Ash
3.716
4.919

5.141
6.916

3.391
4.539

4.455
5.927

2.941
3.878

2.533
3.433

3.756
5.192

2.603
3.512

12.525
16.678

6.649
9.065

3.496
4.775

6.747
9.424

3.745
5.260

4.075
5.855

31.184
41.914

6.090
7.819

3.086
4.174

17.371
23.615


Sulfur
.422
.559
.588
.352
.474
.509
.187
.250
.262
.181
.241
.256
.173
.228
.237
.144
.195
.202
.264
.365
.384
.251
.339
.352
.553
.737
.884
.291
.397
.437
.357
.488
.512
.651
.909
1.004
.298
.418
.441
.337
.484
.514
3.242
4.357
7.501
.188
.241
.261
.213
.288
.301
.575
.782
1.024

Sulfate
.017
.022
.024
.016
.022
.023
.008
.011
.011
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000

.000
.017
.023
.027
.016
.022
.024
.017
.023
.024
.047
.066
.073
.039
.055
.058
.031
.044
.047
.275
.369
.636
.036
.046
.050
.026
.035
.036
.058
.079
.104

Pyritic
.068
.089
.094
.064
.086
.093
.049
.065
.068
.033
.044
.047
.033
.043
.045
.032
.043
.045
.032
.044
.047
.041
.055
.057
.145
.193
.231
.024
.033
.036
.043
.058
.061
.063
.088
.097
.047
.066
.070
.069
.099
.105
2.213
2.975
5.122
.054
.069
.075
.051
.069
.072
.283
.385
.504

Organic
.338
.447
.470
.272
.366
.393
.130
.174
.182
.148
.197
.209
.140
.185
.192
.112
.152
.157
.232
.320
.338
.211
.284
.295
.392
.522
.626
.251
.342
.376
.298
.407
.427
.541
.756
.835
.212
.297
.314
.237
.341
.362
.753
1.013
1.744
.098
.126
.137
.136
.184
.193
.233
.317
.415
Heating
value (Btu)
9316
12331
12969
8910
11988
12878
9206
12320
12906
9153
12177
12945
9514
12544
13050
9251
12538
12984
8953
12376
13054
9566
12904
13373
7979
10625
12751
8494
11580
12735
8859
12100
12707
8006
11181
12345
7759
10897
11502
8209
11795
12529
8719
11719
20174
8914
11446
12417
8776
11869
12386
6958
9458
12382












v>
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M

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W
O

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 /A, as received; B, moisture free; C, moisture and ash free.

-------
Table 18.-M«jor ash constituents, Canyon Creek coal deposit.
Drillhole
and location
SIM2
7S 42E S9
ABDA
SH-*5
6S41ES21
CDDA
SH-46
6S 41E S16
CABC
SH-49
6S 40E S24
CCCA
SH-50
7S 40E SI
BDDD


SH-110
5S41ES33
CBBB

SH-121
6S 40E S12
AADD

SH-707
7S41ES33
CCDC
SH-7013
7S41ES21
CACC
SH-7057
5S 42E S28
DCDC
SFM7
6S 40E S3
ACBA
SH48
6S 40E S16
AAAA
Depth
sampled

'35 to
46ft.

57 to
104 ft.

40 to
89ft.

40 to
79ft.

200 to
260 ft.



150 to
163 ft.


130 to
173 ft.


73 to
128 ft.

84 to
136 ft.

102 to
122ft.

55 to
90ft.

48 to
78ft.
Lab.
sample


89


112-116


118-122


103-107


91-97




147-148



154-157



165-170


179-185


266-268


123-126


127-129
Coal
bed
Wall


Wall


Wall


Wall


Wall




Wall



Wall



Wall


Wall


Brewster-
Amold

Canyon


Canyon



A1203
15.3


16.6


12.3


15.0


17.6




13.7



13.8



15.2


15.9


24.9


12.3


12.8



CaO
11.9


9.2


16.1


18.0


14.0




18.4



10.8



15.8


15.1


7.4


18.5


18.6



FejOj KjO
4.4 1.2


10.9 .9


4.6 .3


4.0 .3


3.7 .4




4.9 .2



6.8 .7



4.4 .3


4.5 .5


2.9 .4


4.6 .5


3.9 .5



MgO
8.8


3.4


4.3


10.0


2.2




6.6



6.1



6.1


2.1


2.0


5.2


5.9


consume
NajO
3.0


2.0


5.7


1.3


12.7




2.1



1.0



3.4


12.6


5.9


6.9


3.0


nt, %
Pa05
.5


.3


.2


.5


.3




.6



.1



.6


.6


.8


.6


1.1



Si02
40.2


43.4


40.5


33.5


32.8




37.0



44.1



38.5


35.3


44.0


29.1


33.9



S03
10.6


9.6


12.2


10.1


12.7




13.6



13.6



13.4


13.0


6.7


14.0

•
16.0



Ti02
.8


.8


1.0


.8


.8




1.1



.8



1.1


.9


1.0


.8


.6



Total
96.7


97.1


97.2


93.5


97.2




98.2



97.8



98.8


100.5


96.0


92.5


96.3












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-------
42
          STRIP?ABLE COAL, SOUTHEASTERN MONTANA
               GEOLOGIC STRUCTURE
                                                     COAL QUALITY
   The strata dip gently to the southeast 40 to 80 feet
per mile. Numerous reversals are associated with faulting
in the southern part of T. 6 S., R. 41 E., and the northern
part of T. 7 S., R. 41 E., where dips are as much as three
degrees next to  the fault  traces. These faults are easily
discernible on aerial photos in the areas  where they are
shown on Plate 6 as solid lines.

                     COAL BEDS

   The principal coal  beds in the Canyon Creek coal de-
posits are the Canyon, Wall, and Brewster-Arnold beds.
The Canyon bed is 200 to 250 feet above the Wall bed
where drilled near Prairie Dog Creek and the north fork
of Canyon Creek. Drill hole SH47, sec. 3, and SH48,
sec. 16, T. 6 S., R. 40 E., penetrated thicknesses of 28 and
29 feet, respectively.  Strippable reserves are not shown
for  the Canyon bed,  however, because it could be strip
mined only in the narrow valley bottom along Prairie
Dog Creek and some  of the  forks of Canyon Creek. The
steep slopes along the sides of the narrow valleys restrict
the  strippable areas because of the excessive overburden.

   The Wall coal bed has been drilled throughout the area.
 Its thickness ranges from  32 feet  in drill hole SH-110,
sec. 33, T. 5 S., R. 41  E., in the northern  part of the area
to 60 feet in drill holes SH-50, sec. 1, T. 7 S., R. 40 E., and
 SH-49, sec. 24,T. 6 S.,  R. 40 E. Even though the Wall coal
 bed is thinnest in the northern part of the area, strippable
 coal is outlined along Cook Creek in T. 5 S., R. 41 and 42 E

   The Brewster-Arnold coal  bed is 18 feet thick and
 forms two benches, which are  separated by a parting 2
 feet thick, as shown in drill hole SH-7057, sec. 28, T. 5 S.,
 R- 42 E. This corresponds well with the  measured thick-
 nesses of the Brewster-Arnold coal bed in the Birney coal
 field (PI. 7).
                                    Core samples were obtained from the Canyon, Wall,
                                 and  Brewster-Arnold coal beds. Analytical  results  on
                                 these core samples are shown in Tables 17 and 18.

                                                    COAL RESERVES

                                    Strippable reserves in the Wall and Brewster-Arnold
                                 coal beds total 1,950,110,000 tons. The Wall bed accounts
                                 for 1,884,250,000 tons and the Brewster-Arnold bed  for
                                 65,860,000 tons (Table  16).

                                               BIRNEY COAL DEPOSIT

                                                      LOCATION

                                    The Birney coal deposit (PI. 7) is in T. 6 and 7 S., R. 41
                                 and  42 E., Rosebud County. The deposit occupies  the
                                 valleys of  Tongue River and its tributaries. Its western
                                 part is overlapped by the Canyon Creek deposit (PI. 6).

                                          FIELD WORK AND MAP PREPARATION

                                    The drilling program  in the Birney area was completed
                                 in 1969. In 1972 the area was mapped on  7^-minute
                                 topographic maps and black-and-white aerial photos.

                                              PREVIOUS GEOLOGIC WORK

                                    This deposit was described in the US. Geological Sur-
                                 vey  report on the northern extension  of  the Sheridan
                                 coal  field  (Baker,  1929). Ayler, Smith, and Deutman
                                 (1969) included it in their report on the strippable coal
                                 in Montana.

                                                   LAND OWNERSHIP

                                    Most of the surface in the Birney coal field  is privately
                                 owned with the exception of sec. 16 and 36 in each town-
                  Table 19.—Reserves, overburden, overburden ratio, acres, and tons/acre, Birney coal deposit.
                                                BREWSTER-ARNOLD BED
        Thickness of
       overburden, ft.
Indicated reserves,
  million tons
 Overburden,
million cu. yd.
   Overburden ratio,
    cubic yards/ton
                                                                                     Acres
                  Tons/acre
           Oto  50
          50 to 100
         100 to 150
                    Total
    50.52
    58.41
    71.62
   180.55
                                         Total
     105.63
     289.63
     525.33
     920.59
        2.09
        435
        7.33
Average  S.09
                                                     Total
1,977.6             25^46.1
2,387.2             24,467.9
2.604.8             27.495.4
6,969.6     Average  25,905.4

-------
                                               Table 20.-Proximtte analysis, fomu of sulfur, and heating value, Birney coal deposit.
                                                                                Proximate.
                                                                                                    Form of sulfur, %
 Drillhole
and location
SH-43
6S 42E S32
ABBD

SH-44
6S42ES31
DBCB
SH-114 */
6S 43E S20
BDAB
SH-116
6S 42E S27
CBCA
 Depth
sampled
 54 to
 64ft.
 70 to
 75ft.

 75 to
 83ft.
 90 to
 94ft.

 94 to
 99ft.
 60 to
 66ft.

 66 to
 74ft.
 Lab.
numbei
  99



 110


 111



 149


 150



 151


 152
 Coal
 bed
            Brewster-
            Arnold
Brewster-
Arnold
Brewster-
Arnold
Brewster-
Arnold
Form of
   A
   B
   C

   A
   B
   C
   A
   B
   C

   A
   B
   C
   A
   B
   C

   A
   B
   C
   A
   B
   C
        1,

Moisture
24.980


24.400


23.600


19.500


21.150


18.290


22.760


Volatile
matter
29.494
39.315
41.876
29.574
39.120
41.615
33.550
43.913
45.788
31.676
39.350
43.853
29.757
37.738
40.240
31.328
38.341
41.757
30.726
39.780
41.935
Fixed
carbon
40.938
54.569
58.124
41.492
54.883
58.385
39.722
51.992
54.212
40.558
50.382
56.147
44.191
56.045
59.760
43.697
53.479
58.243
42.545
55.081
58.065

Ash
4.588
6.115

4.534
5.997

3.128
4.094

8.266
10.268

4.902
6.217

6.684
8.180

3.969
5.138


Sulfur
.241
.321
.342
.347
.459
.488
.708
.927
.967
.367
.456
.509
.236
.299
.319
.292
.358
.390
.725
.938
.989

Sulfate
.034
.046
.049
.025
.033
.035
.034
.044
.046
.018
.023
.025
.027
.034
.037
.028
.035
.038
.071
.092
.097

Pyritic
.112
.149
.159
.033
.044
.046
.067
.088
.092
.110
.137
.153
.072
.092
.098
.075
.092
.101
.141
.183
.193

Organic
.095
.126
.134
.289
.382
.407
.607
.795
.829
.239
.297
.331
.136
.172
.184
.189
.231
.251
.513
.664
.700
Heating
value (Btu)
8786
11711
12474
9191
12158
12933
9389
12289
12814
9417
11698
13036
7987
10130
10801
9346
11438
12457
9274
12007
12658




2
a
[V1DUAL I
n
•«
o
CO
ITS— BIRNE1
•N







1
 /A, as received; B, moisture free; C, moisture and ash free.
 / Not shown on map.

-------
                 Table 21.-Major ash constituent!, Birney coal deposit.
Coal
Constituent, %
and location
SH-43
6S 42E S32
ABBD
SH-44
6S42ES31
DBCB

SH-114
6S 43E S20
BDAB

SH-116
6S 42E S27
CBCA
— - • 	
sampled

54 to
64ft.

70 to
83ft.


90 to
99ft.


60 to
74ft.
sample bed A12O3 CaO Fe2O3 K2O MgO Na2O P2O5 SiOj SO3 TiO2 Total
Brewster- 20.6 11.0 5.5 .6 3.4 7.3 1.0 35.8 11.1 .7 97.0
Arnold
99
Brewster- 16.4 16.4 5.5 .3 10.9 4.5 .6 28.3 18.9 .7 102.5
Arnold
110-111

Brewster- 18.6 11.8 3.3 1.3 3.3 10.9 .4 33.7 7.9 .9 92.1
Arnold
149-150

Brewster- 17.9 13.8 4.0 .3 8.4 2.5 .8 33.2 15.3 1.0 97.2
Arnold
151-152


H
i
1
Ifli
O
f
09
O
1
B
&
8
B
O
25

-------
                                       INDIVIDUAL, DEPOSITS—BIRNEY
                                                                                                         45
ship, which are owned by the State of Montana. The Fed-
eral Government owns some of the surface a short dis-
tance west of the main valley of the Tongue River. Some
coal in the valley bottom along Tongue River and its trib-
utaries is privately  owned, and the State of Montana has
the coal rights on its land, but the Federal Government
owns the rest, which is the largest share of the coal.

          SURFACE FEATURES AND LAND USE

   The Tongue  River flows through the area in a north-
easterly direction and has cut a deep valley bordered by
clinker-topped ridges and knobs. Steep and rugged valley
sides border a narrow flood plain. The northwest-trending
tributaries east  of the Tongue River are relatively short
and steep; the southeast-trending tributaries west of the
river are longer. Ponderosa pine trees grow on the steep
sides of the tributary valleys and on large clinkered areas.

   The principal land use in the area is livestock grazing.
Hay  is raised in meadows along  the flood plain of the
Tongue River.

               GEOLOGIC STRUCTURE

   The strata dip gently to the southeast. In drill hole
SH-33, sec. 12, T.  6 S., R. 41 E., the Brewster-Arnold
coal bed is 105  feet higher than in drill hole SH43, sec.
32, T. 6 S., R. 42 E.

                    COAL BEDS

   The Brewster-Arnold coal bed contains strippable re-
serves in the Birney area. Where the bed is exposed above
river level, it has burned along its outcrop in the northern
part of the area. The Wall coal bed, which is about 275
feet higher, has burned along the Tongue River and its
clinker caps the buttes and ridges. The Brewster-Arnold
coal bed is 20 feet thick in drill hole SH-43, sec. 32, T. 6 S.,
R. 42 E. The bed thins westward and develops a parting,
which thickens westward. A gamma log in SE& sec. 24,
T. 6 S., R.  41 E., shows that the Brewster-Arnold coal
bed there forms two benches; the upper 10 feet thick and
the lower 6 feet thick, separated by a  2-foot parting.
This parting thickens westward and is 10 feet thick in the
NWVi sec. 21, T. 6 S., R. 41  E., as shown by a gamma log
of an oil well. On this log, the  upper bench  is  11 feet
thick and the lower, 6 feet.

                   COAL QUALITY

   An earlier U.S. Bureau of Mines analysis of a sample
from the abandoned Brewster-Arnold mine, sec. 23, T. 6 S.,
R. 42 E., agrees closely with our later analysis, which re-
ports moisture on the "as received" basis as 27.3%, vola-
tile matter 285%, fixed carbon 39.2%, ash 4.6%, sulfur
0.6%, and heating value 8,850 Btu.

   Seven core samples obtained from the Brewster-Arnold
coal bed during the current project were analyzed by the
Montana  Bureau of Mines and Geology analytical labora-
tory. Proximate analysis, sulfur forms, and calorific value
are shown in Table 20, and major ash constituents are
shown in Table 21.

                  COAL RESERVES

   Strippable coal reserves in the Brewster-Arnold coal
bed total  180,550,000 tons (Table 19).

-------
46
                   STRIPPABLE COAL. SOUTHEASTERN MONTANA

Table 22.-Reserves, overburden, overburden ratio, acres, and tons/acre, Poker Jim Lookout coal deposit.
                                           ANDERSON and DIETZ BEDS
    Thickness of
   overburden, ft.
      Indicated reserves,
        million tons
Overburden and
 interbuiden,
million cu. yd.
Overburden ratio,
 cubic yards/ton
         Acres
                   Tons/acre
       Oto  50
      50 to 100
     100 to 150
     150 to 200
                Total
                               237.71
                              1,485.94
                               528.91
                               377.29
                       Total   2,629.85
                Average
      1.35
      3.21
      3.65
      4.20
      3.01
Total
 4,166.4
11,744.0
 2,419.2
 1.280.0
19,609.6
Average
42,177.9
39,357.1
59,908.2
70.140.6
44,501.2
       POKER JIM LOOKOUT COAL DEPOSIT

                     LOCATION

   The Poker Jim Lookout coal deposit (PI. 8) in T. 6 and
 7 S., R. 44 and 45 E., in  Powder River and Rosebud
 Counties, is on a high divide between Otter Creek to the
 east and Hanging Woman Creek to the west. The area is
 within the boundary of the Custer National  Forest and
 adjoins the  Hanging Woman Creek coal deposit (PL 9A
 and B) to the south.

          FIELD WORK AND MAP PREPARATION

   Field work in the Poker Jim Lookout area, begun in
 1969, included the drilling of four holes. One hole, drilled
 in 1970,  penetrated lower  coal beds in sec. 9, T. 7 S.,
 R. 44 E. The geology was mapped with the help of color
 aerial photos borrowed from the Custer National Forest
 Service; overburden  maps were prepared on 7&-minute
 topographic maps.

              PREVIOUS GEOLOGIC WORK

   The northern part of the Poker Jim Lookout coal de-
 posit was included in the U. S. Geological  Survey report
 on  the Birney-Broadus  coal field (Warren, 1959).  The
 southern  part was included in a US. Geological Survey
 open-file  report on  the Moorhead coal field (Bryson and
 Bass, 1966).

                  I AND OWNERSHIP

   The Poker Jim Lookout coal deposit lies within the
 Custer National Forest.

          SURFACE FEATURES AND LAND USE

   The Poker Jim Lookout deposit  is on  the divide be-
 tween Otter Cre«k and the East Fork of Hanging Woman
 Creek, an intermittent  tributary  of the Tongue  River.
                                           The top of the divide is smooth, rolling, and covered with
                                           native grasses, but the edges are steep and rugged where
                                           thick clinker occurs. The clinkered areas and the valley
                                           sides support lush growths of ponderosa pine and other
                                           trees.

                                              The principal land use is livestock grazing. Many near-
                                           by ranchers have grazing permits on Forest Service land.

                                                          GEOLOGIC STRUCTURE

                                              The strata in the Poker Jim Lookout coal deposit dip
                                           to the south at 40 feet per mile.

                                                                COAL BEDS

                                              Beds of economic importance in the Poker Jim Look-
                                           out deposit are the Anderson and Dietz coal beds, which
                                           converge in T. 6 S., R. 44 E., to form a coal bed 58 feet
                                           thick, as shown in drill hole SH-8, in sec. 9, T. 6 S., R. 44 E.
                                           In drill hole SH-7, in sec. 24, the two beds are separated
                                           by a parting of 17 feet and have a combined thickness of
                                           59 feet. The parting thickens southward, and in sec. 36 it
                                           is 40 feet thick according to a gamma log. In  SH-7, the
                                           Dietz coal bed is 25 feet thick, but it thins southward to
                                           14 feet, as shown  in the gamma  log. Thickness of the
                                           Anderson bed is almost uniform,  being 34 feet in SH-7
                                           and 31 feet in SH-5 and SH-6.

                                                              COAL QUALITY

                                              Eleven core samples obtained during the field evalua-
                                           tion  were analyzed by the Montana Bureau of Mines and
                                           Geology analytical laboratory. Proximate analysis, sulfur
                                          • forms, and heating  value are shown in Table 23. Major
                                           ash constituents are shown in Table 24.

                                                             COAL RESERVES

                                              Reserves  in the Anderson and Dietz  coal beds total
                                           872,650,000 tons (Table 22).

-------
                                          Table 23.-Proximtte analysis, forms of sulfur, and heating value, Poker Jim Lookout coal deposit.
 Drillhole
and location
SH-S
7SR44ES13
ADBA
SH-6
7SR44ES11
ABBB

SH-7
6S R44E S24
BDCB

SH-8
6S R44E S9
ACCC
SH-7038
78 R44F-. S9
DCBC
 Depth
sampled
 94 to
104ft.

104to
109ft.
163 to
172 ft
186 to
196 ft.
105 to
115ft.

I IS to
123ft

123 to
131 ft.

131 to
141 ft.
 33 to
 43ft.

 43 to
 S3 ft

 S3 to
 63ft.
  Lab.
number
  16


  17



  18



  59



  60


  61


  62


  63



 213


 214


 215
Coal
bed
                       Anderson
                       Anderson
                       Anderson
                       Anderson
                       Canyon
Form of,
             A
             B
             C
             A
             B
             C

             A
             B
             C

             A
             B
             C

             A
             B
             C
             A
             B
             C
             A
             B
             C
             A
             B
             C

             A
             B
             C
             A
             B
             C
             A
             B
             C
                                                                               Proximate. %
                                                                                                  Form of sulfur. %

Moisture
27.540


27.390


27.000


30.580


31.870


31.400


31.970


29.260


30.000


30.560


30.890


Volatile
matter
31.587
43.592
46.209
31.455
43.321
45.919
32.853
45.003
51.253
28.830
41.529
44.240
27.590
40.496
45.711
29.176
42.531
45.277
28.539
41.951
44.541
30.074
42.513
45.717
30.522
43.602
48.704
30.251
43.565
46.059
27.624
39.971
42.369
Fixed
carbon
36.770
50.745
53.791
37.046
51.020
54.081
31.246
42.802
48.747
36.337
52.343
55.760
32.767
48.095
54.289
35.264
51.405
54.723
35.534
52.233
55.459
35.708
50.478
54.283
32.146
45.923
51.296
35.428
51.020
53.941
37.575
54.369
57.631

Ash
4.103
5.663

4.109
5.659

8.902
12.194

4.253
6.127

7.773
11.409

4.160
6.065

3.957
5.816

4.958
7.009

7.332
10.475

3.761
S.416

3.912
5.660


Sulfur
.184
.254
.270
.278
.383
.406
.876
1.200
1.366
.087
.126
.134
.761
1.117
1.261
.298
.435
.463
.230
.337
.358
.286
.405
.436
.660
.943
1.054
.165
.237
.251
.289
.419
.444

Sulfate
.050
.069
.074
.000
.000
.000
.085
.116
.133
.008
.011
.012
.023
.034
.038
.023
.033
.036
.023
.034
.036
.024
.034
.036
.015
.022
.024
.022
.032
.034
.016
.023
.024

Pyritic
.000
.000
.000
.017
.023
.025
.332
.454
.517
.016
.023
.024
.206
.302
.341
.054
.078
.083
.069
.101
.108
.056
.079
.085
.250
.358
.400
.082
.119
.125
.070
.102
.108

Organic
.134
.185
.196
.261
.359
.381
.459
.629
.716
.063
.091
.097
.533
.782
.883
.222
.323
.344
.138
.202
.215
.207
.292
.315
.395
.564
.630
.060
.086
.091
.203
.294
.312
Heating
value (Btu)
8203
11321
12000
8374
11533
12225
7826
10721
12210

7770
11193
11924

7637
11209
12653
8007
11672
12426
7715
11340
12040
7874
11131
11970
7862
11231
12545
8801
12675
13400
7939
11487
12177








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-------
Table 24.-Major uh coiulhuenta, Fokat Jfan Lookout coal dcpodt.
                                            Coiutituent. %
utd location
8H-3
7844ES13
ADDA


SH-6
7S44ES11
ABBB


SH-7
6S 44E S24
BDCB


SH-8
6S44ES9
ACCC

SH-7038
7S44ES9
DCBC
utnpled number bed AljOj CaO FejOj K5O MgO NajO PjOs SK>a SO3 TiOj Total
Andenon 13.1 26.2 4.5 .3 6.7 11.9 JS 24.1 10.8 IX) 99.1
94 to
109 n. 16-17


Andenon 14.2 9.6 9.0 1.3 3 A 6.7 A 35.3 16.4 A 96.9
163 to
172 ft. 18


Andenon 12.8 18.7 5.4 .8 4.4 124) .2 28.3 8.4 .7 91.7
186 to
196 ft. 59


Andenon 15.6 19.5 4.2 .6 6.9 3.6 A 284) 17.2 ID 97.4
105 to
141 ft. 6043

Canyon 13.9 18.5 5.8 .7 10.0 2.6 .3 31.7 14.6 .7 98.8
33 to
63 n. 213-215

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-------
                              INDIVIDUAL DEPOSITS—HANGING WOMAN CREEK
                                                                                                      49
          Trite 25.-RMMVM, overburden, overburden ntio, KIM, and toni/acre, Hanging Woman Geek MM! deporit.
                                       ANDERSON and DffiTZ BEDS
 Thickneu of
overburden, ft.
    Indlcited reiervei,
      million tons
    Overburden,
   million co. yd.
  Overburden ratio,
  cubic yaxdt/ton*
        Acre*
                 Tons/acre
    Oto 50
   50 to 100
  100 to 150
        599.87
      1/420.92
        683.46
Total  2,704.25
        370.81
      5,260.47
      2.672,48
Total  8303.76
        0.61
        3.70
        351
Avenge  3.07
                                                                   Total
        17,593.6           34,0955
        43/404.8           32,736.5
        13.203.2           51.764.7
        74,201.6   Avenge  36/444.6
                                            ANDERSON BED
    Oto 50
   50 to 100
  100 to 150
            Total
        29655
        602.88
        683/46
      1,583.29
        313.82
       U95.47
       2.672/48
Total   4^81.77
        1.05
        2.31
        3.91
Avenge  2.76
Total
 5,849.6
11,494.4
13.203.2
30,547.2
                                                            50,764.2
                                                            52/51.7
                                                            51.765-5
                                                    Avenge  513305
                                               D1ETZBED
    Oto 50
   50 to 100
            Total
        30252
        818.04
      1,12056
         5659
      3.865.00
Total  352159
                          0.18
                          4.72
                          3>49
                Total
        11,7444
        31510.4
        43,654.4
                  25,793.6
                  25.6355
                  25,678.1
     HANGING WOMAN CREEK COAL DEPOSIT

                    LOCATION

   The Hanging Woman Creek coal deposit (PL 9), in T. 7,
8, and 9 S., R. 42, 43, 44, and 45 £., is bounded on the
west by the  high ridge between Hanging Woman Creek
and the Tongue River valley, where increasing thickness
of overburden makes strip mining impractical. On  the
south also it is bounded by excessive overburden. On the
east, it abuts the West Moorhead coal deposit (PL 10A.B,
and C). On the north, nigged topography and the outcrop
of the coal beds limit the deposit. In T.7 S..R.44 £., the
deposit joins the Poker Jim Lookout coal deposit (PL 8),
which has reserves in the same coal beds.
                                          cellent information, became gamma logs were run to the
                                          surface. DriD logs of water weDs in part of the area were
                                          obtained from the Kendrick Land and Cattk Company.

                                                       PREVIOUS GEOLOGIC WORK

                                             Portions  of  the Ha«gp»g Woman  Creek area  were
                                          mapped and described in a US. Geological Survey
                                          (Baker, 1929) and in an open-file report on the Moorhead
                                          coal field (Bryson and Bass, 1966). Aykr, Smith, and
                                          Deutman (1969) in describing the strippaUe cod in Mon-
                                          tana, included a deposit in the Dietz No. 1 cornl bed along
                                          the valley of Hanging Woman Creek.

                                                           LAND OWNERSHIP
         FIELD WORK AND MAP PREPARATION

   Drilling in the Hanging Woman Creek area, begun in
1969, was completed in 1970. Outcrops of coal beds and
limits of clinker were mapped in 1969; this work was sup-
plemented by geologic interpretation of color photos bor-
rowed from the US. Forest Service and of infrared color
transparencies borrowed from the US. Bureau of Land
Management, Billings. Oil well logs in the area gave ex-
                                             The State of Montana owns a large part of T. 8 &,
                                          R. 43 E^ but in the other townships the state owns only
                                          sec. 16 and 36. The Federal Government owns scat toed
                                          surface tracts throughout the area and the rest of the
                                          surface is privately owned.

                                             Although the Federal Government conveyed the sur-
                                          face to private individuals* it retained ownership of the
                                          coal ID most of the are*. The State of Montana owns the

-------
                                          Table 26.-Proximate analysis, forms of sulfur, and heating value, Hanging Woman Creek coal deposit.
                                                                                                                                                                   01
                                                                                                                                                                   O
  Drill hole
 and location
 SH I
 8S R45E S7
 CAAP
SH-2
8SR44FSI2
SH-3
8S R44I
1XVA
SH-4
7SR44ES26
DBA A
SH-10
7S R44E S31
ACCD
IH-pth
sampled
100 to
108 It.
108 to
1180
83 to
93 n
93 to
103 n
103 to
111 ft
111 to
112 ft.
88 to
98 n
98 to
108 ft.
108 to
116ft.
94 to
104 ft.
104 to
112 ft
112 to
120ft.
113 to
123 ft.
123 to
131ft.
130 to
140ft.
140 to
149ft.
Lab.
number
2
3
6
7
8
9
10
11
12
13
14
15
19
20
21
22
  Coal
  bed
 Anderson
Anderson
Anderson
Anderson
                                           Anderson
Anderson
Proximate. %
l-'orm of
analysis
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
C
I
'/ Moisture
20.600


24.400


27.260


28.180


26.830


27.000


27.400


28.400


27.150


29.220


27.470


26.360


27.700


22.850


25.550


27.440
Volatile
matter
32.943
41.490
44.233
31.899
42.195
44.668
31.072
42.716
44.979
31.238
43.494
46.109
30.897
42.226
45.063
29.920
40.986
42.880
29.752
40.980
43.564
30.283
42.294
46.438
29.364
40.307
44.147
21.887
30.923
32.759
30.085
41.479
43.700
35.710
48.493
50.808
32.308
44.686
46.874
30.042
38.939
51.154
31.537
42.361
45.255
30.586
44/788
Fixed
carbon
41.534
52.309
55.767
39.514
52.267
55.332
38.008
52.252
55.021
36.510
50.835
53.891
37.667
51.479
54.937
39.855
54.596
57.120
38.542
53.088
56.436
34.929
48.783
53.562
37.150
50.995
55.853
44.925
63.472
67.241
38.760
53.440
56.300
34.574
46.950
49.192
36.617
50.646
53.126
28.686
37.182
48.846
38.151
51.244
54.745
37.705
51.963
55.212

Ash
4.923
6.201

4.187
5.538

3.660
5.032

4.073
5.671

4.606
6.294

3.225
4.418

4.306
5.931

6.388
8.922

6.337
8.698

3.968
5.606

3.685
5.081

3.356
4.557

3.375
4.668

18.422
23.878

4.761
6.396

4.270
5.884

Sulfur
.282
.355
.379
.262
.346
.366
.204
.281
.296
.330
.459
.487
.350
.478
.510
.780
1.068
1.118
.204
.281
.298
.224
.313
.344
.199
.273
.299
.147
.208
.220
.154
.212
.223
.128
.174
.182
.197
.272
.285
2.132
2.764
3.631
.330
.443
.473
.311
.429
.455
Form o

Sulfate
.027
.034
.037
.026
.035
.037
.025
.034
.035
.040
.056
.059
.041
.056
.059
.114
.156
.163
.042
.058
.062
.025
.035
.038
.033
.045
.050
.016
.023
.024
.009
.012
.012
.009
.012
.012
.033
.045
.048
.846
1.097
1.441
.059
.080
.085
.042
.058
.062
fuilfnr %

Pyritic
.064
.080
.086
.044
.058
.061
.025
.034
.035
.064
.090
.095
.057
.078
.083
.138
.189
.198
.042
.058
.062
.025
.035
.038
.041
.057
.062
.000
.000
.000
.000
.000
.000
.000
.000
.000
.033
.045
.048
.613
.794
1.044
.068
.091
.097
.092
.127
.135


Organic
.191
.241
.257
.192
.254
.269
.155
.213
.225
.225
.314
.333
.252
.345
.368
.528
.723
.757
.119
.164
.174
.174
.243
.267
.124
.171
.187
.131
.185
.196
.145
.200
.211
.120
.162
.170
.131
.181
.190
.673
.873
1.147
.203
.273
.291
.177
.243
.258

Heating
value (Btu)
9259
11661
12432
8718
11531
12207
8440
11603
12218
8151
11349
12032
8281
11318
12078
7865
10775
11273
8544
11769
12511
8706
12160
13351
8184
11234
12304
8056
11382
12058
8174
11270
11873
8583
11656
12212
8403
11622
12192
6751
8750
11495
8780
11794
12600
8418
11601
12326












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-------
SH-10
7S R44E S31
ACCD
SH-11
8S R43E S10
CACC

SH-13
8S R44E S19
DBAC
SH-14
8S R44I S30
BCCB

SH-1S
9S R43E S2
BBAA
SH 16
»S R441 S7
BACC
SH-J7
9S R44E S8
CBBA
SH-18
9S R44E 522
a: AD
149 to
157 ft.

157 to
158ft.
134 to
144ft.
 88 to
 96ft.

 96 to
102 ft
160 to
167 ft.
104 to
113ft.

113 to
123 ft

123 to
128ft.
 63 to
 70ft.

 70 to
 79ft.
I 80 to
188 ft

188 to
197ft.

197 to
200/1
 63 lo
 72 fl
23


24



25



26


27



28



29


30


31



32


33



35


36


37



38
Anderson






Anderson



Anderson






Anderson



Anderion
                      Anderson
                                          Anderson
                      Anderson
A
B
C
A
B
C

A
B
C

A
B
C
A
B
C

A
B
C

A
B
C
A
B
C
A
B
C

A
B
C
A
B
C

A
B
C
A
l<
C
A
11
r

A
B
C
28.300


20.320


28.960


25.550

28.530


27.540


27.300


26.380

23.360


26.530

24.980


25.690

25.630


24.330


28.540


30.878
43.065
46.159
30.878
43.065
46.159
30.440
42.849
44.871
32.810
44.070
45.979
29.500
41.276
43.326
25.919
35.771
37.599
30.446
41.880
43.999
29.739
40.395
42.536
30.283
39.514
44.082
29.719
40.451
42.644
31.900
42.522
48.420
33.144
44.603
47.456
30.252
40.678
42.763
29.1 12
39.265
47.522
30.561
42.766
45.743
36.017
50.233
53.841
36.017
50.233
53.841
37.398
52.644
55.129
38.548
51.777
54.021
38.588
53.992
56.674
43.016
59.366
62.401
38.752
53.303
56.001
40.175
54.571
57.464
38.415
50.124
55.918
39.972
54.406
57.356
33.982
45.297
51.580
ftffi
52.544
40.491
54.445
57.237
32.771
43.308
52.448
36.249
50.727
54.257
4.806
6.702

4.806
6.702

3.202
4.507

3.092
4.153

3.382
4.732

3.524
4.863

3.502
4.817

3.706
5.034
7.942
10.362

3.778
5.143
9.139
12.182

4.469
6.013

3.627
4.876

13.187
17.428

4.650
6.507

.310
.432
.463
.310
.432
.463
.196
.275
.288
.211
.283
.295
.097
.136
.142
.065
.090
.095
.106
.146
.154
.174
.237
.250
.371
.484
.540
.225
m
.549
.732
.834
.202
.271
.289
.093
.125
.131
1.Q34
1.366
1.655
.219
.307
.328
.057
.080
.085
.057
.080
.085
.024
.034
.036
.008
.011
.012
.000
.000
.000
.000
.000
.000
.008
.011
.012
.025
.034
.036
.060
.079
.088
.042
!060
.057
.076
.087
.008
.011
.012
.008
.011
.012
.118
.156
.188
.041
.057
.061
.073
.102
.110
.073
.102
.110
.024
.034
.036
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.017
.023
.024
.069
.090
.100
.058
.079
090
!l20
.137
.034
.045
.048
.000
.000
.000
.706
.933
1.115
.065
.091
.097
8266
11529
12357
8266
11529
12357
8379
11795
12352
8896
11949
12467
8506
11902
12493

8595
11862
12468

8615
11850
12450
8788
11937
12570
8597
11217
12514
8726
11877
12521
8290
11050
12583

8835
11890
12651
8777
11802
12407
7863
10391
12584
8258
11556
12360









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 /A, »i received; B, inoislure lice, >"., moisture and .nli free

-------
                                                                 Table 26 (Continued).
                                                                                                                                                        to
 Drill hole
and location
SH 18
9S R44B SU
OCAD
SH-19
9SR44ES19
                                                                            aximate. %
Form of sulfur. %
SH-20
9SR4.U S24
AACA
SH-21
9S R431 Sll
DCAC
SH-22
9S R43E S4
DBDD

SH-23
9S R43E S22
DBDD

SH-24
9SR43ES3S
BCAC

SH-26
9S R43E S6
OCDB
Depth
sampled

72 to
80ft

80 to
83ft.

151 to
156ft.

74 to
84ft.

84 to
92ft.

92 to
100ft.

110 to
119ft.

119 to
124ft.

124 to
129ft.


63 to
73ft.

73 to
80ft.

80 to
85ft.

93 to
98ft.

130 to
140 ft.

95 to
101ft.

114 to
124 ft.
Lab.
number


39


40


41


42


43


44


45


46


47



48


49


50


51


54


55


64
Coal
bed
Anderson





Dietz


Anderson








Anderson









Anderson








Anderson


Anderson


Smith


Anderson


Form of i
analysis '/
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
Moisture
27.630


27.220


25.830


24.160


23.830


26.640


25.850


21.460


25.280



26.130


26.100


27.510


26.190


24.540


23.710


26.490


Volatile
matter
33.369
46.108
48.839
29.929
41.122
43.457
29.854
40.251
46.514
30.905
40.750
44.115
31.525
41.388
43.830
29.497
40.208
42.185
29.469
39.742
41.438
32.017
40.766
51.188
29.812
39.899
41.716

29.702
40.209
42.143
28.753
38.909
42.621
28.176
38.869
41.685
29.039
39.343
41.973
29.824
39.523
41.830
28.182
36.941
43.900
28.547
38.834
40.779
Fixed
carbon
34.956
48.301
51.161
38.941
53.504
56.543
34.329
46.284
53.486
39.151
51.623
55.885
40.401
53.040
56.170
40.425
55.105
57.815
41.647
56.166
58.562
30.531
38.874
48.812
41.653
55.746
58.284

40.778
55.202
57.857
38.709
52.380
57.379
39.417
54.375
58.315
40.146
54.391
58.027
41.474
54.962
58.170
36.014
47.207
56.100
41.456
56.395
59.221
Ash
4.046
5.590

3.911
5.373

9.987
13.465

5.784
7.627

4.244
5.572

3.438
4.686

3.034
4.092

15.991
20.361

3.255
4.356


3.390
4.589

6.437
8.711

4.897
6.756

4.625
6.266

4.162
5.515

12.094
15.853

3.507
4.771

Sulfur
.247
.341
.261
.231
.318
.336
.477
.643
.743
.170
.225
.243
.284
.373
.395
.191
.260
.273
.141
.191
.199
.242
.308
.387
.143
.191
.200

.109
.148
.155
.430
.582
.638
.123
.170
.182
.075
.102
.109
.196
.260
.275
.787
1.031
1.225
.166
.226
.237
Sulfate
.041
.057
.060
.050
.068
.072
.000
.000
.000
.034 •
.045
.049
.026
.034
.036
.025
.034
.036
.000
.000
.000
.000
.000
.000
.000
.000
.000

.034
.045
.048
.160
.217
.238
.025
.034
.036
.000
.000
.000
.017
.023
.024
.052
.068
.081
.000
.000
.000
Pyritic
.025
.034
.036
.033
.045
.048
.033
.044
.051
.034
.045
.049
.095
.124
.132
.066
.091
.095
.000
.000
.000
.026
.033
.041
.000
.000
.000

.017
.023
.024
.110
.148
.163
.008
.011
.012
.000
.000
.000
.017
.023
.024
.199
.261
.310
.041
.056
.059
Organic
.181
.250
.265
.149
.204
.216
.444
.599
.692
.102
.135
.146
.164
.215
.227
.100
.136
.143
.141
.191
.199
.216
.275
.345
.143
.191
.200

.059
.080
.083
.160
.217
.238
.090
.125
.134
.075
.102
.109
.162
.215
.227
.536
.703
.835
.124
.169
.178
Heating
value (Bui)
8245
11393
12068
8438
11594
12252
7722
10411
12032
8390
11063
11976
8802
11555
12237
8306
11322
11879
8893
11993
12505
7573'
9643
12108
8840
11831
12370

8901
12050
12630
8135
11008
12059
8445
11650
12495
8521
11544
12316
8685
11510
12182
7877
10325
12270
8744
11895
12491












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SH-26
9S 43E S6
CCDB
SH-27
8S43ES31
CABB
SH-28
85 42E S24
DBAA

SH-29
8S42ES12
CBDD
SH-57
7S 44E S28
BACC
SH-118
8S 44E S2
DBCA
SH-119
9S43ES15
CBCA
SH-7039
7S44ESJ9
CCAU
SI I -7040
7S 44E S27
BBAA
124 to
132 ft.

132 to
135ft.
137 to
145 ft.

145 to
155 ft.

155 to
162 ft.
 93 to
102ft.


 89 to
 97ft.

 97 to
106ft.

106 to
115ft.
110 to
118ft.

118 to
126ft.
 53 to
 62ft.

 62 to
 65ft.
110 to
119ft.

119 to
127ft.


 46 to
 60ft.

 60 to
 70ft.


 63 to
 67ft.
 65


 66



 67


 68


 69



 70



 71


 72


 73



 56


 57



  4


  5



 52


 53



217


218



219
                      Anderson
                      Anderson
Anderson



Anderson
                      Canyon
                      Dtetz
                      Anderson
Canyon
                                          Dietz
A
B
C
A
B
C

A
B
C
A
B
C
A
B
C

A
B
C

A
B
C
A
B
C
A
B
C

A
B
C
A
B
C

A
B
C
A
B
C

A
B
C
A
B
C

A
B
C
A
B
C

A
B
C
25.580


26.670


25420

24.140


25.010


25.940

26.460


24.810


25.180

23.740


24.620


23.890


28.170


27.130


24.230

23.080


29.180

31.800

31.117
41.812
44.011
29.842
40.696
43.041
29.643
39.800
42.446
30.280
39.915
44.947
28.030
37.379
39.077
31.622
42.697
44.693
29.503

42*446
30*220
40.192
42.134
30.544
40.824
42.721
31.258
40.989
46.101
30.778
40.830
42.909
31.205

431325
31.519
43.880
46.250
29.418
40.370
42.147
29.688
39.182
41.387
30.858
40.116
42.289
26.866
37.936
43.736
$18
44*522
39485
53.191
55.989
39.492
53.855
56.959
40.194
53.966
57454
37.089
48.891
55.053
43.701
58.275
60.923
39.131
52.837
55.307
40.004
54.398
57.554
41.504
55.198
57.866
40.953
54.735
57.279
36.546
47.923
53.899
40.950
54.325
57.091
40.822
53.635
56.675
36.630
50.996
53.750
40.379
55.413
57.853
42.045
55.490
58.613
42.111
54.746
57.711
34.562
48.802
56.264
5?$!
55*478
3.718
4.997

3.996
5.449

4.643
6.234
8.492
11.194

3.259
4.346

3.308
4.466
4.033
5.484

3.466
4.609

3.323
4.441
8.456
11.088

3.652
4.845

4.083
5.365

3.681
5.124

3.073
4.217

4.036
5.327

3.952
5.138

131262

H?!

.313
.420
.442
.230
.313
.331
.134
.180
.192
.191
.252
.283
.180
.240
.250
.130
.176
.184
.134
.182
.193
.189
.252
.264
.327
til
.612
.802
.902
.219
.291
.306
.268
.352
.372
.297
.414
.436
.148
.203
.212
.307
.405
.428
.258
336
1354
.540
.762
.879
•m
.476
.025
.034
.036
.000
.000
.000
.000
looo
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000


.067
.088
.099
.034
.045
.047
.026
.034
.036
.016
.022
.024
.000
.000
.000
.026
.034
.036
.017
§22
24
23
.033
.038
*8?I
.012
.228
.307
.323
.181
.246
.260

.109
.146
.156
.147
.194
.219
.154
.205
.215

.114
.154
.161

.117
.159
.169
.163
.217
.228
.267
.357
.373

.377
.495
.556
.118
.157
.165

.207
.272
.288
.257
.358
.377

.148
.203
.212
.222
.293
.309

.164
.213
.224
.316
.446
8700
11690
12305
8733
11909
12595
8665
11634
12407
8847
11662
13132
9000
12002
12547
8235
11119
11639

8583
11671
12349
8804
11709
12275
8676
11596
12135
8108
10632
11958
11762
12361
8707
11440
12089
7972
11099
11698
8657
11880
12403
9012
11894
12564
9081
11805
12445
7657
10812
12465














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                                                                                                .209
            12376
    , as received; B, muiiture free; C, moisture md ash free.
                                                                                                                                           u>

-------
Table 27.-Mijoi ash constituents, Hanging Woman Creek coal deposit.
i TUI nun*
and location
SH-1
8S 451: S7
CAAD
SM-2
8S44FS12
nccc
SH-3
8S 44E S3
DCCA

SIM
7S 441-: S26
DBAA
SH-9
7S44ES33
BDCA
SH-10
7S44F S31
ACCI)
SH-11
8S 43E S10
CACC
SH-13
8S 44ES19
DBAC
SH-14
8S 44E S30
BCCB
SH-15
9S 43E S2
BBAA
SH-16
SS 44E S7
BACC
SH-17
9S 44E S8
CBBA
SH-18
9S 44E S22
CCAD
SH-19
9S 44E S19
DDDC
UV\>lll
sampled

100 to
118ft.

83 to
1 12 ft.

88 to
116ft.


94 to
120ft.

113 to
131 ft.

130 to
158 ft.

134 to
144 ft.

88 to
102ft.

160 to
167 ft.

104 to
128 ft.

63 to
83ft.

180 to
200ft.

63 to
83ft.

74 to
100 ft.
l-av.
sample


2-3


6-9


10-12



13-15


19-20


21-24


25


26-27


28


29-31


32-34


35-37


38^0


42-44
v*utu
bed
Anderson


Anderson


Anderson



Anderson


Anderson


Anderson


Anderson


Anderson


Anderson


Anderson


Anderson


Anderson


Anderson


Anderson


A1203
14.8


14.9


14.7



14.6


13.3


14.1





18.5


17.9


18.3


17.9


19.6


14.4


14.6


CaO
26.9


27.8


21.9



27.4


13.3


20.1


22.5


23.6


19.8


12.0


7.6


17.5


21.6


21.2


Fea03
4.7


5.8


4.7



5.5


12.1


5.5





5.7


5.8


5.4


10.4


8.3


6.6


5.0


KaO
.3


.3


.8



.8


.7


.3


.4


.3


.7


1.1


1.1


.3


.2


.2


MgO
7.7


9.2


6.5



7.2


4.8


6.0


6.4


6.4


5.6


3.5


2.6


4.2


8.4


7.4


NaaO
13.8


7.3


16.0



15.8


3.5


13.9


12.2


12.5


9.7


6.6


5.0


7.3


4.0


6.7


P205
.5


.9


.7



.5


.7


.6





.4


.3


.9


.4


.9


1.2


1.1


SiOa
20.0


17.4


31.9



19.7


21.9


24.3





17.6


27.5


41.8


41.7


22.0


23.6


25.6


SO3
12.0


16.4


10.3



10.1


24.1


15.3


13.9


10.1


9.0


9.7


12.0


22.2


15.8


15.2


TiOj
1.0


.7


1.1



.9


.7


1.3





1.2


1.9


1.4


1.0


.9


1.5


1.6


Total
101.7


100.7


108.6



102.5


95.1


101.4





96.3


98.2


100.7


99.7


103.2


97.3


98.6












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-------
SH-20
9S 43E S24
AACA
SH-21
9S43ES11
DCAC
SH-22
9S 43E S4
DBDD
SH-23
9S 43E S22
DBDD
SH-24
9S 43E S35
BCAC
SH-26
9S 43E S6
CCDB
SH-27
8S43ES31
CABB
SH-28
8S 42E S24
DBAA
SH-29
8S42ES12
CBDD
SH-57
7S 44E S28
BACC
SH-118
8S 44E S2
DBCA
SH-119
9S43ES15
CBCA
SH-7039
7S44ES19
CCAB
110 to
129 ft.
63 to
85ft.
93 to
98ft.
130 to
140 ft.
95 to
101 ft.
114 to
135 ft.
137 to
162 ft.
93 to
102 ft.
89 to
115ft.
110 to
126ft.
53 to
65ft.
110 to
127 ft.
46 to
70ft.
45-47
48-50
51
54
55
64-66
67-69
70
71-73
56-57
4-5
52-53
217-218
Anderson
Anderson
Anderson
Anderson
Smith
Anderson
Anderson
Anderson
Anderson
Canyon
Dietz
Anderson
Canyon
14.6
15.4
11.1
15.6
12.8
15.6
14.3
16.4
14.7
15.1
12.8
16.9
13.9
20.3
19.2
17.5
23.4
7.1
19.8
19.6
21.9
19.7
16.9
23.2
20.2
15.6
9.0
8.8
15.9
5.1
12.1
5.0
4.9
5.7
4.6
3.6
5.1
7.9
4.8
.3
.4
.2
.3
1.6
.3
.2
.4
.4
.5
.3
.2
1.8
4.9       10.3      1.0       19.3      14.2    1.2
5.3       10.3       1.1       21.1      12.9    1.5
5.7        7.1        .3       19.4       7.7     .5
6.7        8.3        .3       21.2      10.3   2.4
7.2
2.6       .8       37.1       9.1    .4
6.2        5.9
5.0       11.3
4.9        9.5
          .7
                   23.4      13.9   1.3
4.5       10.8       .6       25.1       9.8    1.3
4.5       14.1        .9       27.7      14.8     .7
6.1       12.9      1.0       20.4      14.0    .8
18.0      15.0    .7
7.7        1.6       .1       42.1       11.6     .6
                                              95.1
                                              96.0
                                              85.4
                                              93.6
                           90.8
                           92.1
                                              91.1
5.4       11.4       .6       24.1      13.7    1.1       100.7
                   20.4      12.9   1.0       90.5
                                              98.8
                                              96.6
94.0
                                              99.8
                    2

                    2


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56
STRIPPABLE COAL, SOUTHEASTERN MONTANA
coal on its school-grant lands; a small amount of coal in
the area is privately owned.

          SURFACE FEATURES AND LAND USE

   The most prominent surface features in the  Hanging
Woman Creek coal deposit are the creek and its  tributar-
ies. Hanging Woman Creek  is an intermittent stream,
which contains water in pools throughout the year, but
the tributaries are dry except during periods of heavy pre-
cipitation and spring runoff. The rolling uplands are deep-
ly dissected by the tributaries of Hanging Woman Creek,
and the terrain is especially rugged in T. 7 and 8 S., R. 43 E.
Stands of ponderosa pine are sparse along the steep sides
of the valleys; native grasses cover the ridges.

   The principal land  use is livestock grazing, but  some
hay is raised in meadows along the flood plain of Hanging
Woman Creek and a few of its tributaries.

               GEOLOGIC STRUCTURE

   The Anderson coal bed dips to the south, and minor
reversals  seem to have affected the  topography. Slight
synclinal  flexures along Hanging Woman Creek and the
divide to the east plunge gently southward.

   Displacement on two northeast-trending faults down-
thrown to the southeast seemingly is less  than 100 feet.
The faults may extend farther than  shown, particularly
between drill hole SH-23 in sec. 26, T. 9 S., R.43 E., and
drill hole SH-24 in sec. 35 of that  township. An east-
trending fault is alongPK Creek, in T. 8 S., R. 42 and 43 E.,
downthrown on the north.

                     COAL BEDS

   The names applied to the coal beds in the  Hanging
Woman Creek coal field are those used by Baker (1929).
They include the Roland, Smith, Anderson, Dietz, and
the Canyon beds. Several other coal beds lie below the
Canyon bed. A complete stratigraphic section (PI. 33,
Section D-M) is shown on the gamma log of an oil well in
NEVA sec. 36, T. 9 S., R. 42 E. This log shows the Roland
bed as 9  feet thick and 291 feet above the Smith bed,
which is 8 feet thick. The Smith bed is 148 feet above
the Anderson bed, which is 31 feet thick; the Anderson
bed is 122 feet above the Dietz No. 1 bed and 145 feet
above the Dietz No. 2 bed, each of which is only 4 feet
thick. Three coal beds about 230 feet below the Anderson
bed have  thicknesses of 6 feet, 3 feet, and 8 feet, and are
separated by 10-foot partings. The Canyon coal bed is 13
feet thick and is about 300 feet below the Anderson. The
Wall coal  bed, 140 feet below the top of the Canyon coal
bed, consists of three benches. The top one is 9 feet thick,
                        the middle one 6 feet, and the lower one 4 feet. The
                        upper parting is 6 feet and the lower is 16 feet. This log
                        correlates well with the gamma logs of an oil well in
                        SWttsec. 17,T.9S.,R.44E.

                          The  Anderson  coal bed is  burned over much of the
                        area, especially where overburden is less than 50 feet
                        thick (PI. 9). Nevertheless, it is the most important bed in
                        the Hanging  Woman Creek area because it maintains its
                        thickness and consistent quality. Subsurface correlation
                        of the Anderson bed is relatively easy because of its thick-
                        ness  and its  distinctive curve  on bore-hole geophysical
                        logs.  The thickness ranges from 15 feet in drill hole SH-
                        23, sec. 22, T.9 S., R. 43 E., to 36 feet in drill hole SH-3,
                        sec.3,T.8S.,R.44E.

                          The  Dietz coal bed (PI. 9) crops out along the sides of
                        the valleys of Hanging Woman Creek and its tributaries
                        in the northern part of the area. In places, the bed has
                        burned and produced clinker,  especially in the northern
                        part of the area where the bed is thickest. The maximum
                        thickness of  18 feet was penetrated in drill hole SH-10,
                        sec. 31, T. 7 S., R. 44 E.; in drill hole SH-18 in sec. 22,
                        T. 9  S., R. 44 E., it has a thickness of 10 feet. In the
                        southwestern part of the area, the Dietz bed consists of
                        two benches, each 4 feet thick, separated by as much as
                        30 feet of parting.

                          Strippable reserves  in the Dietz coal bed over large
                        areas are covered with clinker produced by burning of
                        the overlying Anderson coal bed. The vertical  distance
                        between the  Dietz and the Anderson bed (PI. 9) is 50 to
                        70 feet in a large part of the area. Although it is 70 feet
                        in a large part of T. 9 S., R. 44 E., it decreases westward
                        to 60 feet, then increases to 100 feet in T. 9 S.,  R. 42 E.
                        This  is  the area where the Dietz coal bed splits and thins
                        appreciably.  In most places where the Anderson bed has
                        not burned, it is about 100 feet above the Dietz bed. For
                        this reason, Strippable reserves in the Dietz bed have been
                        shown as far as the trace of the unburned Anderson coal
                        bed.  In  certain areas,  such as the East Fork and Main
                        Fork of Trail Creek, the Dietz coal bed could be recovered
                        economically as  far back  as the Anderson  overburden
                        limit of 50 feet. Information on the Dietz bed  is not as
                        plentiful as for the Anderson bed. One or more  silicified
                        layers about  2 to 4 feet thick hampered drilling between
                        the Anderson and the  Dietz coal beds. Also, very heavy
                        white clay encountered in drill hole SH-23, sec. 22, T. 9 S.,
                        R. 43 E., tended to plug the drill pipe.

                                           COAL QUALITY

                          Several core samples were obtained from the Hanging
                        Woman  Creek coal field and  were analyzed. Proximate

-------
                                   INDIVIDUAL DEPOSITS—WEST MOORHEAD
                                                                                                        57
analysis, forms of sulfur, and heating values are shown in
Table 26. Where multiple core samples were obtained
from a coal bed in a drill hole, they were combined prior
to analysis for major ash constituents (Table 27).


                  COAL RESERVES

   Coal reserves in  the Hanging Woman Creek area have
been calculated for both the  Anderson and Dietz coal
beds (Table 25).

   Reserves in the Anderson coal bed total 1,583,290,000
tons, and in the Dietz coal bed, 1,120,960,000 tons.


         WEST MOORHEAD COAL DEPOSIT

                     LOCATION

   The West Moorhead coal field, in T. 7 S.,  R. 46 and
47 E., T. 8 S., R. 45,46, and 47 E., and the north half of
T. 9 S., R. 45, 46, and 47 E., Powder River County (PI.
10A, B, and C), is limited on the east by the steep slope
of the Powder River valley, on the south and west by
high ridges,  and on  the north by  clinker areas of the
burned Anderson and Canyon coal beds. The area borders
the Hanging Woman Creek coal field (PI. 9) to the west
and the Diamond Butte (PI. 19), Goodspeed  Butte (PI.
20), and Fire Gulch (PI. 21) coal fields to the north.


         FIELD WORK AND MAP PREPARATION

   Most of the field work for this report was done during
the summer  of 1968, but in 1969 and  1970 some addi-
tional holes were drilled. The field method used for evalu-
ation of strippable  coal in the West Moorhead coal field
was developed for areas where adequate topographic maps
were not available  (Carmichael, 1967). It included the
establishment  of temporary  benchmarks  by  leveling
throughout the area for topographic control. These bench-
marks then served as base stations for altimeter surveys
by which hundreds of altimeter altitudes were measured
and plotted on aerial photos concurrently with mapping
of the coal outcrops, clinker, and contacts between the
burned and unburned areas. Drilling was carried out on a
reconnaissance basis to determine coal thickness and
depth; cores were taken for analysis of coal quality.

   Modifications of the method by Montana  Bureau  of
Mines and Geology included use of a Paulin microbaro-
graph for recording variations in atmospheric pressure,
and use of a computer program to correct altimeter read-
ings for changes in temperature and pressure.
             PREVIOUS GEOLOGIC WORK

   The West Moorhead coal  field was described in an
open-file report by the US. Geological Survey (Bryson
and Bass, 1966), and in a Montana Bureau of Mines and
Geology bulletin (Matson, 1971).

                  LAND OWNERSHIP

   Sec. 16 and 36 of each township were granted to the
State of Montana for school land, and the state has gen-
erally retained the mineral rights. In the other sections of
each  township, the Federal Government generally re-
tained the coal rights  and some  of the other mineral
rights, but most of the surface is privately owned.

         SURFACE FEATURES AND LAND USE

   The topography is characterized by long smooth ridge
tops, sharp breaks along the slopes of the ridges, and the
deeply incised valleys of tributaries of Otter Creek.

   Although  a small part of the area is cultivated and
some  hay is raised in  many of the valleys, most of the
area is suitable only for livestock grazing. Ponderosa pine
thinly veils much of the northern part of the area, es-
pecially along the steep sides of the valleys.

               GEOLOGIC STRUCTURE

   The regional dip of the strata is southwestward,  but
reversals are numerous in shallow anticlinal and synclinal
structures.

   Two west-trending faults were mapped by  Bryson and
Bass (1966), one in the northern part of sec. 13, T. 8 S.,
R.46 E., and sec. 18, T.8 S., R.47 E., and another in the
north-central part of T.  8 S., R.45 E.The maximum rela-
tive vertical displacement observed on the Anderson coal
bed in sec. 13, T.8 S.,R.46 E., is about 60 feet. Displace-
ment  of the Anderson  coal bed by the  fault in T. 8 S.,
R. 45 E., is about 40 feet.

   The dominant structural features are shallow anticlines
and syndines in the eastern two-thirds of the mapped
area, where dips are about 1  degree (PI.  10A and C). A
pronounced  structural high in  sec. 17, 18, 20, and 21,
T. 8 S., R. 47 E., is south of the west-trending faults in
that township.

   The structural contours on the Canyon and Anderson
beds show the variation in the stratigraphic separation of
these two coal beds. The vertical distance between these
coal beds is at a minimum, 120 feet, in the southern part

-------
58
                   STRIPPABLE COAL. SOUTHEASTERN MONTANA


Table 28.-Reserves, overburden, oveibuiden ratio, acres, and tons/acre, West Moorhead coal deposit.
                                      ANDERSON, DIETZ, and CANYON BEDS
   Thickness of
  overburden, ft.
   Indicated reserves,
      million tons
     Overburden,
    million cu. yd.
   Overburden ratio,
   cubic yards/ton
         Acres
                   Tons/acre
      Oto  SO
     SO to 100
    100 to 150
               Total
        317.77
        991.41
        662.24
      1,971.42
        725.95
       3,594.12
       3.899.28
Total   8,219.35
        2.28
        3.62
        5.88
Average  4.16
Total
13,632.0
29,702.4
19.289.6
62,624.0
        23,310.6
        33,378.6
        34.331.4
Average  31,480.2
                                                ANDERSON BED
      Oto  50
     50 to 100
    100 to 150
               Total
                               76.5
                            1,268.6
                            1.571.3
                      Total  2,916.4
                            1.15
                            2.71
                            4.47
                    Average  3.30
                          1,433.6
                         10,483.2
                          7.744.0
                 Total    19,660.8
                            46,003.1
                            44,512.1
                            45.347.4
                    Average  44,949.3
                                                   DIETZ BED
      Oto  50
     50 to 100
               Total
        217.81                 595.61               2.73
        179.68                1.116.68               6.21
        397.49         Total   1,712.29      Average  4.30
                                             11,187.2
                                              9.228.8
                                    Total    20,416.0
                                             19,469.5
                                             19.469.4
                                    Average  19,469.5
                                                  CANYON BED
      Oto  50
     50 to 100
    100 to 150
               Total
                               53.84
                             1,208.84
                             2.327.98
                      Total   3490.66
 of T. 8 S., R. 47 E. It increases westward to the maxi-
 mum of 240 feet and increases northward to about 200
 feet.

                      COAL BEDS

    Although coal beds are numerous in the mapped area,
 only the Canyon, Dietz, and Anderson beds offer pros-
 pects for commercial development. These beds correlate
 with beds of the same name in the Hanging Woman Creek
 area (Pi. 33, Section D-M). Other coal beds in the area in-
 clude the Smith bed, which is 110 to 150 feet above the
 Anderson coal bed, and the Roland bed. The Smith bed
 is thin, and in the western part of the mapped area it con-
 tains numerous petrified tree stumps, many of which are
 in an upright position. The Roland coal bed, mapped just
 south  of the  study area, is about  200 feet above the
 Smith bed (Bryson and Bass, 1966).
                            1.58
                            340
                            7.48
                    Average  5.2
                 Total
          1,011.2
          9,990.4
         11445.6
         22447.2
                    33,633.3
                    34444.2
                    26.942.7
           Average  30,611.1
                                              The Anderson coal bed  (PI. 10A)  is 40 to 81  feet
                                           above the Dietz bed except in sec. 27, T. 8 S., R. 47 E.,
                                           where  in  drill  hole  SM-4C  the  distance  from the
                                           base  of the  Anderson to the top of the  Dietz is only
                                            13 feet. This is also the area where the distance between
                                           the Anderson and the  Canyon beds reaches its mini-
                                           mum  of 120 feet. Thickness of the Anderson bed ex-
                                           ceeds 24 feet except  in  the extreme south-central part
                                           of the mapped area (PI. 10A). At the western edge of
                                           the area, the  Anderson bed is 30 feet thick in drill hole
                                           SM-19, sec. 33, T. 8 S., R. 45 E. In the eastern part of
                                           the area, it is 29 feet thick in drill hole SM-4, sec. 27,
                                           T. 8  S., R. 47 E. The area of thinning is believed to be
                                           confined to  the  vicinity of  sec. 16, T. 9 S., R.  46 E.,
                                           where the coal is 14 feet thick in drill hole SM-15. Whereas
                                           only  Ifc miles northeast in drill hole SM-11, sec. 11,
                                           T.9 S., R.46 E., the bed is 29 feet thick.

-------
                                       Table 29.-Proximate analysis, forms of sulfur, and heating value, West Moorhead coal deposit.
 Drfllhote
and location
SH41
7S R46E S33
BDAC
                                                                               iximate.'
Form of tulfur
SH-62
8S R46E S3
BDBB
SH-64
7SR46ES10
DCBC

SH-7041
8S R4SE S28
DAAD
SH-7042
8SR4SES1S
BBDD

SH-7043
8S R4SE S24
BAAA
Depth
sampled

125 to
134ft.
134 to
143 ft.

143 to
147 ft.

78 to
85 ft.

85 to
89ft.

48 to
50ft.

59 to
68ft.

68 to
69ft.

198 to
208ft.

130 to
142 ft.
43 to
52ft.

52 to
55ft.

132 to
140ft

140 to
148 ft.
148 to
153ft.
Lab.
number


134
135


136

137


138


139


220


221


222


223

228


225


226


224

227
Coal
bed
Canyon






Canyon




Cook


Dietz





Canyon


Canyon


Dietz




Canyon







Form of
analysis
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
«
l/ Moisture
26.660

26.990

26.450


24.230

25.670


30.800


31.200


30.050


29.860


29.980


32.430

31.650


32.180


33.450

31.350


Volatile
matter
31.323
42.710
46.177
30.383
41.615
44.533
29.305
39.843
46.104
32.520
42.920
46.372
30.658
41.245
45.367
29.889
43.192
45.238
30.887
44.895
47.717
29.442
42.091
45.528
29.057
41.427
43.764
30.792
43.976
46.063
29.544
43.724
46.329
28.996
42.424
44.614
28.067
41.385
43.837
26.576
39.933
42.017
26.486
38.581
44.802
Fixed
carbon
36.509
49.781
53.823
37.843
51.833
55.467
34.258
46.577
53.896
37.609
49.636
53.628
36.919
49.669
54.633
36.181
52.285
54.762
33.843
49.191
52.283
35.226
50.359
54.472
37.338
53.233
56.236
36.056
51.494
53.937
34.226
50.653
53.671
35.997
52.666
55.386
35.959
53.021
56.163
36.674
55.108
57.983
32.633
47.535
55.198

Ash
5.507
7.509
4.784
6.552

9.988
13.580

5.640
7.444
6.753
9.086

3.130
4.524

4.069
5.915

5.282
7.551

3.745
5.340

3.172
4.530

3.800
5.623

3.357
4.911

3.794
5.594

3.300
4.958
9.531
13.884


Sulfur
.295
.403
.435
.323
.442
.473
1.383
1.880
2.175
.245
.324
.350
.415
.558
.613
.151
.218
.228
.315
.458
.486
.386
.552
.597
.092
.131
.139
.138
.197
.206
.660
.977
1.035
.311
.455
.478
.228
.336
.356
.177
.266
.280
1.247
1.817
2.109

Sulfate
.017
.024
.026
.034
.047
.050
.049
.066
.077
.035
.046
.050
.043
.058
.064
.024
.034
.036
.015
.022
.024
.015
.022
.024
.000
.000
.000
.000
.000
.000
.023
.034
.036
.023
.034
.036
.023
.034
.036
.015
.022
.023
.022
.032
.038

Pyritic
.104
.142
.154
.076
.105
.112
.447
.608
.704
§1
1
7
2
.070
.077
.040
.057
.060
.069
.100
.107
.085
.121
.131
.038
.055
.058
.031
.044
.046
.123
.182
.193
.062
.091
.096
.121
.179
.190
.074
.111
.117
.423
.616
.716

Organic
.174
.237
.256
Si
.311
.887
1.205
1.395
.149
.197
.212
.320
.430
.473
.087
.126
.132
.230
.335
.356
.286
.408
.442
.054
.077
.081
.107
.153
.160
.514
.761
.806
.225
.330
.347
.083
.123
.130
.089
.133
.140
.802
1.168
1.356
Heating
value (Btu)
8379
11425
12352
8281
11343
12138
7534
10243
11853
8462
11169
12067
8029
10802
11881

7948
11486
12030

7907
11492
12214
8007
11446
12381
7970
11363
12004
8241
11769
12328
8080
11957
12670
7966
11655
12257
7826
11539
12223
7523
11304
11894
7419
10807
12549













S
o
<
3
C
>
r
o
n
•«
o
CO
5
7
1
m
H
s
o
jfl

>
O













 /A, at received; B, moisture free;C, moisture and ash free.

-------
                                            Table 30.-Proximate analysis, ultimate analysis, and heating value, West Moorhead coal deposit.
                                                                                                                                            s
  Drillhole
 and location
 SM-4
 8S 47E S27
 BCAB

 SM-1S
 9S 46E S16
 BADC

 SM-18
 8S 4SE S23
 CDAC

 SM-1A
 7S 47E S16
 BDC

 SM-13
 8S46ES16
 CDCC
 Drillhole
and location
SM-4
8S 47E S27
BCAB

SM-1S
9S46ES16
BADC

SM-18
8S 45E S23
CDAC

SM-1A
7S 47E S16
BDC

SM-13
8S46ES16
CDCC
 Depth
 sampled
  86 to
 115ft.
 64 to
 78ft.
 52 to
 83ft.
 80 to
 98ft.
 84 to
103 ft.
 Depth
sampled
 86 to
115ft.
 64 to
 78ft.
 52 to
 83ft.
 80 to
 98ft.
 84 to
103 ft.
  Lab.
 number
J-6243



J-6245



J-6246



J-6242



J-6244
  Coal
  bed
Anderson



Anderson



Anderson



Canyon



Canyon
 Form of 1
 analysis  /
   A
   B
   C

   A
   B
   C

   A
   B
   C

   A
   B
   C

   A
   B
   C
Proximate. %
Moisture
27.2

28.6


22.9


29.7

23.4






Volatile
matter
31.5
43.3
46.6
29.4
41.2
45.5
32.5
42.2
44.6
29.9
42.6
45.1
32.3
42.2
44.4




Fixed
carbon
36.2
49.7
53.4
35.3
49.4
54.5
40.4
52.4
55.4
36.4
51.7
54.9
40.4
52.7
55.6




Ash
5.1
7.0

6.7
9.4

4.2
5.4

4.0
5.7
3.9
5.1





S
0.4
0.6
0.6
0.4
0.5
0.6
0.3
0.4
0.4
0.3
0.4
0.4
0.2
0.3
0.3




H
6.4
4.6
4.9
6.4
4.5
4.9
6.1
4.6
4.8
6.5
4.6
4.9
6.1
4.6
4.9




Ultimate, %
C N
49.3 0.9
67.7 1.2
72.9 1.3
47.5
66.6
73.5
52.7
68.4
72.3
48.4
68.8
73.0
.0
.4
.5
.1
.4
.5
.0
.4
.5
53.4 1.0
69.8 1.4
73.5 1.4







Heating
O value (Bni)
37.9 8150
18.9 11210
20.3
38.0
17.6
19.5
35.6
19.8
21.0
39.8
19.1
20.2
35.4
18.8
19.9




12060
7950
11130
12280
8790
11410
12060
8070
11470
12170
8920
11650
12280











H
•3
§5
t«
w
o
o
CO
0
                                             Table 31.-Grindability, forms of sulfur, and fusibility of ash, West Moorhead coal deposit.
                                                                          Form of sulfur. %
 Lab.
number
J-6243



J-6245



J-6246



J-6242



J-6244
 Coal
 bed
Anderson



Anderson



Anderson



Canyon



Canyon
Form of i   Hardgrove
analysis  /  grindability
A
B
C

A
B
C

A
B
C

A
B
C

A
B
C
43



43



45



39



43
Sulfur
.40
i6o
.36
.50
.55
.30
.39
.41
.31
.38
.40
.25
.32
.33
Sulfate
.01
.02
.02
.01
.02
.02
.03
.04
.04
.01

.00
.02
.02
.02
Pyritic
.01
.01
.01
.01
:o°{
.03
.04
.04
.03
.00
.00
.01
.01
.01
Organic
.38
.53
.57
.34
.47
.52
.24
.31
.33
.27
.38
.40
.22
29
.30
                                                                                                                                 Fusibility of n*h  F
                                                                                  Initial
                                                                                deformation   Softening    Fluid
                                                                                  temp.         temp.     temp.
                                                                                                            2350
                                                                                                            2010
                                                                                                            2480
                                                                                                            2400
                                                                                                           2470
                                                                                                              2410
                                                                                               2050
                                                                                               2530
                                                                                               2450
                                                                                                          2460
                                                                                              2090
                                                                                              2570
                                                                                              2500
                                                                                                                                 S

                                                                                                                                 CO
93
Z

O
z
H
                                                                                               2520      2570
I/A, as received; B, moisture free; C, moisture and ash free.

-------
                                                     Table 32.-Major ash constituents, West Moorhead coal deposit
 Drill hole
and location
SM-1A
7S47ES16
BDC

SM-4
8S 47E S27
BCAB

SM-13
8S46ES16
CDCC

SM-1S
9S46ES16
BADC

SM-18
8S45ES23
CDAC

SH-61
7S 46E S33
BDAC

SH-62
8S 46E S3
BDBB

SH-7041
8S 4SE S28
DAAD
SH-7042
8S4SES15
BBDD

SH-7043
8S 4SE S24
BAAA
 Depth
sampled
  80 to
  98ft.
  86 to
 115 ft.
  84 to
 103 ft.
  64 to
  78ft.
  52 to
  83ft.
 125 to
 147 ft.
  78 to
  89ft.
  59 to
  69ft.

 198 to
 208 ft.
 130 to
 142 ft.
  43 to
  55ft.

 132 to
 153 ft.
  Lab.     Coal                                                    Constituent, %
sample    bed      A12O3   CaO  Fe2O3   K2O    MgO  Na2O    P2OS     SiO2    SO3  TiO2    H2O
                     Canyon      12.6     29.2   7.2      .66      8.6    7.9      .77     17.2     14.1    .73     .55
J-6242
J-6243
J-6244
J-6245
J-6246
134-136
137-138
220-221
                          222
223
225,228
                     Canyon
                     Dietz
                     Dietz
                                                                                                  FeO  MnO  CO2  Total


                                                                                                   .28   .12  <.05    99.96
Anderson     13.4    25.8   7.5      .28      7.1   5.9      .62     18.9      17.3   1.1      .96      .20    .09    .30    99.45



Canyon       11.2    29.3   6.5      .39      8.3   8.8      .64     16.4      15.7    .65     .69      .08    .09    .60    99.34
                     Anderson     15.5     18.4   3.5     1.3        6.0    2.7      .98     35.7     11.6    .93     .68     1.6     .06
                     Anderson     12.2   27.0   5.8      .34      8.4    2.4     1.00     14.4     27.4    .72     .30      .32   .06
                     Canyon      12.1     15.6   6.8     1.0       5.8    2.2      .3      39.7     11.2    .5
                      11.2    19.3   5.7     1.0
                                             7.3    1.1      .4      40.7     11.9    .6
                      12.2    27.7   6.3      .3       9.9   3.6     1.9       20.5      15.5   .6
         Canyon       12.1    24.2   6.3      .4       6.1  10.0     1.3       28.4       8.1   .7


         Canyon       12.4    32.2   7.1      .3       8.1.   9.7      .7       14.9       9.7   .5
                      12.1    23.5   6.9      .2       10.8    1.6     1.7      13.4     25.7   .4
                          226,     Canyon       12.7    19.6   6.9      .8        5.2   9.4     1.0      27.8      18.1    .5
                          224,227
                                                                                                                                     O
                                                                                                                        .20    99.15  >
                                                                                                                                     f
.10  100.44  g

             T
      95.2   w
             v>
             H
             S
      99.2   O
             «fl
             a
             £
      98.5   D
                                                                                                                      97.6


                                                                                                                      95.6



                                                                                                                      96.3



                                                                                                                     102.0

-------
62
STRIPPABLE COAL, SOUTHEASTERN MONTANA
   Thickness of the Canyon coal bed (PL  IOC) ranges
from  17  to 24 feet and averages 18 feet in the eastern
two-thirds and 22  feet in the western one-third of the
mapped area. A coal bed 2 to 5 feet thick lies about 5
feet above the Canyon in the eastern two-thirds of the
area but is absent in the western one-third.

   The Dietz coal bed (PI. 10B), 67 to 122 feet above the
Canyon bed and 40 to 81 feet below the Anderson coal
bed, ranges in  thickness from 5 to 11 feet, but seems to
be thinner or absent in T. 7 S., R. 47 E.

                   COAL QUALITY

   Twenty  core samples were recovered during drilling
programs in 1968,1969, and 1970. Proximate, ultimate,
ash fusibility,  sulfur forms, and grindability analyses of
five cores obtained in 1968 were  performed by the U.S.
Bureau of Mines, Pittsburgh Coal Research Center (Tables
30, 31). Proximate analyses of cores obtained in 1969
and 1970 were made in the Montana Bureau of Mines and
Geology analytical laboratory (Table 29). Major ash con-
stituents of the core samples obtained in 1968 were de-
termined by the U.S. Geological Survey, Washington, D.C.;
those in the cores obtained in 1969 and 1970 were deter-
mined by the Montana Bureau of Mines and Geology ana-
lytical laboratory (Table 32).

                  COAL RESERVES

   The strippable reserves in the West Moorhead coal field
total  1,971,420,000 tons. The Anderson bed contains
the largest reserves, 883,740,000  tons, the Canyon con-
tains 690,190,000 tons, and the Dietz 397,490,000 tons.

  POKER JIM CREEK-O'DELL CREEK COAL DEPOSIT

                     LOCATION

    The Poker  Jim  Creek-O'Dell Creek coal deposit is in
T. 3 through 6 S., R. 42 through 45 E., Rosebud County
 (PI. 11A and  B). The north end of the area is 3 miles
 south of the  community of Ashland, and the  western
 boundary of the deposit is the Tongue River. The south-
 ern boundary is near Birney, where the overburden be-
 comes excessive, and the eastern boundary is the high di-
 vide between the Tongue River and Otter Creek. The area
 is between the Ashland (PI. 13A) and Otter Creek (PI. 12)
 coal  deposits  to the north  and the Birney coal deposit
 (PI. 7) to the south.

          FIELD WORK AND MAP PREPARATION

    Field work in the Poker Jim Creek-O'Dell Creek coal
 deposit  was begun in 1969; further drilling in 1970 ex-
                        panded the data base. Geologic mapping on black-and-
                        white  aerial photos fixed the boundaries of the clinker
                        produced by burning of the Knobloch coal bed. Private
                        company drill holes and  logs of oil wells in the vicinity
                        helped in the preparation of maps of the Knobloch coal
                        bed. A cross section through the area is shown on Plate 34.

                                    PREVIOUS GEOLOGIC WORK

                          The area was mapped and described in a U. S. Geologi-
                        cal Survey report on the Birney-Broadus coal field (War-
                        ren, 1959). Ayler, Smith, and Deutman (1969) included
                        the Knobloch deposits in their report on the  strippable
                        coal reserves in Montana.

                                         LAND OWNERSHIP

                          The land surface in the Poker Jim  Creek-O'Dell Creek
                        coal deposit is owned by individuals, the State of Mon-
                        tana, and the Federal Government. The administration of
                        the  federally-owned land is divided between the U.S.
                        Bureau of Land Management and the  U.S. Forest Service.
                        Some strippable coal in the northern  part of the area lies
                        within the Custer National Forest (PL 1 IB). The owner-
                        ship of the coal is divided between the Federal Govern-
                        ment, Burlington Northern, Inc., the State of Montana,
                        and some individuals. The railroad owns the coal on the
                        odd-numbered  sections outside the Custer National For-
                        est and has, in general, conveyed the surface but retained
                        the coal.

                                 SURFACE FEATURES AND LAND USE

                          The Tongue River has formed a  wide valley in the
                        area, and the strippable coal lies on the  east side of the
                        valley. The terrain slopes gently toward the Tongue River
                        and, in the northern part of the area,  toward the areas of
                        clinker formed by the burning of the underlying Knobloch
                        coal bed, but the clinker forms steep slopes and cliffs.

                          Many higher coal beds have burned to form clinker,
                        which caps knobs and borders the high ridges to the east.
                        In the north-central part of the area, O'Dell  Creek has
                        cut a valley approximately fc mile wide. Other tributaries
                        of the Tongue  River are generally short and steep. Hang-
                        ing Woman Creek, at the  south end of the area, has also
                        cut a prominent valley.

                          The principal land use in the area  is livestock grazing.
                        Hay is raised on meadows on the flood plain of the Tongue
                        River, along O'Dell Creek, and along Hanging Woman
                        Creek.

-------
                               INDIVIDUAL DEPOSITS—POKER JIM CREEK-O'DELL CREEK
                                                                                                             63
          Table 33.-Reserves, overburden, overburden ratio, acres, and tons/acre, Poker Jim Creek-O'Dell Creek coal deposit
                                           KNOBLOCH BED-PLATE 11A
Thickness of
overburden,!*.
Oto SO
50 to 100
100 to 150
150 to 200
Indicated reserves,
million tons
110.10
122.71
111.94
28.54
               Total    373.29
Overburden and
inteiburden,
million cu. yd.
268.17
401.60
438.31
133.88
al 1,241.96
Overburden and
interburden ratio,
cubic yards/ton
2.43
3.27
3.91
4.69
Average 3.32 I
                                                                       Total
                                                                                Acres
                       3,040
                       2,566
                       1,824
                        460
                       7,890
Average
                                         Tons/acre
36,217.1
47,821.5
61,370.6
62.043.5
47,311.8
                                          KNOBLOCH-PLATE 11B
Thickness of
overburden, ft.
Oto 50
50 to 100
100 to 150
150 to 200
200 to 250

Indicated reserves,
million tons
8.66
60.66
194.72
198.79
101.95
Total 564.78
                                    Total
               GEOLOGIC STRUCTURE

   The strata in the Poker Jim Creek-O'Dell Creek area
are nearly horizontal, but local dips and rises are numer-
ous. In the northern  part of the area, the Knobloch coal
bed is some distance above river level, and in the western
part of T. 5 S., R. 43 E., it crops out at river level. The mid-
dle bench of the Knobloch is approximately 100 feet be-
low surface at Birney.

                    COAL BEDS

   The Knobloch is the only coal bed in the Poker Jim
Creek-O'Dell Creek area that is strippable. The King bed
is 40 to 200 feet above the Knobloch. Other beds in the
divide between Tongue River and Otter Creek are the
O'Dell, Pawnee, Wall, Cook, Dunning, Canyon, and And-
erson beds, but none of these were mapped for this re-
port. The Knobloch coal bed was named for the Knob-
loch ranch in sec. 17, T. 5 S., R. 43 E.

   The Knobloch coal bed is a single seam along the north
end of the Poker Jim Creek-O'Dell Creek area (PI.  11B),
but the  center of the area and farther south the Knob-
loch is split into three  benches. In the northern part of
the area, the  Knobloch is as much as 60 feet thick, as
Overburden,
million cu. yd.
5.79
92.15
509.98
709.66
464.64
U 1,782.22
Overburden ratio,
cubic yards/ton
0.66
1.51
2.61
3.55
4.55
Average 3.15 1
                                                                       Total
                                                                                Acres
                        108.8
                        761.6
                       2,508.8
                       2,528.0
                       1.280.0
                       7,187.2
Average
                                         Tons/acre
79,595.6
79,648.1
77,614.8
78,635.3
79.648.4
78,581.4
measured in drill hole SH-7055, sec. 6, T. 4 S., R. 45 E. In
drill hole SH-7059, sec. 34, T. 3 S., R.44 E., only 14 feet
of the coal was drilled, owing to lost circulation. In drill
hole SH-7058, sec. 22, T. 4 S., R. 44 E., the Knobloch is 42
feet thick, but in the southern part of T. 4 S., R. 44 E., (PI.
11B, 34), the Knobloch begins to split into three benches.
In drillhole SH-100, sec. 5,T.5 S., R.44 E.,the upper and
middle benches have a combined thickness  of 27 feet,
and the lower bench, 50 feet below, has a thickness of 5
feet. The main bed splits again in the northern part  of
T. 5 S., R. 43 E., to form the upper and middle benches.
The upper bench is 7% feet thick in DH-3, sec. 16, T. 5 S.,
R. 43 E., and 9 feet thick in drill hole SH-101, sec. 20,
T. 5 S., R. 43  E., where it is 29 feet above  the middle
bench, which is 18 feet thick. In an abandoned mine in
the SE& sec. 19, T. 5 S., R. 43 E., the upper  bench is al-
most  12 feet thick. The 14-foot parting below it consists
of 6 feet of claystone and 8 feet of sandstone overlying
the middle bench, which is 20 feet thick. In drill hole SH-
117 in sec. 30 of the same township, the upper bench is
8 feet thick and the one below it is 20 feet thick. They
are separated by a  41-foot parting. In drill hole SH-103,
sec. 7, T. 6 S., R. 43 E., a carbonaceous zone  about 52
feet above the main bench is presumed to correlate with
the upper bench of the Knobloch. In this  drill hole the
middle bench is 12 feet thick, and the lower bench is 13

-------
                                        Table 34.-Proximate analyci», fornu of culfui, and heating value, Poker Jim Creek-O'Dell Creek ooal deposit.
                                                                                Proximate,
                                                                                                               Form of sulfur, %
  null hole
and location
SH-7058
4S R44F. S22
AIH'H

SH 705<>
.IS R44I Sl-t
DBBD
SH-IOO
SS R44I
AHAA
S.S
sn-io.i
65 R4.M S7
CDAD

SH 117
SS R43F S30
BACD

SH-705S
4S R4SE S6
DDBA
             Depth
            umpled
            W to
            Ml ft.
            2(H) to
            202ft.
            i :.s to
            105 to
            112ft.
             60 to
             66 ft.
            216 to
            218 ft
 Lab.
number
 269
 270
                         158
 142
 153
 265
 Coal
  bed
                                   Knobloch
                                   Knobloch
           Knobloch
           (U4M)
                                                       l-'orm of
1,
              A
              B
              C

              A
              B
              C

              A
              I)
              r
Knobloch      A
   (M)        B
              C

Knobloch      A
   (U)         B
              C

Knobloch      A
(U&MAL)    B
              C

Moisture
25.380


26.510


22.500


21.720


22.560


26.320


Volatile
matter
30.906
41.418
44.070
29.863
40.635
42.771
29.007
37.428
40.235
31.308
39.995
43.257
29.278
37.808
40.293
29.855
40.519
44.361
Fixed
carbon
39.223
52.564
55.930
39.958
54.372
57.229
43.088
55.597
59.765
41.068
52.464
56.743
43.386
56.025
59.707
37.444
50.820
55.639

Ash
4.491
6.019

3.669
4.993

5.406
6.975

5.903
7.541

4.776
6.168

6.381
8.661


Sulfur
.150
.201
.213
.095
.129
.136
.201
.259
.278
.163
.208
.225
.594
.767
.817
.154
.209
.229

Sulfate
.025
.033
036
.000
.000
.000
.017
.022
.024
.000
.000
.000
.080
.103
110
.000
.000
.000

Pyritic
.017
.022
.024
.017
.023
.025
.035
.045
.048
.018
.023
.025
.177
.229
.244
.024
.033
.036

Organic
.108
.145
.154
.078
.105
.111
.148
.191
.206
.145
.185
.200
.337
.435
.463
.130
.176
.193
 Heating
value (Btu)
                                                                                            9036
                                                                                           12109
                                                                                           12884

                                                                                            9005
                                                                                           12253
                                                                                           12897

                                                                                            8380
                                                                                           10813
                                                                                           11624

                                                                                            8963
                                                                                           11450
                                                                                           12384

                                                                                            9135
                                                                                           11797
                                                                                           12572

                                                                                            8558
                                                                                           11615
                                                                                           12717
U • Upper bench of Knobloch
M • Middle bench of Knobloch
L • Lower bench of Knobloch
 /A, as received; B. moisture free; C, moisture and ash free.

-------
                                                Table 35.-Major ash constituents, Poker Jim Creek-ODell Creek coal deposit.
Drill hole      Depth       Lab.         Coal
Constituent, %
and location

SH-7058
4S 44E S22
ABCB

SH-7059
3S 441 S34
DBBD

SH-100
5S 44K S5
ABAA

SH-103
6S43I S7
CDAD

SH-117
5S43I S30
BACD


SH-7055
4S 451 S6
DUBA
sampled


193 to
202 ft.


200 to
202 ft.


125 to
134 ft.


105 to
112ft


60 to
66ft.



216 to
2IK ft.
sample



269



270



158



142



153




265
bed A12O3 CaO Fe2O3 K2O MgO Na2O PaO5 SiO3 SO3 TiO2 Total

Knobloch 21.0 20.6 4.7 .2 3.7 9.8 .4 29.2 6.5 .6 96.7



Knobloch 23.5 21.6 4.4 .2 3.9 12.3 .6 25.1 5.3 .4 97.3



Knobloch 19.4 15.7 3.5 .2 3.3 10.8 .2 29.8 13.2 .6 96.7
(U&M)


Knobloch 26.5 8.1 2.6 .3 1.5 7.1 1.7 44.6 4.1 .7 97.2
(M)


Knobloch 14.3 12.8 9.2 1.2 3.2 7.0 .2 25.4 20.0 .5 93.8
(U)



Knobloch 22.0 15.0 2.7 .1 2.5 6.9 .7 39.8 4.9 .8 95.5
(U & M & L)

S
O
D
C
f
O
H
O
8
H
T
3
B
to
d
S
O
s
I
6
d
H
£
>a
H
n
PS


 U • Upper bench ..1 Knobloch
 M • Middle bench of Knobloch
 L, • Lower IMTK-II of Knobloch
                                                                                                                                                            in

-------
66
STRIPPABLE COAL, SOUTHEASTERN MONTANA
feet thick. These beds can be correlated with beds shown
on a log of an oil well in the NW& sec. 12, T. 6 S., R. 42 E.
(PI. 33 and 34).

                   COAL QUALITY

   Six core samples of the Knobloch coal bed were ana-
lyzed in the Montana  Bureau of Mines and Geology ana-
lytical laboratory for proximate analysis, forms of sulfur,
and heating value (Table 34), and major ash constituents
(Table 35).

                   COAL RESERVES

   All strippable reserves in the Poker Jim Creek-O'Dell
Creek coal deposit are in the Knobloch coal bed (Table
33).  The reserves  total 938,070,000  tons, comprising
564,780,000 tons.shown on Plate 11B and 373,290,000
tons shown on Plate 11 A.

           OTTER CREEK COAL DEPOSIT

                     LOCATION

   The Otter Creek coal deposit (PI. 12) is in T. 4 and 5 S.,
 R. 45 and 46 E.,  about 12 miles south of Ashland by
 road. The deposit is limited on the west, south, and  east
 by excessive overburden, and on the north it adjoins the
 Ashland (PI. 13A and B) and the Poker Jim Creek-O'Dell
 Creek (PI. 11A and B) coal deposits. To the southeast it
 borders the Diamond Butte (PI. 19) and Goodspeed Butte
 (PI. 20) coal deposits. It overlaps the Yager Butte (PI. 23A
 and B) coal deposit to the east.

          HELD WORK AND MAP PREPARATION

    The evaluation  of strippable coal in the Otter Creek
 area  was begun in  1967 when four holes were drilled on
 state-owned  land (Matson, Dahl, and Blumer, 1968). In
 1970 additional holes were drilled to extend the coal re-
 serves and to gather data for structural control to accu-
 rately determine the strippable reserves. Gamma logs of
 several oil wells were  helpful in developing the structural
 picture, as  well as for compiling the overburden maps.
 The  geology in the Otter Creek area was mapped during
 the summer of 1970 on  black-and-white aerial photos
 and during the winter of 1972 on color aerial photos.

              PREVIOUS GEOLOGIC WORK

    The Otter Creek area was included in a report on the
 Birney-Broadus area (Warren, 1959); in a report on strip-
 pable coal (Ayler, Smith, and Deutman, 1969); and in
 a  report  on strippable  coal deposits  on state lands
 (Matson, Dahl, and Blumer, 1968).
                                         LAND OWNERSHIP

                          The surface ownership in the Otter Creek area is di-
                       vided between private individuals, the State of Montana,
                       and the Federal Government. The State of Montana owns
                       the surface in sec. 16 and 36 of each township, and the
                       Federal Government has control of a few small tracts in
                       the east half of T. 4 S., R. 45 E., and the land within the
                       Custer National Forest. The rest of the surface is privately
                       owned.

                          The ownership of the coal on  state sections  remains
                       with  the  state; that  on  public lands  with the  Federal
                       Government. The Otter  Creek area is within the land
                       grant to Burlington Northern, Inc., which owns coal on
                       the odd-numbered sections outside the Custer National
                       Forest. The railroad has conveyed most of the surface but
                       has kept the coal rights from its original land grant. Some
                       coal along the Otter Creek valley is privately owned.

                                 SURFACE FEATURES AND LAND USE

                          The principal surface feature in the  area, Otter Creek,
                       is a northward-flowing tributary, which joins the Tongue
                       River at Ashland. Except in unusually dry years, it con-
                       tains water  all year, but it also has periods of  no flow
                       each year. The major tributaries of Otter Creek flow only
                       during periods of heavy precipitation and spring runoff.
                       Tributaries entering Otter Creek from  the east are long,
                       have gentle gradients, and occupy wide valleys. They head
                       near  the  top of  the divide between  Otter Creek and
                       Pumpkin  Creek to the east.  Tributaries entering Otter
                       Creek from  the west are shorter and steeper. Otter Creek
                       has deeply intrenched meanders; its present flood plain
                       is about a half mile wide. Clinker formed by the burning
                       of the underlying Knobloch coal  bed  borders the flood
                       plain and forms nearly vertical clinker banks in places. A
                       broad terrace, 100 to 150 feet above the present level of
                       Otter  Creek, has  been deeply dissected in places by the
                       tributaries of Otter Creek.

                          The principal land use  in the area is livestock grazing,
                       but grain and hay are raised in fields and meadows along
                       Otter Creek and its tributaries.

                                       GEOLOGIC STRUCTURE

                          Elevations obtained from drill  data on the top of the
                       Knobloch coal bed clearly show an anticline in the north
                       half of T. 5 S., R. 45 E. At its crest, the strata have been
                       uplifted about 80 feet above  their position in the south-
                       ernmost part of T.4S..R.45 E., and in the northern part
                       of T. 5 S., R. 45 E. The Knobloch bed is exposed about 30
                       to 40 feet above  stream level near the crest of the anti-

-------
                                      INDIVIDUAL DEPOSITS—OTTER CREEK
                                                                                                           67
                 Table 36.—Reserves, overburden, overburden ratio, acres, and tons/acre, Otter Creek coal deposit.
                                                 KNOBLOCH BED
   Thickness of
  overburden, ft.
    Indicated reserves,
      million tons
Overburden and
  interburden,
 million cu. yd.
  Overburden ratio,
   cubic yards/ton
         Acres
                   Tons/acre
      Oto  50
     50 to 100
    100 to 150
    150 to 200
    200 to 250
        241.77
        492.21
        535.42
        487.51
        318.64
Total   2,075.55
                                     Total
     275.52
     953.30
    U82.42
    1,454.34
    1.141.97
    5,407.55
        1.13
        1.93
        2.95
        2.98
        3.58
Average  2.60
Total
 3,686.4
 7,091.2
 7,352.6
 4,870.4
 2.790.4
25,791.0
Average
 65,591.4
 69,413.3
 72,820.5
100,104.7
114.207.9
 80,475.7
cline (Warren, 1959, p. 566). To the  north in sec.  16,
T. 4 S., R. 45 E., the Knobloch coal bed crops out near
stream level, and to the south, in the south half of sec. 26,
T. 5 S., R. 45 E., it dips below stream level. Although  the
information is inconclusive, because of scarcity of drill
data, the changes in thickness of the Knobloch coal bed
suggest  that the anticline, as a  structural feature, con-
trolled to some  extent  the deposition of the Knobloch
bed (PL 34, Section OC'-A'). The drill holes do show that
the Knobloch bed thins and begins to split on the north-
ern flank of the anticline, and the partings thicken  on  the
southern flank, where the lowest bench of the Knobloch
is either thin or missing.

                     COAL BEDS

   The Knobloch coal bed contains  the only strippable
reserves in the Otter Creek coal deposit. Other coal beds
include  the King bed, which is 70 to 160 feet above  the
Knobloch bed in T. 5 S., R. 45 E., and several  higher
beds, which are  exposed  along  the steep  slopes  of  the
ridges on both sides of Otter Creek.

   The thickest  coal section in the Otter Creek deposit
was  66  feet as measured  in drill hole SH-7054,  sec. 2,
T. 4 S., R. 45 E. Southward, the Knobloch bed thins grad-
ually; in drill hole SS-6, sec. 16, T. 4 S., R. 45 E., it has a
                                           thickness of 47  feet. The split begins to develop in the
                                           Knobloch coal bed in the southern part of T. 4 S., R. 45 E.,
                                           as shown in a log of an oil well in sec. 24 (PI. 34, Section
                                           OC'-A'), where the upper bench is 46 feet thick and the
                                           lower bench is  19 feet  thick. Both benches thin  south-
                                           ward, as shown by the isopachs (PL 12). In the northern
                                           part of T. 5 S., R. 45 E., the upper bench of the Knob-
                                           loch  splits  again and a  bench called the middle  bench
                                           appears. In about this same place, the lower bench thins
                                           and has not been traced farther south.

                                                              COAL QUALITY

                                             Core  samples from the Otter Creek coal  field were
                                           analyzed by the  Montana Bureau of Mines and Geology
                                           analytical laboratory, except  for one sample taken  in
                                           1967  from drill  hole SS-5, which was analyzed by the
                                           U.S. Bureau of Mines, Pittsburgh Coal Research Center.

                                             Proximate analysis, forms of sulfur, and heating value
                                           are shown  in Table  37,  and major ash constituents are
                                           shown in Table 38.

                                                              COAL RESERVES

                                             Strippable reserves in the  Knobloch coal bed  in the
                                           Otter Creek coal field total 2,075,550,000 tons (Table 36).

-------
                                             Ttble 37.-Proximate analysis, forms of sulfur, and heating value, Otter Creek coal deposit.
  Drill hole
 and location
 SI 1-7044
 SS R46E S30
 DDAD
SH-7045
SSR46ES20
CBBD
Sll-7049
SS R46E S2
DCDB
SH-705 1
4S R46h
CBBA
SH-705 2
5SR4SES27
BDAO
SH-705 3
4S R4SE S4
AAAA
Depth
sampled
178 to
l£7 ft.
187to
197ft.
197 to
199 ft.
60 to
65ft.
106 to
115ft.
115 to
124ft.
124to
127 ft.
177to
185 ft.
185 to
193 n.
!•».! to
117ft.
116 to
1 26 ft.
126lo
135 ft.
106 to
116 H.
116 to
126ft.
112 to
122ft.
Lab.
number
233
234
235
238
229
230
231
246
2-J7
248
250
251
253
254
255
  Coal
  bed
                                           Knobloch
                                                                                 pximate.
                                                                                                                     Form of mlfur. %
Knobloch
Knobloch
Rnobloch
Knobloch
Knobloch
Form of i
analysis /
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
Moisture
27.690


28.470


28.940


29.390


36.400


29.790


24.S60


26.900


29.S80


31.350



28.590


30.850


28.760


31.730


28.150


Volatile
matter
29.270
40.479
43.761
30.685
42.898
46.014
28.224
39.719
41.993
26.025
36.857
43.385
25.739
40.471
43.094
28.268
40.263
43.461
30.464
40.382
42.785
35.300
48.290
52.007
29.938
42.514
45.568
30.795
44.858
47.416

28.559
39.993
43.016
26.986
39.026
41.178
31.015
43.535
46.316
36.569
53.566
56.471
28.810
40.097
42.371
fixed
carbon
37.616
52.021
56.239
36.001
50.330
53.986
38.987
54.864
58.007
33.961
48.097
56.615
33.990
53.443
56.906
36.774
52.378
56.539
40.739
54.002
57.215
32.576
44.563
47.993
35.761
50.783
54.432
34.151
49.747
52.584

37.832
52.979
56.984
38.550
55.748
58.822
35.949
50.461
53.684
28.188
41.289
43.529
39.185
54.537
57.629
Ash
5.423
7.500

4.844
6.772

3.849
5.417

10.624
15.046

3.871
6.086

5.167
7.360

4.237
5.617

5.224
7.146

4.721
6.703

3.704
5.395


5.019
7.028

3.614
5.226

4.277
6.003

3.512
5.145

3.855
5.365

Sulfur
.157
.218
.235
.205
.286
.307
.190
.268
.283
5.320
7.534
8.869
.160
.252
.268
.178
.254
.274
.276
.366
.388
.225
.308
.331
.140
.198
.213
.219
.319
.338

.181
.254
.273
.169
.245
,258
.277
.389
.414
.219
.320
.338
.143
.199
.210
Sulfate
.000
.000
.000
.000
.000



.000
.126
.179
.210
.021
.033
.035
.023
.033
.036
.025
.033
.035
.018
.025
.026
.000
.000
.000
.000
.000
.000

.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.016
.022
.023
Pyritic
.008
.011
.012
.008
.011
§12
16
22
.024
4.295
6.083
7.161
.042
.066
.070
.046
.066
.071
.025
.033
.035
.045
.062
.066
.031
.044
.047
.030
.044
.047

.000
.000
.000
.015
.022
.023
.016

!024
.038
.055
.265
.016
.022
.023
Organic
.149
.206
.223
.197
.275
.295
.175
.246
.260
.898
1.272
1.498
.097
.153
.163
.108
.154
.167
.226
.300
.318
.162
.221
.238
.109
.154
.165
.189
.275
.291

.181
.254
.273
.154
.222
.235
.261
.367
.390
.181
.265
.279
.111
.155
.163
Heating
value (Btu)
8515
11776
12731
8399
11742
12595
8457
11901
12583
8011
11345
13354
7458
11726
12486
7961
11340
12240
8891
11786
12487
8261
11301
12171
8002
11364
12180
7831
11407
12058

8305
11631
12510
8283
11978
12638
8258
11592
12332
8129
11908
12554
8576
11936
12613










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SH-7053
4S R45E S4
AAAA
SH-7054
4SR45I S2
DBfX
SH-7055
4S K45KS6
ODBA

SH-7060
4« H4M. ',<:
\>\>f\<
\>M>\>
122 to
132 ft.

132 to
140 ft.

140 to
148 ft.

148 to
L56ft.

156 to
165ft.

165 to
171 ft.
 84 to
 94ft

 94 to
100 fl.

100 to
106 It
216 to
218ft
141 to
H'> ft.

)4'> to
151ft
 rif, to
 7711
                       Knobloch
 256


 257


 258


 259


 260


 261



 262


 263


 264



 265



 271


 272



I73JI9
                       Knobloch
                       Knobloch
                       Knobloch
                                            Knobloch
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

A
B
r
A
If
C
A
I)
C

A
I)
C

A
I)
('•
A
It
C

A
I)
C
Moisture
28.S30


26.670


27.290


27.010


26.720


27.140


25.490


23.960


23.740


26.320


29 190


30.720


26.6



30.904
43.241
45.635
29.897
40.770
42.480
30.073
41.361
44.189
30.241
41.432
44.439
28.930
39.478
42.998
28.786
39.509
43.283
30.717
41.225
43.895
32.554
42.811
44.998
32.853
43.080
45.408
29.855
40.519
44.361
29.104
41.102
43.782
29.460
42.523
44.608
29.6
40.3
43.4

36.817
51.514
54.365
40.482
55.205
57.520
37.983
52.239
55.811
37.810
51.801
55.561
38.353
52.337
57.002
37.721
51.772
56.717
39.261
52.693
56.105
39.792
52.330
55.002
39.498
51.794
54.592
37.444
50.820
55.639
37.372
52.778
56.21H
36.582
52.804
55.392
38.6
52.6
56.6
3.748
5.245

2.952
4.025

4.654
6.401

4.939
6.767

5.998
8.185

6.353
8.719
4.532
6.082

3.695
4.859

3.909
5.126
6.381
8.661
4.334
6.120

3.237
4.673
                                                                                  5.2
                                                                                  7.1
.149
.208
.220
.129
.175
.183
.166
.228
.244
.152
.208
.223
.175
.239
.260
.388
.533
.584

.142
.191
.203
.168
.221
.233
.149
.195
.206

.154
.209
.229

.120
.169
.180
.126
.182
.191

.200
.30Q
.300
.016
.022
.023
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.000
.016
.022
.024

.025
.034
.036
.025
.033
.035
.000
.000
.000

.000
.000
.000

.000
.000
.000
.000
.000
.000
.047
.066
.069
.016
.022
.023
.047
.065
.070
.040
.055
.059
.024;
.033
.036
.024
.033
.037

.000
.000
.000
.000
.000
.000
.017
.022
.023

.024
.033
.036

.000
.000
.000
.024
.034
.036
.086
.121
.127
.113
.154
.160
.119
.163
.174
.112
.153
.164
.151
.207
.225
.348
.478
.523

.117
.157
.168
.143
.188
.198
.132
.173
.183

.130
.176
.193

.120
.169
.180
.103
.148
.155
8699
12171
1284S
8812
12017
12521
8823
12134
12964
8694
11912
12776
8543
11659
12698
8496
11661
12774

8962
12028
12807
9314
12249
12875
9301
12197
12856

8558
11615
12717
8454
11939
12717
8373
12086
12678
8740
11910
12810










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Drill hole
and location
SH-7044
5S 46E S30
DDAD
SH-7045
5S 46E S20
CBBD



SH-7049
5S 46E S2
DCDB
SH-7051
4S 46E S33
CBBA
SH-7052
5S 45E S27
BDAC

SH-7053
4S 45E S4
AAAA



SH-7054
4S 45E S2
DBDC
SH-7055
4S 45E S6
DDBA
SH-7060
4S 46E S6
DDAC
Depth
sampled

178 to
199 ft.

60 to
65 ft.
106 to
127 ft.


177 to
197 ft.

116 to
1 35 ft.

106 to
126 ft.


112 to
156 ft.
156 to
171 ft.


84 to
1 06 ft.

216 to
218 ft.

141 to
153 ft.
Lab.
sample


233-235


238

229-231



246-248


250-251


253-254



255-259

260-261



262-264


265


271-272
Table 38.-Major ash constituents, Otter Creek coal deposit. o
foal Constituent, %
bed A12O3 CaO FejOs K2O MgO Na2O P2O5 SiO2 SO3 TiO2 Total
Knobloch 16.2 20.5 5.3 .5 3.5 7.5 .7 27.9 7.8 .6 90.5


Knobloch 4.9 5.4 61.5 .5 .8 2.7 .1 11.0 10.3 .1 97.3


12.4 20.4 4.9 .3 7.7 5.3 .5 32.2 10.5 .7 94.9
CO
H
Knobloch 16.4 23.8 5.0 .3 3.7 9.5 .2 28.6 8.3 .6 96.4 jg
13
n
Knobloch 18.1 24.1 5.0 .3 3.7 9.4 .7 30.3 7.2 .7 99.5 w
o

Knobloch 18.1 20.1 4.7 .2 3.1 8.9 1.2 29.0 10.8 .6 96.7 u>
O
^
X
Knobloch 20.4 20.6 3.6 .2 3.9 9.4 .4 31.0 6.3 .8 96.6 5
W
3
18.1 12.9 3.2 1.0 2.6 5.9 .2 42.2 9.5 .7 96.3 *
S
O
Knobloch 21.5 24.5 3.4 .2 5.3 5.3 .2 25.7 7.1 .6 93.9 H
fc
2
Knobloch 22.0 15.0 2.7 .2 2.5 6.9 .7 39.8 4.9 .8 95.5


Knobloch 19.6 22.5 3.8 .2 1.9 11.0 .1 30.2 5.9 .7 95.9



-------
                                         INDIVIDUAL DEPOSITS—ASHLAND
                                                                                                            71
                 Table 39.—Reserves, overburden, overburden ratio, acres, and tons/acre, Ashland coal deposit.
                                               KNOBLOCH BED
  Thickness of
 overburden, ft.
    Indicated reserves,
      million tons
 Overburden,
million cu. yd.
Overburden ratio,
 cubic yards/ton
Acres
Tons/acre
     Oto  SO
    SO to 100
   100 to 150
   ISO to 200
   200 to 250
         89.34
        414.26
        758.39
        866.39
        567.82
Total   2,696.20
                                   Total
     51.99              0.58               928
    535.63              1.29             4,416
   1,617.23              2.13             8,256
   2,579.97              2.98             7,616
   2.159.68              3.80             6.016
   6,944.50      Average  2.58     Total   27,200
                                 Average
                  96,271.6
                  93,808.9
                  91,859.3
                 113,759.2
                  94.384.9
                  99,125.0
                                            A, C, and SAWYER BEDS
     Oto  50
    50 to 100
   100 to 150
              Total
        146.04                 440.56
        111.99                 772.84
         99.46               1.128.97
        357.49        Total  2,342.37
             ASHLAND COAL DEPOSIT

                     LOCATION

   The Ashland coal deposit is in T. 2 and 3 S., R. 44,45,
and 46 E., Powder River and Rosebud Counties (PI. ISA,
B). The area is bounded on the west by the Tongue River,
which is also the east boundary of the Northern Cheyenne
Indian Reservation. It is bounded on the east by exces-
sively thick overburden on the divide between Pumpkin
Creek and Otter Creek. To the north, the area borders
the Beaver Creek-Liscom  Creek coal deposit (PI. 9), and
to the south, it borders the Poker Jim Creek-O'Dell Creek
coal deposit (PI. 1 IB), which is south of the southeastern
corner of T. 3 S., R. 44 E., and the Otter Creek coal de-
posit (PI. 12), which is south of T. 3 S., R. 45 and 46 E.

         FIELD WORK AND MAP PREPARATION
   The  field  work,  conducted during  the summer of
1970, included drilling and  surface mapping of the  coal
outcrops and clinker boundaries. Black-and-white aerial
photos were used for field mapping; colored aerial photos
borrowed from the Ashland Division of the U S. Forest
Service were used for further evaluation. Structure con-
tour maps of the top of the Knobloch and Sawyer  coal
beds were  prepared  and  7&-minute topographic maps
were used in the preparation of overburden maps.

             PREVIOUS GEOLOGIC WORK

   The outcrops of the major coal  beds as well as the
burned  areas  within the  Ashland area were originally
                       3.01
                       6.90
                      11.35
               Average  6.55
                      8,275.2
                      6,387.2
                      5.600.0
              Total   20,262.4
                  17,647.9
                  17,533.5
                  17.760.7
          Average  17,643.0
                                           mapped by Bass (1932). Two small strippable coal de-
                                           posits within the Ashland coal deposit were mapped by
                                           Brown and others (1954, p.  196) and described as the
                                           Home Creek and Cook Creek deposits. These two strip-
                                           pable  areas were also  included in a report on the strip-
                                           pable  coal resources of Montana by Ayler, Smith, and
                                           Deutman (1969).

                                                            LAND OWNERSHIP

                                             Most of the surface over the Ashland coal deposit  is
                                           privately owned. The deposit lies within the land grant to
                                           Burlington Northern, Inc., and although it has conveyed
                                           the  surface, the railroad has retained most minerals in-
                                           cluding coal in the odd-numbered sections outside the
                                           Custer National Forest. The State of Montana owns both
                                           surface and coal in sec. 16 and 36 of each township. Some
                                           coal along the tributaries of Otter Creek, including the
                                           East Fork of Otter Creek and Home Creek, is privately
                                           owned. The federal land outside the forest is administered
                                           by the U.S. Bureau of Land Management and that within
                                           the Custer National Forest by the US. Forest Service.

                                                    SURFACE FEATURES AND LAND USE

                                             The most prominent  surface feature in the Ashland
                                           area is the great mass of clinker formed by the burning
                                           of the Knobloch coal bed. In many places, the clinker is
                                           more than 100 feet thick. Along Otter Creek and its tribu-
                                           taries, the clinker forms high steep-sided banks and cliffs
                                           of reddish or multicolored altered rock, which supports
                                           the growth of ponderosa pine. The multicolored clinker,

-------
                                                 Table 40.-Proximate analysis, form* of sulfur, and heating value, Ashland coal deposit.
   Drill hole
  and location
  SH-7061
  3SR45ES14
  CBAB
 SH-7062
 3S R4SE S26
 DBAC
SH-7067
3SR45ES12
AABD
Depth
sampled
72 to
80ft.
Ill to
117ft.
117 to
121 ft.
60 to
68ft.
68 to
76ft.
76 to
85 ft.
85 to
94ft.
94 to
103 ft.
103to
112ft
112 to
1 16 ft.
101 to
lllft.
Hlto
119ft.
119 to
127 ft.
127 to
136ft.
136 to
144 ft.
144 to
153 ft.
153 to
154 ft.
Lab.
number
273
274
275
276
277
278
279
280
281
282
287
288
289
290
291
292
293
  Coal
  bed
                                            Knobloch
 Knobloch
Knobloch
Form of
analysis
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
Proximate. %
i
/ Moisture
30.050


28.400


29.280


27.630


26.560


26.020


27.040

25.700


27.250


28.220


29.470


28.200


28.120


28.860


28.620


28.520


29.440


Volatile
matter
28.655
40.966
43.488
28.777
40.191
42.691
26.512
37.489
40.883
30.525
42.179
45.105
31.255
42.559
45.158
29.107
39.345
42.502
29.232
40.065
42.189
30.066
40.465
43.929
30.513
41.942
44.436
29.488
41.081
43.646
28.253
40.058
42.511
29.082
40.504
43.217
29.660
41.263
44.082
27.862
39.165
43.309
27.997
39.223
42.670
28.362
39.679
42.378
26.880
38.096
41.815
Fixed
carbon
37.237
53.234
56.512
38.631
53.954
57.309
38.336
54.208
59.117
37.150
51.333
54.895
37.957
51.685
54.842
39.376
53.226
57.498
40.055
54.900
57.811
38.376
51.650
56.071
38.154
52.445
55.564
38.073
53.041
56.354
38.208
54.173
57.489
38.211
53.219
56.783
37.624
52.343
55.918
36.471
51.267
56.691
37.616
52.698
57.330
38.565
53.952
57.622
37.404
53.010
58.185

Ash
4.057
5.801

4.192
5.855

5.872
8.303

4.695
6.488

4.228
5.757

5.497
7.430

3.673
5.035
5.858
7.884

4.083
5.613

4.220
5.879

4.069
5.769

4.507
6.278

4.596
6.394

6.807
9.568

5.767
8.079

4.553
6.369

6.275
8.894

                                                                                                                       Form oL sulfur. %
Sulfur
.142
.204
.216
.169
.236
.251
.191
.270
.294
.133
.183
.196
.117
.160
.170
.160
.216
.234
.131
.180
.189
.159
.214
.232
.115
.158
.168
.239
.333
.354
.119
.168
.178
.106
.148
.158
.119
.165
.177
.132
.185
.205
.109
.153
.167
.163
.228
.243
.450
.638
.701
Sulfate
.000
.000
.000
.000
.000
.000
.000
.000
.000
.017
.023
.024
.017
.023
.024
.000
.000
.000
.016
.022
.024
.026
.036
.039
.016
.023
.024
.017
.024
.025
.008
.011
.012
.016
.023
.024
.016
.022
.024
.008
.012
.013
.016
.022
.024
.009
.012
.013
.008
.011
.012
Pyritic
.016
.023
.024
.017
.024
.025
.024
.034
.037
.017
.023
.024
.017
.023
.024
.008
.011
.012
.016
.022
.024
.044
.059
.064
.016
.023
.024
.017
.024
.025
.016
.022
.024
.016
.023
.024
.016
.022
.024
.025
.035
.038
.016
.022
.024
.017
.024
.026
.070
.099
.109
Organic
.127
.181
.192
.152
.212
.226
.167
.236
.258
.099
.137
.147
.084
.114
.121
.152
.205
.221
.098
.135
.142
.088
.119
.129
.082
.113
.120
.205
.286
.303
.095
.134
.143
.074
.103
.109
.087
.121
.130
.099
.139
.154
.078
.109
.119
.137
.192

'373
.'528
.580
Heating
value (Bui)
8275
11829
12558
8576
11978
12723
8226
11631
12685
8431
11650
12458
8759
11927
12655
8591
11612
12544
8704
11930
12562
8758
11787
12796
8642
11879
12586
8643
12041
12793
8395
11903
12632
8536
11888
12684
8495
11818
12625
8242
11586
12812
8337
11680
12707
9070
12689
13552
8216
11643
12780










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-------
SH-7068
3SR45ES10
BDDC
SH-7071
3S R45E S8
ABBC
SH-7064
3S R46E S8
CACC
SH-7066
2S R45E S36
CDCD

SH-7070
2S R4SE S21
CBDA
115 to
125 ft.

125 to
134ft.

134 to
142 ft.

142 to
152 ft.

152 to
160ft.

160 to
164 ft.
139 to
147 ft.

147 to
157 ft.

157 to
165 ft.

165 to
169 ft.
 90 to
 97ft.

 97 to
100 ft.
 82 to
 92ft.
152 to
162 ft
                       Knobloch
295


296


297


298


299


300



302


303


304


305






283


284



286



301
                       Knobloch
Sawyer






Sawyer



Sawyer
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
30.180


31.070


32.350


30.980


32.070


32.030


26.730


27.640


28.730


26.160


28.698
41.103
43.841
27.610
40.055
42.857
27.269
40.308
43.081
27.152
39.339
42.711
26.572
39.117
42.167
27.882
41.021
44.361
30.459
41.570
44.131
29.963
41.409
44.346
29.884
41.931
44.595
30.526
41.340
44.604
36.762
52.652
56.159
36.813
53.407
57.143
36.028
53.257
56.919
36.419
52.766
57.289
36.445
53.651
57.833
34.970
51.449
55.639
38.559
52.626
55.869
37.604
51.968
55.654
37.128
52.095
55.405
37.911
51.342
55.396
A
B
C
A
B
C

A
B
C

A
B
C
31.490


31.540



31.610



32.910
28.978
42.297
44.938
33.051
48.278
52.927

28.117
41.112
44.127

30.161
44.957
48.510
35.506
51.827
55.062
29.396
42.939
47.073

35.601
52.056
55.873

32.014
47.718
51.490
4.360
6.245

4.507
6.538

4.353
6.435
5.449
7.895

4.913
7.232

5.118
7.530

4.252
5.803

4.793
6.623

4.258
5.974

5.403
7.317

4.026
5.876

6.013
8.783

4.672
6.832

4.914
7.325

.130
.186
.198
.114
.165
.176
.136
.201
.215
.143
.207
.224
.158
.233
.251
.232
.342
.370
.113
.154
.164
.104
.144
.154
.113
.158
.168
.146
.198
.214
.352
.514
.546
.916
1.338
1.467
.297
.435
.467
.400
.597
.644
.000
.000
.000
.015
.022
.024
.023
.034
.036
.008
.011
.012
.008
.012
.013
.008
.012
.013
.008
.011
.012
.008
.011
.012
.008
.011
.012
.008
.011
.012
.015
.022
.024
.017
.025
.027
.015
.022
.024
.008
.012
.013
                                                                                      .024
                                                                                      .035
                                                                                      .037
                                                                                      .015
                                                                                      .022
                                                                                      .024
                                                                                      .060
                                                                                      .089
                                                                                      .096
                                                                                      .040
                                                                                      .057
                                                                                      .062
                                                                                      .024
                                                                                      .035
                                                                                      .038
                                                                                      .008
                                                                                      .012
                                                                                      .013

                                                                                      .024
                                                                                      .033
                                                                                      .035
                                                                                      .016
                                                                                      .022
                                                                                      .024
                                                                                      .040
                                                                                      .056
                                                                                      .060
                                                                                      .008
                                                                                      .011
                                                                                      .012
.015
.022
.024
.221
.322
.353

.008
.011
.012

.086
.129
.139
                                                                                    .105
                                                                                    .151
                                                                                    .161
                                                                                    .083
                                                                                    .121
                                                                                    .129
                                                                                    .053
                                                                                    .078
                                                                                    .084
                                                                                    .095
                                                                                    .138
                                                                                    .150
                                                                                    .127
                                                                                    .186
                                                                                    .201
                                                                                    .216
                                                                                    .318
                                                                                    .344

                                                                                    .081
                                                                                    .110
                                                                                    .117
                                                                                    .080
                                                                                    .111
                                                                                    .118
                                                                                    .064
                                                                                    .090
                                                                                    .096
                                                                                    .130
                                                                                    .176
                                                                                    .190
 .321
 .469
 .499
 .678
 .991
1.087

 .274
 .401
 .431

 .306
 .456
 .492
8196
11739
12521
8047
11674
12490
7981
11798
12609
8004
11596
12590
7671
11293
12173
7893
11612
12558
8800
12010
12750
8645
11947
12795
8564
12017
12780
8655
11721
12646


7965
11627
12353
7740
11306
12394
8015
11720
12579
7814
11646
12567














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 /A, as received; B, moisture free; C, moisture and ash free.

-------
                       Table 41.-Major ash constituents, Ashland coal deposit.
Coal
Constituent, %
and location
SH-7061
3S 45E S14
CBAB


SH-7062
3S 45E S26
DBAC

SH-7067
3S45ES12
AABD

SH-7068
3S 45E S10
BDDC
SH-7071
3S 45E S8
ABBC


SH-7064
3S46ES8
CACC
SH-7066
2S 45E S36
CDCD
SH-7070
2S4SES21
CBDA
sampled sample bed AljO3 CaO FejOj K3O MgO NaaO P2OS SiOj SO3 TiOj Total
Knobloch 21.2 27.1 4.3 .2 3.8 8.4 .6 26.9 6.1 .6 99.2
72 to
80 ft. 273
lllto 17.6 21.5 3.8 2 3.1 6.2 .1 37.9 6.5 .7 97.6
121 ft. 274-275
Knobloch 18.1 23.8 3.4 .1 6.1 3.2 .1 34.1 7.9 .7 97.5
60 to
116ft. 276-282

Knobloch 17.2 20.1 4.1 .4 3.1 7.6 .3 36.4 8.0 .7 97.9
101 to
154 ft. 287-293

Knobloch 18.7 19.0 4.1 .2 2.8 8.2 _S 33.3 8.0 .7 95 J
115 to
164 ft. 295-300
Knobloch 20.3 23.8 4.3 .3 3.8 6.3 .3 31.9 5.4 .8 97.2
139 to
169 ft. 302-305


Sawyer 12.4 19.7 7.3 .3 4.2 10.2 23 20.5 20.0 J 97.4
90 to
100 ft. 283-284
Sawyer 18.0 18.8 5.5 .6 3.1 11.8 1.4 25.9 11.8 J 97.4
82 to
92 ft. 286
Sawyer 16.6 18.5 7.1 .4 315 10.5 1.7 22.1 14.9 J 95.8
152 to
162 ft. 301






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-------
                                       INDIVIDUAL DEPOSITS—ASHLAND
                                                                                                          75
the large terrace levels above the river valleys, which sup-
port thin stands of ponderosa pine, and the barren buttes
in the background present picturesque scenery.

   The surface in the Ashland coal field is deeply dissect-
ed along the valleys of Otter  Creek, the East Fork  of
Otter Creek, and Home Creek. Beyond and above the
clinkered areas, the surface  is  rolling and supports the
growth of native grasses. The divide between Otter Creek
and Pumpkin Creek  to the  east is sharp and is covered
with ponderosa pine.

   The flood plain of Otter Creek is about % of a mile
wide in the Ashland area. Flood plains  of Home Creek
and East Fork of Otter Creek are about % of a mile wide.
In T. 2 S., R. 44 and 45 E., the tributaries of the Tongue
River are relatively short and steep and head in the Cook
Mountains; these  mountains form  a  high divide, which
separates the East Fork of Otter Creek from Beaver Creek
to the north.

   The principal land use within the Ashland coal  field is
livestock grazing. Hay is raised as a principal crop in the
meadows along the valley bottoms of Otter Creek, its
tributaries, and Tongue River. Some grain is cultivated on
the rolling terrain above the rugged topography developed
on the clinker. Lumbering is limited to the ponderosa
pine stands growing  on  the  higher ground  surrounding
Ashland.

               GEOLOGIC STRUCTURE

   The strata in the  Ashland coal  field  are nearly flat.
Along the East  Fork of Otter Creek, the dip is about 20
feet per mile to the southwest. In T. 2 S., R- 44 and 45 E..
the dip is about 40 feet per mile to the south as shown by
drill hole data of the Sawyer coal bed. Some reversals do
occur, and one of these, near the center of T. 2 S., R. 45 E.,
coincides with the topographic high of the Cook Moun-
tains.

                     COAL BEDS

   The  Knobloch and Sawyer coal beds both contain
strippable reserves in the Ashland coal deposit. The Knob-
loch, ranging in thickness from 40 to 58 feet, is the more
important. To the north, in T. 2 S., R. 44 and 45 E., it is 40
to 50 feet thick, but farther south, in T. 3 S., R. 45 and
46 E., it is 50 to 58 feet thick.

   The Sawyer coal bed, about  11>5  feet above the Knob-
loch bed, is about  10 feet thick as measured in drill holes
SH-7064, sec. 8, T. 3 S., R. 46  E.. and SH-7070, sec. 21,
T. 2 S., R.  45  E. In this latter drill hole,  an upper bench
 6 feet thick may be  the C or D bed described by Bass
 (1932, p. 55). A surface mine in sec. 3, T. 3 S., R. 45 E., is
 producing from the Sawyer coal bed. Near the mine, in
 drill hole SH-7066, sec. 36, T. 2 S., R. 45 E., the Sawyer
 coal bed has a measured thickness of 14 feet.

   Other beds that are minable in the northeastern part
 of the area (PI. 13B) are the C and D coal beds, which
 have a combined thickness as great as 11 feet, and the A
 bed, which has a thickness of 9 feet. Sections of the Saw-
 yer bed, the A bed about 80 feet below it, and the D bed
 about 220 feet above it, were measured by Bass (1932).

   Two other beds in the  area may correlate with the
 Flowers-Goodale and Terret beds described by Bass (1932,
 p. 53). Both are below the Knobloch bed; the upper bed
 has a thickness of 8 feet in drill hole SH-7067 in sec. 12,
 T. 3 S., R. 45  E.  The gamma log of an oil well in the
 NE& sec. 28, T. 3 S., R. 45 E., shows a coal bed at an alti-
 tude of 2,973 feet, which is very near the same as the bed
 below  the  Knobloch in drill hole SH-7067. The gamma
 log shows a 3-foot bench separated by an 8-foot parting
 from a 6-foot bench. A lower bed, at an altitude of 2,844
 feet, has a thickness of 6 feet.

                  COAL QUALITY

   Only one earlier report of analysis of coal from this
 area is available; that sample was obtained from the Coal
 Creek mine in sec. 3, T. 3 S., R. 45 E. In this analysis, the
 moisture content is 30%, volatile  matter is 29.3%, fixed
 carbon is 35.8%, ash  content is 4.9%, sulfur content is
 0.5%, hydrogen content is 6.5%, carbon content is 48.6%,
 nitrogen content is 0.7%, oxygen  content is 38.8%, and
 the heating value is 8,160 Btu.

   Thirty-one core samples obtained from  the Ashland
 coal field on this project were analyzed by the Montana
 Bureau of Mines and Geology analytical laboratory. Prox-
 imate analysis,  forms of sulfur,  and  heating value  are
 shown in Table 40,  and major ash constituents are shown
 in Table 41.

                  COAL RESERVES

   The Knobloch coal bed contains large strippable re-
 serves. The areas of greatest potential are along the East
 Fork of Otter Creek and along Home Creek, where the
 Knobloch bed is thickest and the terrain is most favorable
 to strip mining.

   Strippable reserves in  the Knobloch coal bed total
 2,696,200,000 tons and in the A, C, and Sawyer coal
beds 357,490,000 tons (Table 19).

-------
76
                 STRIPPABLE COAL, SOUTHEASTERN MONTANA
                   Table 42.—Reserves, overburden, overburden ratio, acres, and tons/acre, Colstrip coal deposit.
                                                 ROSEBUD BED
    Thickness of
    overburden, ft.
   Indicated reserves,
      million tons
     Overburden,
    million cu. yd.
  Overburden ratio,
   cubic yards/ton
Acres
       Tons/acre
       Oto  50
      50 to 100
     100 to 150
        523.86
        457.43
        457.97
Total   1,439.26
        646.4
       1,281.06
       2.146.19
Total   4,073.65
        1.23
        2.8
        4,69
Average  2.83
                                                                        Total
12,143.7
10,589.3
10.646.1
33,379.1
        43,137.4
        43,198.5
        43.017.8
Average  43,118.6
             COLSTRIP COAL DEPOSIT

                     LOCATION

   The Colstrip coal deposit (PI. 14) is in T. 1  and 2 N.,
 R. 38, 39,40,41, and 42 E., and T. 1 S., R. 40 and 41 E.,
 Rosebud and Treasure Counties. The community of Col-
 strip, in sec. 34, T. 2 N., R. 41 E., had a population of 304
 in 1960. As a result of expanded mining operations and
 construction of two new 350-megawatt power plants just
 east of Colstrip, the  population has increased dramati-
 cally. The Montana Power Company purchased the com-
 munity of Colstrip, along with mining leases and mining
 equipment,  from Burlington  Northern,  Inc.,  in 1959.
 Western Energy Company, a subsidiary of The Montana
 Power Company, operates the Rosebud mine near Colstrip
 and ships the coal by unit train to The Montana Power
 Company 180-megawatt steam generation plant  at Billings
 and to markets  in the upper Midwest.

   Another strip mine a few miles south of Colstrip is the
 Big  Sky mine, opened in 1969 and operated by Peabody
 Coal Company. Coal from this mine is being shipped by
 unit train to northern Minnesota for use  in power gener-
 ation.

   Surface  mining in the Colstrip area began in 1924,
 when the Northwestern Improvement Company opened
 the  pit in the Rosebud coal bed near Colstrip  to supply
 coal for locomotives of the parent Northern Pacific (now
 Burlington Northern, Inc.). The mine operated until the
 mid 50's but closed when coal was no longer needed for
 steam locomotives. Western Energy Company reopened
 the Colstrip mine in 1968.

          FIELD WORK AND MAP PREPARATION

   The field work in the Colstrip area was conducted en-
 tirely by the staff of Burlington Northern, Inc., under
                                        the supervision of Virgil W. Carmichael in 1964, using
                                        the method developed by Burlington Northern (Carmi-
                                        chael, 1967). The field method involved establishing tem-
                                        porary benchmarks throughout the area  and obtaining
                                        vertical control through the use of closely controlled al-
                                        timeter surveys. Holes were drilled and cores were taken
                                        to obtain quantitative and qualitative information on the
                                        coal and to obtain structural information for preparation
                                        of overburden maps. A few of the 69  drill holes pene-
                                        trated the underlying McKay coal bed.

                                           The overburden map  for the Colstrip  area was com-
                                        pleted during the winter of 1964-65 by Burlington North-
                                        ern personnel.

                                                      PREVIOUS GEOLOGIC WORK

                                           Geology in the Colstrip area was mapped and described
                                        by Dobbin (1929) and by Kepferle (1954). Ayler, Smith,
                                        and Deutman (1969) included the area in their report on
                                        the strippable coal resources in Montana.

                                                          LAND OWNERSHIP

                                           The coal  field  lies within  the land  grant of odd-
                                        numbered sections to Burlington Northern, Inc., who ob-
                                        tained possession of additional land in T. 1 and 2 N., R. 39,
                                        41, and 42 E. Burlington Northern has  sold some of its
                                        surface and minerals to  The Montana Power Company
                                        but has retained title to much of the surface in the Col-
                                        strip area. The Federal Government owns  the coal in the
                                        even-numbered sections in the  Colstrip area except for
                                        sec. 16 and 36 in each township, which are owned by the
                                        State of Montana.

                                                  SURFACE FEATURES AND LAND USE

                                           The Colstrip coal deposit is on the divide between
                                        Rosebud Creek to the east and Armells Creek. Most of

-------
                                      INDIVIDUAL DEPOSITS—COLSTRIP
                                                 77
 the divide is gently rolling, but  near the northern and
 eastern edges of the mapped area, it is relatively stee-p
 and deeply dissected where the clinker  forms a resistant
 multicolored zone. Farther west, buttes and ridges ate
 capped by clinker from the burning of higher coal beds.
 Armells Creek is an intermittent stream of gentle gradien';,
 and flows only during periods of heavy precipitation and
 spring runoff. In the southern part of the mapped are j,
 the valleys are steep sided where the Sawyer coal bed,
 which lies above the  Rosebud bed, has burned and tr e
 clinker caps the ridges between the valleys of Coal Bank
 Creek, Miller Creek, and Cooley Creek.  To the west, the
 Little  Wolf Mountains form a  high  divide  between
 Armells Creek and Sarpy Creek.

   Ponderosa pine trees grow along  the valley  sides
 throughout the area.  Part of the valley of Armells Creek
 is utilized for dry-land farming. Hay is raised in meadow*
 along the valley bottoms.

               GEOLOGIC STRUCTURE

   The strata in the coal field are almost horizontal, ex-
 cept where disturbed  by a few faults, which have only
 small  displacement. Generally the top of the Rosebud
 coal bed is highest in T. 2 N., R. 39 E., and lowest in
 T. 1 N., R. 41 E.

                     COAL BEDS

   The principal coal  beds in the Colstrip area are the
 Rosebud and the McKay beds. Thickness of the Rosebud
bed is a maximum of 29 feet in drill hole RB-43, sec. 27,
T. 1 N., R. 41 E., and averages about 25  feet throughout
the area. In certain parts of the coal field, the Rosebud
contains a parting in the center or upper quarter of the
coal bed, and in some areas, this parting attains a thick-
ness of as much as 2 feet.
   The McKay coal bed is 18 feet below the Rosebud in
drill hole RB-48, sec. 13, T, 1 N., R. 41 E., and 61 feet in
drill hole RB-58, sec. 5, T. 1 N., R. 41 E. Thickness of the
McKay bed averages about 8 feet. Three thinner coal beds
in the Tongue  River Member below the Rosebud and
McKay coal beds have been mapped in the area (Dobbin,
1929). The Stocker Creek coal bed (0 to 12 feet thick) is
about 40 feet below the top of the McKay, the Robinson
coal bed (0 to 8 feet thick) is about  140 feet below the
top of the Stocker Creek bed, and the  Burley coal bed (0
to 5 feet thick) is about 60 feet below the Robinson coal
bed. A still lower coal bed, the Big Dirty, is about 250
feet below the  Burley oed, but it is in the Lebo Shale
Member of the Fort Union Formation. It crops out next
to the road about  10 miles north of  the community of
Colstrip. Several coal beds above the  Rosebud bed crop
out in the Little Wolf Mountains; these include the Lee,
Popham, Sawyer, Proctor, and Richard coal beds. The
clinker formed as a result of the burning of the  Sawyer
bed, which is about  300 feet above the Rosebud, caps
buttes and ridgetops throvghout the area.

                   COAL QUALITY

   Nineteen coal cores obtained on the Colstrip  drilling
project were analyzed by  US. Bureau  of Mines Grand
Forks Coal Research Laboratory. Proximate analysis, ul-
timate analysis, and heating value are shown in Table 43,
and forms of sulfur and ash fusibility are shown in Table
44.

   All core samples are of the Rosebud coal except three
samples of the McKay.


                  COAL RESERVES


   Reserves in the  Colstrip deposit total 1.439.260.000
tons (Table 42).

-------
                                             Table 43.-Proximate analysis, ultimate analysU, and heating value, CoUtrip coal deposit.
                                                                                                                                                       co
  Drill hole
 and location
 RB-46
 1N41ES15
 CDDD
 RB-54
 IN 40E S27
 AABA

 RB-S5
 IN 40E S23
  Depth      Lab.
 sampled     number
 RB-S6
 1N41ES30
 BDAD

 RB-57
 1N40ES11
 BABB

 RB-58
 IN 41E SS
CAAB
RB-S9
2N41ES31
ADAD
  54 to
  87ft.

 100 to
 108 ft.
 145 to
 170 ft.
 77 to
 101ft.
 80 to
 56% to
 77H ft.

138 to
146% ft.
 71 to
 81ft.
 H-97821


 H-97822



 H-97823



 H-97824
 27V4to
 53 ft.      H-97825
H-97826



H-97827


H-97828



H-97829
                Coal
                bed
 Rosebud


 McKay



 Rosebud



 Rosebud
                         Rosebud
Rosebud



Rosebud


McKay



McKay
            Form of
                   1,
 A
 B
 C
 A
 B
 C

 A
 B
 C

 A
 B
 C

 A
 B
 C

 A
 B
 C

 A
 B
 C
 A
 B
 C

 A
 B
C
Proximate, %

Moisture
21.51


21.76



23.40


21.48



22.58


23.14


23.07


24.45


22.23


Volatile
matter
29.71
37.86
42.56
27.88
35.63
39.55

28.63
37.38
41.65
29.46
37.53
44.69

28.80
il.M
41.91
29.58
38.48
43.27
28.43
36.96
41.49
27.89
36.91
40.39
28.78
37.00
41.12
Fixed
carbon
40.11
51.09
57.44
42.61
54.47
60.45

40.11
52.36
58.35
36.48
46.44
55.31

39.92
51.57
58.09
38.77
50.45
56.73
40.11
52.13
58.51
41.16
54.49
59.61
41.20
52.98
58.88

Ash
8.67
11.05

7.75
9.90


7.86
10.26

12.58
16.03


8.70
lt.23

8.51
11.07

8.39
10.91

6.50
8.60

7.79
10.02


S
0.77
0.99
1.11
1.87
2.39
2.65

0.68
0.89
0.99
0.75
0.95
1.13

0.97
1.26
1.42
.68
.89
1.00
0.99
1.28
1.44
1.41
1.86
2.04
1.23
1.58
1.75

H
5.97
4.55
5.12
5.76
4.27
4.74

6.11
4.58
5.11
5.66
4.17
4.96

6.04
4.56
5.13
6.08
4.57
5.14
6.02
4.49
5.04
6.10
4.48
4.90
5.88
4.39
4.88
Ultimate,

C
53.12
67.67
76.08
53.07
67.83
75.29

52.62
68.69
76.55
49.42
62.95
74.96

52.45
67.75
76.32
51.85
67.46
75.86
52.36
68.06
76.40
52.50
69.48
76.03
52.83
67.93
75.49
%

N
0.79
1.01
1.13
0.79
1.01
1.12

0.80
1.04
1.16
.72
.92
1.09

.81
1.04
1.17
.82
1.06
1.19
0.80
1.04
1.17
0.81
1.08
1.18
.92
1.19
1.32



Heating


O value (Btu)
30.68
14.73
16.56
30.76
14.60
16.20

31.93
14.54
16.19
30.87
14.98
17.86

31.03
14.16
15.96
32.06
14.95
16.81
31.44
14.22
15.95
32.68
14.50
15.85
31.35
14.89
16.56
9090
11580
13010
9060
11580
12850

9050
11810
13160
8400
10700
12740

9060
11710
13190
8950
11650
13100
8920
11590
13010
8930
11820
12930
8980
11550
12830






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-------
RB-60
2N41ES31
BCDC

RB-61
1N40ES3
BCCC

RB-63
2N 40E S32
ABCD
RB-64
2N 39E S34
ABCD

RB-65
2N 39E S29
CCCC

RB-66
2N38ES13
CAAB

RB-67
IN 40E S9
CCBC

RB-68
IN 40E S4
DADA

RB-69
1N40ES5
CBBC
 73 to
 99% ft.     H-97830
 72 to
 97% ft.    H-97831
 80 to
100% ft.

100% to
108 ft.
 52 to
 78ft.
 86 to
112% ft.
 89 to
115 ft.
 73 to
100ft.
H-97832
                           H-97833
 35% to
 60 ft.      H-97834
115 to
142% ft.    H-97835
H-97836
H-97837
H-97838
H-97839
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
A
B
C

A
B
C

A
B
C
A
B
C

A
B
C

A
B
C

A
B
C

A
B
C

A
B
C

A
B
C
22.20


21.98


23.76


21.31




22.59



22.96



20.24


22.67


23.88


23.23


29.99
38.55
43.52
29.68
38.04
42.87
28.16
36.94
41.91
27.53
34.99
44.21


29.38
37.96
42.62

29.68
38.52
43.18

30.21
37.87
44.04
28.71
37.12
42.25
28.99
38.09
42.63
28.77
37.48
42.67
38.92
50.02
56.48
39.53
50.67
57.13
39.03
51.20
58.09
34.74
44.15
55.79


39.56
51.10
57.38

39.06
50.70
56.82

38.38
48.12
55.96
39.24
50.76
57.75
39.01
51.25
57.37
38.66
50.35
57.33
8.89
11.43

8.81
11.29

9.05
11.86

16.42
20.86



8.47
10.94


8.30
10.78


11.17
14.01

9.38
12.12

8.12
10.66

9.34
12.17

1.00
1.29
1.45
1.07
1.37
1.54
0.53
0.70
0.79
7.20
9.15
11.56


0.82
1.06
1.19

0.81
1.05
1.18

0.68
0.85
0.99
0.91
1.18
1.34
0.74
0.97
1.09
0.95
1.24
1.41
6.01
4.56
5.15
5.93
4.48
5.05
6.03
4.45
5.05
5.41
3.87
4.89


6.04
4.56
5.12

6.11
4.62
5.18

5.76
4.40
5.11
5.97
4.48
5.10
6.17
4.63
5.18
6.04
4.50
5.13
52.25
67.15
75.82
52.48
67.26
75.82
50.82
66.65
75.62
43.63
55.45
70.06


52.70
68.08
76.45

52.47
68.11
76.34

51.81
64.95
75.53
51.10
66.09
75.20
51.75
67.99
76.10
51.54
67.13
76.43
0.81
1.04
1.18
0.78
1.00
1.13
0.79
1.03
1.17
0.71
0.91
1.15


0.79
1.03
1.15

0.78
1.02
1.14

0.79
0.99
1.15
0.82
1.06
1.21
0.79
1.04
1.16
0.77
1.00
1.14
31.04
14.53
16.40
30.93
14.60
16.46
32.78
15.31
17.37
26.63
9.76
12.34


31.18
14.33
16.09

31.53
14.42
16.16

29.79
14.80
17.22
31.82
15.07
17.15
32.43
14.71
16.47
31.36
13.96
15.89
8990
11550
13050
9020
11560
13030
8680
11380
12920
7810
9930
12550


8990
11610
13030

9010
11700
13110

8820
11050
12850
8840
11430
13000
8940
11740
13140
8800
11470
13060









z
o
^
D
G

r
M
§
o
Cfi
N*
09
^
o
E
H
•0









 /A, as received; B, moisture free; C, moisture and ash free.

-------
                                                      Table 44.-Formi of sulfur and fusibility of ash, Colstrip coal deposit.
  Drillhole
 and location
  Depth      Lab.
 sampled     number
                 Coal      Form of
                 bed      analysis  /  Sulfur
                                                                             Form of sulfur. %
Sulfate
Pyritic
                                                                                                      Fusibility of ash. F
Organic
  Initial                           Real
deformation   Softening   Fluid    specific
   temp.        temp.    temp.    gravity
 RB46
 1N41ESI5
 CDDD
 RB-54
 IN 40E S27
 AABA

 RB-55
 IN 40E S23
 BDDB

 RB-S6
 IN 41E S30
 BDAD

 RB-57
 1N40ES11
BABB

RB-58
 IN 41E SS
CAAB
RB-5<>
2N 41E S31
ADAD
  54 to
  87 ft.

100 to
108 ft.
 56% to.
 77% ft.

138 to
146% ft.
H-97821
                            H-97822
145 to
170 ft.     H-97823
 77 to
101 ft.     H-97824
 27% to
 53 ft.     H-97825
 80 to
107% ft.    H-97826
H-97827
                            H-97828
                          Rosebud
                                          McKay
                         Rosebud
                         Rosebud
                         Rosebud
                         Rosebud
                         Rosebud
                                          McKay
                         McKay
 71 to
 81 ft.     H-97829
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
0.77
0.99
1.11
1.87
2.39
2.65
0.68
0.89
0.99
0.75
0.95
1.13
0.97
1.23
1.42
.68
.89
1.00
0.99
1.28
1.44
1.41
1.86
2.04
1.23
1.58
1.75
0.03
0.03
0.04
0.05
0.07
0.07












0.02
0.02
0.03
0.04
0.05
0.06



0.35
0.45
0.50
1.54
1.97
2.19












0.58
0.75
0.84
1.09
1.45
1.58



0.40
0.51
0.57
0.27
0.35
0.39












0.39
0.50
0.56
0.27
0.36
0.40



                                                                                    2340
                                                                                    2080
                                                                                    2160
                                                                                    2160
                                                 2380      2420
                                                 2120      2150
                                                 2200      2240
                                                 2200      2230
                                                         1.50


                                                         1.53
                                                                                    2370
                                                                                    2100
                                                 2420      2470
                                                 2150      2210
                                                                                                                                        o
                                                                                                                                        o
                                                                                                                             CO
                                                                                                                             o
                                                                                                                             1
                                                                                                                             *
                                                                                                                             a
                                                                                                                             i
                                                         1.51
                                                                                                                    1.51
                                                                                    2100
                                                 2150     2200

-------
RB-60
2N41ES31
BCDC

RB-61
IN 40E S3
BCCC

RB-63
2N 40E S32
ABCD
RB-64
2N 39E S34
ABCD

RB-65
2N 39E S29
CCCC

RB-66
2N 38E S13
CAAB

RB-67
IN 40ES9
CCBC

RB-68
1N 40E S4
DADA

RB-69
IN 40E S5
CBBC
 73 to
 99% ft.    H-97830
 72 to
 97% ft.    H-97831
 80 to
100% ft.    H-97832

100% ft.
108 ft.     H-97833
 35% to
 60 ft.     H-97834
115 to
142% ft.
 52 to
 78ft.
 89 to
115 ft.
 73 to
100 ft.
H-97835
H-97836
 86 to
112% ft.    H-97837
H-97838
H-97839
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
                        Rosebud
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
1.00
1.29
1.45
1.07
1.37
1.54
0.53
0.70
0.79
7.20
9.15
11.56
0.82
1.06
1.19
0.81
1.05
1.18
0.68
0.85
0.99
0.91
1.18
1.34
0.74
0.97
1.09
0.95
1.24
1.41






0.03 0.13 0.37
0.04 0.17 0.49
0.04 0.20 0.56
0.29 5.86 1.04
0.37 7.45 1.33
0.47 9.42 1.68


















                                                                                 2100         2150     2200
                                                                                 2050         2110     2160

2240

2020

2280

2060

2320

2100

1.51

1.70
2
O
O
C
>
                                                                                 2140
                                                                                 2150
                                                                                  2420
                                                                                  2240
                                                                                  2180
                                                                                  2130
2180
2200
2470
2220
2300
2520
                                                                                                                                                    o
                                                                                                                                                    U)
A
o
r
CD
H
2280      2320
2230      2300
2170      2210
 /A, as received; B, moisture free; C, moisture and ash free.
                                                                                                                                                    oo

-------
82
                                 STRIPPABLE COAL, SOUTHEASTERN MONTANA

               Table 45.-Reserves, overburden, overburden ratio, acres, and tons/acre, Pumpkin Greek coal deposit.
                                                 SAWYER BED
   Thickness of
   overburden, ft.
Indicated reserves,
  million tons
     Overburden,
    million cu. yd.
               Overburden ratio,
                cubic yards/ton
                         Acres
Tons/acre
       Oto 50
      50 to 100
     100 to 150
     150 to 200
     200 to 250
               Total
     560.0
     760.8
     647.2
     428.8
      29.7
   2,426.5
Total
 781.6
1,820.2
2^80.2
2^14.8
 191.9
7,888.7
                           1.39
                           2.39
                           3.98
                           5.86
                           6.46
                        10,726.4
                        14,323.2
                        11,685.4
                         8,416.0
                           544.0
Average  3.25     Total    45,695.0    Average
 52,209.6
 53,117.4
 55,387.2
 50,950.6
 54.595.6
 53,102.1
          PUMPKIN CREEK COAL DEPOSIT

                      LOCATION

   The Pumpkin Creek coal deposit (PI. 15) is in T. 2, 3,
 and 4 S., R. 48 and 49 E., Powder River County. U.S.
 Highway  212 traverses the northern  part of T. 4  S.,
 R. 49 E., and the southern part of T. 3 S., R. 48 E. The
 Pumpkin Creek coal deposit adjoins the Sonnette coal  de-
 posit (PI. 25) to the south, the Broadus coal deposit (PI.
 18) to the east, the Little Pumpkin Creek coal deposit
 (PI. 27) to the northwest, the Threemile Buttes coal  de-
 posit (PI. 24) to the  southwest, and the Foster Creek coal
 deposit (PI. 16) to the north.

          FIELD WORK AND MAP PREPARATION

    All of the field work resulting  in the present map of
 Pumpkin  Creek coal deposit was done  by the  Mineral
 Development Division of Burlington Northern, Inc., dur-
 ing the summer of 1965. Evaluation of the data was com-
 pleted late in 1966. The  field method utilized was  de-
 veloped by Burlington Northern, Inc. (Carmichael, 1967)
 for areas where adequate topographic  maps were  not
 available. Temporary benchmarks for topographic control
 were established by leveling and then served as base  sta-
 tions  for altimeter surveys. Altimeter elevations along
 with coal outcrops,  clinker, and contacts between burned
 areas and unburned areas were plotted on aerial photos,
 as were the holes that were drilled to measure coal thick-
 ness and  depth. Cores were taken for analyses of coal
 quality.

              PREVIOUS GEOLOGIC WORK

    The western part of T. 2 and 3 S., R. 48 E., of the Pump-
 kin Creek coal deposit was mapped by Bass (1932). The
 eastern part, T. 2 and 3 S., R. 49 and 50 E., was mapped by
 Bryson (1952). The southern part, in T. 4 S., R. 48  and
                                      49 E., was mapped by Warren (1959). A report titled
                                      "Pumpkin Creek Lignite Deposit, Powder River County,
                                      Montana", was presented to the University of Idaho as a
                                      thesis (Carmichael, 1967). The Pumpkin Creek deposit
                                      was also included in reports on strippable coal (Brown
                                      and others, 1954, p. 186-190; Ayler, Smith, and Deutman,
                                      1969).
                                                        LAND OWNERSHIP

                                        The Pumpkin Creek coal deposit lies within the limits
                                      of the land grant of odd-numbered sections to Burlington
                                      Northern,  Inc. The railroad has conveyed much of the
                                      surface but still owns the coal. The State of Montana
                                      owns both the surface and the coal in sec. 16 and 36 of
                                      each township.  The surface of a few scattered tracts is
                                      still owned by the  Federal Government as is most of the
                                      coal, but a small amount of coal along the Pumpkin Creek
                                      valley is privately owned. The western edge of the Pump-
                                      kin Creek coal deposit is bordered by the Custer  National
                                      Forest and is under the administrative supervision of the
                                      U.S. Forest Service.

                                               SURFACE FEATURES AND LAND USE

                                        The  most prominent surface feature is the Pumpkin
                                      Creek valley, which trends slightly east of north  from the
                                      center of T.3 S..R.48E., through T. 2 S., R.48  E. In the
                                      center of T. 3 S., R. 48 E., the valley is divided into a south-
                                      west and  a southeast branch. The southeast branch is
                                      short and heads about 3 miles from the main valley. The
                                      numerous tributaries on the east side of Pumpkin Creek
                                      trend northwest  and those on the west side trend south-
                                      east. These relatively short and steep tributaries are bor-
                                      dered by steep-sided ridges supported by the clinker pro-
                                      duced by burning of the Sawyer coal bed.

                                        Pumpkin Creek and  its tributaries are intermittent
                                      streams and flow only during periods of heavy precipita-
                                      tion  and spring runoff.

-------
                                           Tible 46.-Proximmte analysis, ultimate analysis, heating value, and fusibility of ash, Pumpkin Creek coal deposit.
                                                              Proximate,
Ultimate,
                                                                                      Fusibility of ash. F
Drillhole
and location
PC-3
2S 49E S28
BCDD



PC-9
3S49ES15
BDBA



PC-IS
3S 49E S32
DCCC



PC-23
3S48ES21
CDCC
PC-29
3S48ES3
BCCC
Depth
sampled

68 to
73ft.

123 to
155% ft.

19 to
22ft.

104% to
130% ft.

52 to
64ft.

112 to
124 ft.

105 to
142 ft.

89 to
12 1% ft.
Coal bed & 1
lab. number i
MacUn-Walker

1-21802
Sawyer

1-21803
Macldn-Walker

1-21804
Sawyer

1-21805
Saw/or (in

1-21806
Sawyer (L)

1-21807
Sawyer

1-21808
Sawyer

1-21809
Form
maly
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
                                                 .
                                                              Volatile  Fixed
U = Upper bench of Sawyer

L n Lower bench of Sawyer
analysis  /  Moisture  matter   carbon   Ash   H
                                                      28.84
                                                      31.13
                                                      30.52
                                                      32.21
                                                      30.88
                                                      30.97
                                                      30.15
                                                      30.99
                                                                                                   N
                 Heating   Initial

                  value    deformation   Softening

               S   (Btu)    temp.        temp.
28.88
40.59
48.11
28.48
41.36
4^.90
29.81
42.91
47.12
28.01
41.33
46.19
28.69
41.51
4C Of
27.44
39.75
46.47
28.29
40.50
46.07
28.40
41.16
45.54
31.15
43.77
51.89
33.58
48.75
54.10
33.46
48.16
52.88
32.64
48.14
53.81
33.89
49.03
54.15
31.60
45.78
53.53
33.11
47.40
53.93
33.97
49.22
54.46
11.13
15.64

6.81
9.89

6.21
8.93

7.14
10.53

6.54
9.46

9.99
14.47

8.45
12.10

6.64
9.62

6.26
4.29
5.08
6.51
4.44
4.93
6.55
4.55
5.00
6.58
4.41
4.93
6.43
4.34
4.79
6.39
4.28
5.00
6.37
4.32
4.92
6.49
4.41
4.88
43.33
60.90
72.18
44.78
65.02
72.16
45.73
65.81
72.27
44.14
65.11
72.78
45.27
65.49
72.34
42.71
61.87
72.34
45.18
64.68
73.59
45.51
65.95
72.97

.76
1.07
1

.27
.74
1.07
1

1
1

1
1

1
1

1
1

1
1

1
1
.19
.85
.23
.35
.74
.10
.23
.82
.18
.31
1 S
. ru
.11
.29
.77
.10
.26
.74
.07
.19
37.34
16.44
19.50
40.86
19.15
21.24
39.76
18.18
19.96
40.98
18.23
20.37
40.63
19.08
21.07
39.80
17.76
20.77
38.78
17.15
19.49
40.38
18.61
20.58
1.18
1.66
1.97
.30
.43
.48
.90
1.30
1.42
.42
.62
.69
.31
.45
.49
35
.51
.60
.45
.65
.74
.24
.34
.38
7310
10270
12180
7490
10880
12080
7720
11110
12200
7370
10870
12150
7510
10870
12000
7140
1034U
12090
7550
10810
12300
7570
10970
12140
                           1990
                           2250
                           2410
                           2190
                           2210
                           2080
                           2080
                           2140
                                                                                                2040
                                                                                                2300
                                                                                                2460
                                                                                                2240
                                                                                                2260
                                                                                                2140
                                                                                                2120
                                                                                                2190
Fluid

temp.





2080







2350







2S20







2320







2310







2190







2160







2270
 Real

specific

gravity
 1.59
 1.54
 1.53
 1.55
 1.56
 1.60
 l.Si
 1.55
2
o


o
p

D


i
CO

H
O
jo
n
n
 /A, as received; B, moisture free; C, moisture and ash free.
                                                                                                                                                                        oo

-------
84
STRIPPABLE COAL. SOUTHEASTERN MONTANA
   The low rolling divide between Pumpkin Creek and
Mizpah Creek to the east trends north through the cen-
ter of T. 2 and 3 S., R. 49 E. Tributaries on the west side
of Mizpah Creek trend southeast as do those  of Pumpkin
Creek.

   The principal land use in the area is livestock grazing.
Hay is raised along the flood plains of Pumpkin Creek,
its tributaries, and Mizpah Creek. Some land is cultivated;
winter wheat and other grains are raised by dry-land farm-
ing methods.

               GEOLOGIC STRUCTURE

   The strata in the Pumpkin Creek coal field are almost
horizontal', but a slight dip can be detected  on the cross
sections. The lowest altitude of the top of the Sawyer
coal bed is measured  as  3,350 feet ui drill hole  US-L,
sec. 32, T. 3 S., R. 48 E. Data obtained from drilling of the
Sawyer coal bed show that the strata dip westward 12 to
20 feet per mile, although in places steeper dips are noted.
For example, the dip is southwesterly at 65 feet per mile
between drill hole PC-1 in sec. 13 ana US-C in sec. 22,
T. 2 S., R. 49 E. (Carmichael, 1967, p. 41).

   Although several faults have been mapped in sec. 3,4,
 17,18,32, and 33, T. 3 S., R. 49 E., none have major dis-
placement. A  longer fault system, shown in the eastern
 part of the mapped area, extends more than 20 miles.

                     COAL BEDS

    All strippable reserves that have been mapped in the
 Pumpkin Creek coal deposit are in the two benches of the
 Sawyer coal bed (PI. 15, Section  A-A')- The coal bed
 called the A  bed by Bass (1932,  p. 54) has not been
 mapped in the Pumpkin Creek coal deposit. Carmichael
 (1967) explained that the A bed as defined by Bass is dis-
 tinct in sec. 32, T.  1 S., R. 48 E., but combir es with the
 Sawyer bed somewhere between that point and drill hole
 PC-31, sec. 21, T. 2 S., R. 48 E.,  where the S'-awyer bed
 is 31 feet thick. The Sawyer bed splits in sec. 24, T. 3 S.,
 R. 48 E., where the parting is 1 foot thick  in drill hole
 PC-17. The parting thickens to 15 feet in drill hole PC-22
 near the west line of sec. 33, T. 3 S., R. 48 E. The  split is
 greatest in  the southeastern part  of  the coal deposit,
 where it measured 48 feet in drill hole  PC-15, sec. 32,
 T. 3 S., R. 49 E. There the outcrop of the  low;r bench
 is prominent.

    Numerous  sections of the Mackin-Walker coal bed
 were measured in the northern part of T. 3  S., F'.. 49 E.,
 (Bryson, 1952), where the thickness ranges from 2 feet 3
 inches to 3 feet 11 inches. Farther southwest, th* bed is
                       less than 2 feet thick and too thin to map (Bryson, 1952,
                       p. 85,96). The Mackin-Walker bed was named for a mine
                       in T. 2 S., R.49 E., where the bed is 5 feet thick (Bryson,
                       1952, p. 76).

                                          COAL QUALITY

                          Eight cores of the Sawyer coal bed were obtained dur-
                       ing the field program conducted by the Mineral Develop-
                       ment Division of  Burlington Northern, Inc., and were
                       analyzed by the US. Bureau of Mines, Grand Forks Coal
                       Research Laboratory. Proximate analysis, ultimate analy-
                       sis, heating value, and fusibility of  ash are  shown in
                       Table 46.

                                         COAL RESERVES

                          Coal  reserves in the Sawyer bed total 2,426,500,000
                       tors (Table 45).

                                 FOSTER CREEK COAL DEPOSIT

                                            LOCATION

                          The Foster Creek coal deposit (PI. 16A, B, and C) is in
                       T. 1 and 2 N.,R.46,47,and48 E., and T. 1 and 2 S., R.46,
                       47, and  48 £., Custer and Powder River Counties, about
                       35 miles south of Miles City and directly west of Volborg.
                       The area borders the Pumpkin Creek (PI. 15)  and Little
                       Pumpkin Creek (PI. 27) coal deposits to the south.

                               FIELD METHODS AND MAP PREPARATION

                          The field work on the Foster Creek area was completed
                       during the summer of 1966 under a cooperative agree-
                       ment between the Montana Bureau of Mines and Geology
                       and Burlington Northern, Inc. The field work was under
                       the  supervision  of Virgil  W. Carmichael of Burlington
                       Northern, assisted by Loren A. Williams of Burlington
                       Northern, and by Ernest H. Gilmour of the Montana Bur-
                       eau of f/Iines and Geology. Field methods were those de-
                       veloped by Burlington Northern, Inc.,(Carmichael, 1967).

                                     PREVIOUS GEOLOGIC WORK

                          Most  of the Foster Creek coal deposit was included in
                       the U.S. Geological Survey report on the Ashland coal
                       field (Bass, 1932). Additional information was prepared
                       by Brow.i and  others  (1954), Gilmour and Williams
                       (1969), and Ayler, Smith, and Deutman (1969).

                                          LAND OWNERSHIP

                          The Foi ter Creek coal field lies  within the  land grant
                       to Burlington Northern, Inc. (then the Northern Pacific

-------
                                     INDIVIDUAL DEPOSITS—FOSTER CREEK

               Table 47.-Reserves, overburden, overburden ratio, acres, and tons/acre, Foster Creek coal deposit.
                                                                                                            85
                               TERRET, FLOWERS-GOODALE, AND KNOBLOCH BEDS
  Thickness of
 overburden, ft.
Indicated reserves,
   million tons
     Overburden,
    million cu. yd.
               Overburden ratio,
                cubic yards/ton
                          Acres
                  Tons/acre
    0 to  60
   60 to  90
   90 to 120
              Total
     681.82
     379.78
     366.30
   1,427.90
       1,783.40
       2,274.41
       3427.75
Total   7,585.56
                     2.61
                     5.98
                     9.63
             Average  5.31
                 Total
33,459.2
18,777.6
173472.0
69,708.8
        20.377.7
        20,225.1
        20.964.9
Average  20,483.7
                                                 TERRET BED
    Oto  60
   60 to  90
   90 to 120
              Total
     214.08
     129.57
     117.22
     460.87
Total
 682.15
 941.67
1.389.77
3.013.59
                            3.18
                            7.26
                           11.85
                         12,800.0
                          7,776.0
                          6.886.4
Average  6.53    Total    27,462.4
                   16,725.0
                   16,662.8
                   17.021.9
           Average  16.782.1
                                           FLOWERS-GOODALE BED
    Oto  60
   60 to  90
   90 to 120
              Total
                  Total
        355.04
        514.97
        713.63
       1,583.64
                                      6.662.4
                                      4,249.6
                                      3,532.8
                             Total     14,444.8
                                            17,942.5
                                            17,855.8
                                            17,968.8
                                    Average  17,924.4
                                                KNOBLOCH BED
    Oto  60
   60 to  90
   90 to 120
              Total
                           746.21
                           817.77
                          1,424.35
                   Total   2,988.33
                            2.14
                            4.69
                            7.67
                    Average  4.22
                                      13,996.8
                                       6,752.0
                                       7.052.8
                             Total     27,801.6
                                            24.877.1
                                            25,819.0
                                            26.315.8
                                    Average  25,470.8
Railway). Under the  land grant, the railroad was given
available odd-numbered sections in an area 60 miles on
each side of the railroad right-of-way. Sec. 16 and 36 of
each township were granted to the State of Montana for
school land. The other even-numbered sections were re-
tained by the  Federal  Government until either home-
steaded or sold.


   Burlington Northern has retained most of the mineral
rights although it has conveyed the surface ownership.
The State of Montana has retained all surface and mineral
rights. The Federal Government, although it has sold or
allowed homesteading of the  surface,  has retained the
mineral rights.
                                                  SURFACE FEATURES AND LAND USE

                                           Surface features in the Foster Creek coal field range
                                        from the  broad, nearly level valley of the lower reach of
                                        Pumpkin Creek and its west tributaries, to the steep-sided
                                        rugged  ridges between drainages.  The burning  of the
                                        Knobloch  and Flowers-Goodale coal beds has created
                                        clinker, which forms precipitous slopes  near  the  ridge
                                        lines. Foster Creek, which heads in the southern part of
                                        T. 1  N., R.47 E., and flows northward, is an intermittent
                                        stream and carries water only during periods of heavy
                                        precipitation and spring runoff. Pumpkin Creek has pools
                                        of water  all year but has periods of no flow.  Except
                                        where dammed, the  west tributaries of Pumpkin Creek
                                        are dry.

-------
                                            Table 48.-Pnndnute uutyfif, ultimate analyib, and heating value, Potter Creek coal depodt.
  Drillhole
 and location
 FC-6
 IS 48E S29
 AADD

 FC-11
 IS 47E S3
 ACAC
FC-16
1N48ES17
CABB

FC-28
1N47ES21
ACBC
FC-29
1N46ES21
BCCB
FC-32
1N47ES25
CCCC
 Depth
 sampled
 48 to
 59ft.
 84 to
 100 ft.

 212 to
 220 ft.
 53 to
 62ft.
 37 to
 38ft.

 74 to
 87ft.

197 to
208ft.

115 to
117ft.
118 to
121ft.
 83 to
95V4 ft.

177 to
186£ ft.
  Lab.
 number
1-46486
1-46487
                             1-46488
1-46489
1-46490
                             1-46491
                             1-46492
1-46493
1-46494
                             1-46495
  Coal
  bed
                          Knobloch
                          Knobloch
                                           Flowers-
                                           Goodale
                          Terret
                          Lay Creek
              Flowers-
              Goodale

              Terret
              Knobloch
Flowers-
Good ale

Terret
Proximate. %
Form of
analysis '
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
Volatile
/ Moisture matter
33.14 27.09
40.52
45.00
30.62 27.96
40.29
45.81
31.29 26.20
38.13
42.65
30.46 27.37
39.35
42.49
28.45 27.86
38.93
46.86
30.25 26.62
38.16
43.83
30.05 26.58
37.99
41.72
29.58 28.17
40.00
45.60
31.54 26.98
39.41
44.10
31.63 26.75
39.13
43.06
Fixed
carbon
33.11
49.52
55.00
33.06
47.66
54.19
35.23
51.27
57.35
37.03
53.25
57.51
31.58
44.14
53.14
34.11
48.91
56.17
37.12
53.08
58.28
33.60
47.71
54.40
34.21
49.96
55.90
35.38
51.75
56.94
Ash
6.66
9.96

8.36
12.05

7.28
10.60
5.14
7.40

12.11
16.93
9.02
12.93
6.25
8.93
8.65
12.29

7.27
10.63

6.24
9.12

S
0.37
0.56
0.62
0.32
0.46
0.52
0.40
0.59
0.66
0.21
0.30
0.32
0.39
0.54
0.65
0.77'
1.11
1.27
0.24
0.35
0.38
1.61
2.28
2.60
0.36
0.53
0.60
0.20
0.30
0.33
H
6.50
4.21
4.68
6.53
4.50
5.12
6.44
4.30
4.81
5.95
3.69
3.99
6.33
4.43
5.33
6.26
4.16
4.77
6.11
3.98
4.37
6.35
4.36
4.97
6.45
4.30
4.81
6.25
4.00
4.40
Ultimate. %
C
44.29
66.25
73.59
45.11
65.01
73.92
45.49
66.20
74.05
47.78
68.70
74.19
43.73
61.11
73.56
45.07
64.62
74.22
47.59
68.04
74.71
46.36
65.84
75.05
44.96
65.67
73.48
46.16
67.52
74.30
N
0.71
1.07
1.18
0.71
1.02
1.16
0.71
1.04
1.16
0.75
1.08
1.16
0.70
0.98
1.18
0.71
1.02
1.17
0.73
1.04
1.14
0.75
1.07
1.22
0.70
1.03
1.15
0.70
1.02
1.12
Heating
O value (Btu)
41.47
17.95
19.93
38.97
16.96
19.28
39.68
17.27
19.32
40.17
18.83
20.34
36.74
16.01
19.28
38.17
16.16
18.57
39.08
17.66
19.40
36.28
14.16
16.16
40.26
17.84
19.96
40.45
18.04
19.85
7380
11040
12260
7500
10810
12290
7550
109*90
12290
7820
11240
12140
7360
10280
12380
7570
10860
12470
7860
11240
12350
7840
11140
12700
7540
11010
12320
7630
11150
12270





co
3
fPPABLE COt
r
CO
0
g
i
EASTERN
MONT A*
«4








1
 /A, as received; B, moisture free; C, moisture and ash free.

-------
                                                     Table 49.-Fomu of sulfur and fusibility of ash, Foster Greek coal deport.
 Drillhole
and location
 Depth
sampled
 Lab.
number
Coal
bed
                                                                               Form of sulfur. %
Form of.
analysis  /  Sulfur      Sulfate
         Pyritic
Organic
                                                                                                      Fusibility of ash. F
  Initial
deformation    Softening   Fluid
  temp.        temp.      temp.
FC-6
1S48ES29
AADD

FC-11
IS 47E S3
ACAC
FC-32
IN 47E S25
OCCC
 48 to
 59ft.
 84 to
100ft.

212 to
220 ft.
1-46486



1-46487


1-46488
FC-16
1N48ES17
CABB
FC-28
1N47ES21
ACBC


FC-29
1N46ES21
BCCB
53 to
62ft.
37 to
38ft.
74 to
87ft.
197 to
208ft.
115 to
117ft.
118 to
121 ft.
1-46489
1-46490
M6491
1-46492
1-46493
 83 to
            1-46494
177 to
186 K ft.    1-46495
                          Knobloch
                          Knobloch
                                           Flowers-
                                           Goodale

                                           Tenet
                                           Lay Creek



                                           Flowers-
                                           Goodale

                                           Tenet


                                           Knobloch
                          Flowers-
                          Goodale
                                           Tenet
             A
             B
             C

             A
             B
             C
             A
             B
             C

             A
             B
             C

             A
             B
             C
             A
             B
             C
             A
             B
             C

             A
             B
             C
                             A
                             B
                             C
                             A
                             B
                             C
              .37
              .56
              .62

              .32
              .46
              .52
              .40
              .59
              .66

              .21
              .30
              .32

              .39
              .54
              .65
              .77
             1.11
             1.27
              .24
              .35
              .38

             1.61
             2.28
             2.60
                        .36
                        .53
                        .60
                        .20
                        .30
                        .33
.03
.04
.04

.01
.02
.02
.03
.05
.05

.01
.02
.02

.02
.03
.03
.02
.03
.04
.02
.03
.04

.02
.03
.04
                         .02
                         .02
                         .02
                         .00
                         .00
                         .00
.13
.20
.22
.07
.10
.11
.07
.11
.12
.03
.04
.04
.03
.04
.05
.55
.78
.90
.13
.18
.20
1.21
1.72
1.97
.21
.32
.35
.24
.34
.39
.30
.43
.49
.17
.24
.26
.34
.47
.57
.20
.29
.34
.12
.16
.18
.37
.52
.60
            .07
            .11
            .12
            .02
            .03
            .03
 .28
 .40
 .45
 .18
 .27
 .23
  2290



  2230


  2190



  2250



  2440


  2050


  2030



  2000




  2210


  2040
                           2320



                           2260


                           2240



                           2280



                           2470


                           2100


                           2080
          2350



          2290


          2290



          2310



          2500


          2190


          2180
                                                                                                               2050      2140
2240      2270
                                                                                                                                2150       2260
1
 /A, as received; B, moisture free; C, moisture and ash free.
                                                                                                                                                          oo

-------
                                                           Ttble 50.-Major ash constituents, Foster Creek coal deposit.
                                                                                                                                                                oo
                                                                                                                                                                oo
Drillhole      Depth      Sample       Coal
Constituent.
and location
FC-11
IS 47E S3



FC-28
IN 47E S21

FC-32
1N47ES25


sampled
84 to
100 ft.

212 to
220 ft.
74 to
87ft.
197 to
208 ft.
83 to
95% ft.
177 to
186% ft.
number
GF-66-
1200

GF-66-
1202
GF-66-
1205
GF-66-
1208
GF-66-
1211
GF-66-
1213
bed
Knobloch


Flowers-
Goodale
Flowers-
Goodale
Tenet
Flowers-
Goodale
Tenet

A12O3 CaO FejO3 K2O MgO Na2O P2O5 SiO3 SO3 TiO2
14.3 18.3 4.7 .3 5.9 1.0 .7 43.1 8.7 .7


14.3 21.3 6.2 .3 4.7 6.2 .1 29.9 12.7 .5

13.5 18.7 9.5 .4 3.8 5.5 .1 28.0 19.4 .3

12.8 24.8 7.9 .3 5.0 8.8 .6 26.2 11.9 .3
17.2 22.6 6.1 .4 4.9 4.5 .6 30.3 11.8 .5

11.9 24.9 7.0 .3 4.7 8.4 1.2 30.3 8.9 .3

LOI @ 800°C Total
.5 98.2

U)
.5 96.7 jjj
>
.5 99.7 w
0
o
p
.4 99.0 g
.3 99.2 i
i
.8 98.7 |
3

-------
                                      INDIVIDUAL DEPOSITS—BROADUS
                                                                                                        89
   The principal land uses in this area are livestock graz-
ing and dry-land farming. Many areas provide large gently
sloping fields for raising winter wheat and  other grains.
Hay  is grown on meadows along the principal valleys
throughout the area.

               GEOLOGIC STRUCTURE

   The regional dip in the Foster Creek area is southwest,
as the Terret bed declines from an altitude of 3,150 feet
in the northern part to 3,070 feet in the part south of
Little Pumpkin  Creek. Small anticlinal and  synclinal un-
dulations have vertical relief as great as 60 feet (Gilmour
and Williams, 1969, p. 3).

                    COAL BEDS

   The three major  coal beds in the Foster Creek area
are, from lowest to highest, the Terret, Flowers-Goodale,
and the Knobloch. The Terret bed is the principal coal
bed in the northern part of the area, where the thickness
averages about 9 feet over a large area and is a maximum
of 11 feet. In the southern half of the mapped area, both
the Flowers-Goodale and the Knobloch beds are minable.
The Flowers-Goodale is 2 to 14 feet thick, and the Knob-
loch  is 5 to 18 feet thick. In the southern part of the
area, the  vertical distance between the Flowers-Goodale
and the Knobloch, as determined by drilling, is 89 to  119
feet (Gilmour and Williams, 1969, p. 3).

                   COAL QUALITY

   Ten core samples were recovered during the  field in-
vestigations and were sent to the Grand Forks Coal  Re-
search Laboratory, US.  Bureau of Mines, for analyses.
Proximate analysis, ultimate analysis, and heating value
are shown in Table 48. Forms of sulfur and fusibility of
ash are shown in Table 49, and major ash constituents in
Table 50.

                   COAL RESERVES

   The coal reserves  in  the Foster  Creek area total
1,427,900,000 tons.  The Knobloch  coal bed  contains
708,130,000 tons, the Flowers-Goodale bed 258,900,000
tons, and the Terret bed 460,870,000 tons (Table 47).

             BROADUS COAL DEPOSIT

                     LOCATION

   The Broadus coal deposit (PI. 17) is in T. 2,3, and 4 S.,
R. 49 and  50 E.,  Powder River County, about 5 miles
northwest of Broadus. The area is bordered on its eastern
 side by U.S. Highway 312, which connects Broadus with
 Miles City. U.S. Highway 212 cuts across the southern
 part of the mapped area. The Broadus coal deposit over-
 laps the Pumpkin Creek coal deposit (PI. 15) to the west
 and borders the Foster Creek coal deposit (PI. 16). The
 Sand Creek coal deposit (PL 28) is a few miles to the
 north.

        FIELD WORK AND MAP PREPARATION

   The  field work in the Broadus coal deposit was done
 in the summer of 1967 as part of a cooperative  project
 between Burlington  Northern,  Inc., and the Montana
 Bureau  of Mines and Geology to develop information on
 strippable coal in eastern Montana. Both the railroad and
 the Bureau supplied a field crew and shared in the drilling
 expenses. Loren A. Williams of Burlington Northern, Inc.,
 prepared the map from field data during the following
 winter.

   The field method was developed by Burlington North-
 ern, Inc., to evaluate strippable coal in areas where good
 topographic maps were lacking. This method included
 establishing  a  series  of temporary bench marks of the
 area as well as altimeter base stations, and obtaining hun-
 dreds of altimeter points for topographic control. Infor-
 mation  on the quantity and quality of the coal was ob-
 tained by drilling (Carmichael, 1967).

             PREVIOUS GEOLOGIC WORK

   The  northern part of the Broadus coal deposit was
 mapped by  Bryson  (1952), and the southern part by
 Warren (1959). The part that is overlapped by  the Pump-
 kin Creek coal deposit  was mapped and described in a
 thesis by  Carmichael  (1967). Strippable coal  in  the
 Broadus coal bed was  included  in a report  by Ayler,
 Smith, and Deutman (1969, p.  23), but that report in-
 cluded an area farther south  in T. 5 and 6 S., R. 49 and
 50 E., which was excluded from the present  report be-
 cause the  topography  there is  rugged  and deeply dis-
 sected. Some small areas, however, as along Rough Creek
 and  Cache Creek, would provide some  strippable coal.
The  Cache Creek strippable coal deposit in the Broadus
 coal bed has been described by Matson, Dahl, and Blumer
(1968).

                 LAND OWNERSHIP

   As T. 2 and 3 S., R. 49 and 50 E., are within the land
grant to Burlington Northern, Inc., the railroad owns the
coal in the odd-numbered sections, although it has con-
veyed most of the surface. In T. 4 S., R. 49  and 50 E.,
south of the land grant,  most of the coal  is owned by the

-------
90
              STRIPPABLB GOAL, 8OUTHBA8TBRN MONTANA
                   Table Sl.-Rewnrw, overburden, overburden ratio, tens, tnd toiu/acre, Broadus coal deposit.
                                                 BROADUSBED
    Thickness of
    uveibuiiien, ft.
Indicated reiervei,
   million tons
 Overburden,
million cu. yd.
Overburden ratio,
 cubic yards/ton
Acres
Tons/acre
       Oto  50
      SO to 100
     100 to 150
                Total
     165.92                224.14
     226.83                701.31
     347.07               1.793.59
     739.82        Total   2,719.04
                       1.35
                       3.09
  Federal Government, although the surface has been con-
  veyed except for a few small tracts. The state owns sec. 16
  and 36 in each township in T. 2 and 3 S., but only a frac-
  tion of those sections in T. 4 S.

           SURFACE FEATURES AND LAND USE

    The Broadus coal field on the west side of the broad
  alluviated Mizpah valley, is drained by Mizpah Creek and
  its tributaries. The area has moderate to low  relief, and
  the terrain is gently  sloping except for a few steep-sided
  ridges, small  mesas, and  buttes.  The Broadus bed has
  burned in large areas where it was under a minimal over-
  burden and the burning  has formed thick multicolored
  clinker along the eastern edge of the coal deposit. Locally
  the  clinker is deeply dissected. Mizpah Creek, an inter-
  mittent stream flowing most of the year, has periods of
  no flow in the late  summer and autumn. Its tributaries
  are dry, and water is retained only by earthen dams.

    The principal land uses are livestock grazing and dry-
  land farming. The gently sloping terrain above the clink-
  ered areas provides large fields suitable for raising winter
  wheat and other  grains.  Hay is  raised in sub-irrigated
  fields along the main valley of Mizpah Creek and its trib-
  utaries.

                 GEOLOGIC STRUCTURE

     The strata in the Broadus coal deposit dip generally
  westward. Minor structural undulations roughly parallel
  the land surface; the tributaries west of Mizpah Creek are
  structurally low and the ridges between are structurally
  high. A fault  has been mapped in sec. 10 and IS, T. 4 S.,
  R. 50 E. (Warren, 1959).

                       COAL BEDS

     The Broadus bed is the only bed in the Broadus coal
  deposit that  has  strippable reserves. Farther wot the
  Sawyer coal  bed. which overlies the Broadus, has been
  mapped and included in the Pumpkin Creek coal deposit
  (PL  15). In the Broadus coal field the Broadus bed is 100
  feet above the base of the Tongue River Member (Warren*
               Avenge  3.68     Total
                      3,737.2            44,396,87
                      5,796.0            39,135.61
                      8.896.6            39.011.53
                     18,429.8     Avenge 40,142.15
                                       1959; Matson,  Dahl, and Blunter, 1968), but farther
                                       north, in the Coalwood field, it is 135 feet  above the
                                       base (Bryson, 1952). The thickness of the Broadus coal
                                       bed is 26 feet in drill hole BR-1C, sec. 5, T. 4 S., R. 50 E.,
                                       and at the abandoned  Peerless mine, sec. 23, T. 4 S.,
                                       R. SO E. The bed splits and thins northward, as shown in
                                       drillhole BR-7C, sec. 16.T.2 S., R. 50 E., and in drill hole
                                       BR-10, sec. 13, T. 2 S., R. 49 E. In drill hole BR-8, sec. 4,
                                       T. 2 S., R. 50 E., in the northern end of the deposit, the
                                       bed consists of two 5-foot benches. The Broadus coal
                                       bed also thins to the south and is 12 feet thick in drill
                                       hole SS-2, sec. 36, T. S S., R. 49 E. (Matson, Dahl, and
                                       Blunter, 1968, p. 41).

                                          A local bed between the Broadus and the Sawyer coal
                                       beds is as much as S feet thick, as shown in drill hole BR-9
                                       insec.36,T.2S.,R.49E.

                                                         COAL QUALITY

                                          Small wagon mines, including the Peerless in the south-
                                       central part of sec. 23, T. 4 S., R. SO £., the Victor Stabio
                                       in sec. 24, T. 4 S., R. SO EM the Black Diamond in sec. 1 1 ,
                                       T. S S., R- 50 E., and the Superior in sec. 14, T.  S S.,
                                       R. 50 E., were actively supplying the needs of the Broadus
                                       community in earlier years. Analytical reports  of samples
                                       from these mines show a heating value ranging from 6,390
                                       to 7380 Btu, moic&ue 29.0 to 319%, volatile matter
                                       266 to 31.6%, fixed carbon 313 to 33.1%,  ash 6.0 to
                                       8.1%, and sulfur 02 to QA% on the "as received"  basis
                                       (Warren, 1959).

                                          Four cone sample* were obtained  from the Broadus
                                       coal bed, and these were analyzed by the US. Bureau of
                                       Mines, Grand FodU Coal Research Laboratory. Proximate
                                       anah/afe, ultimate analysis, and heating value  are shown
                                       in Table 52, and major aft constituents and fusibility of
                                       attaieafe0wnfaiT0Me53.
                                          Reserve* in Jh* ffroa&c coal deport total 739,820,000

-------
Tible 52.-Pn»dmate analysis, ultimate analysis, ind betting value, Braadus coal deposit
Proximate. %
fidDfaflfe
and location
BR-1C
4S5QES5
BOCD
BR-6C
3SSOES7
AAAB
BR-7C
2S5QES16
CCCC
BR-12C
3S50ES5
AABB

Depth
sampled
'
68 to
94ft.

92 to
U7 ft.

89 to
104ft.

£7 to


Lab. Coal Form of .
number bed analysis / Moisture
Broadui A 30.07
B
1-73087 C
Broadui A 28.95
B
1-73088 C
Broadui A 30.87
B
1-73089 C
Broadui A 29.82
B
1-73090 C

Volatile
matter
28.67
41.00
45.11
28.86
40.62
44.99
27.58
39.90
45.92
28.81
41.05
45.27

Fixed
carbon
34.89
49.89
54.89
35.29
49.67
55.01
32.48
46.98
54.08
34.83
49.63
54.73


Ash S
6.37 .19
9.11 .27
.30
6.90 .24
9.71 .34
.37
9.07 .46
13.12 .66
.76
634 .20
9.32 .29
.32

Ultimate. %

H
6.39
4.36
4.80
6.26
4.29
4.76
6.39
4.28
4.93
6.38
4.38
4.83


C
45.69
65.34
71.89
45.82
64.50
71.44
42.79
61.89
71.24
45.19
64.39
71.00


N
.67
36
1.05
.67
54
1.04
.70
1.02
1.17
.68
.97
1.06


O
40.69
19.96
21.96
40.11
20.22
22.3»
40.59
19.03
21.90
41.01
20.65
22.79

HnnHtifl
value (Btu)
7580
10840
11930
7550
10630
11780
7120
10310
11860
7500
10680
11780












2
g

-------
92
                                 STRIPPABLE COAL, SOUTHEASTERN MONTANA

                Table 54.-Reserves, overburden, overburden ratio, acres, and tons/acre, East Moorhead coal deposit.
                                                    TBED
    Thickness of
   overburden, ft.
Indicated reserves,
  million tons
 Overburden,
million cu. yd.
  Overburden ratio,
   cubic yards/ton
        Acres
                   Tons/acre
       Oto 50
      50 to 100
     100 to 150
               Total
                  Total
    188.13
    611.63
   1.215.70
   2,015.46
         EAST MOORHEAD COAL DEPOSIT

                     LOCATION

   The East Moorhead coal deposit (PI. 18) is in T. 7, 8,
 and 9 S., R. 50 and  51 E., Powder River County. The
 area is bounded on the east by exposure and by clinker
 above the T coal bed, on the south by the Wyoming bor-
 der, and on the west by increasingly thicker overburden.

         FIELD WORK AND MAP PREPARATION

   The field work in the East Moorhead coal deposit was
 done during the summer of 1971; numerous exploration
 holes were drilled and the surface was mapped on 7&-
 minute topographic quadrangle maps. Mapping was com-
 pleted the following winter, when the overburden map
 was prepared.

              PREVIOUS GEOLOGIC WORK

    The East Moorhead coal deposit was  described in  a
 U.S. Geological Survey open-file report on the Moorhead
 coal field (Bryson and Bass, 1966).

                  LAND OWNERSHIP

    The Federal Government owns most of the coal rights
 in the deposit, as the area is south of the land grant to
 Burlington Northern, Inc., but it has conveyed  most of
 the surface to individuals  except in T. 8 S. The  State of
 Montana owns the surface and coal in sec. 16 and 36 in
 each township.

          SURFACE FEATURES AND LAND USE

    The East Moorhead coal deposit occupies the highest
 part of the divide between Little Powder River to the east
 and Powder River to the west.  All  the  tributaries of
 Powder River and Little  Powder River are intermittent
 streams, which flow  only during periods  of heavy pre-
 cipitation  and the spring runoff. Because the drainage
 pattern has a very strong  northwest to north orientation
 on both sides of  the divide, it seems to be  structurally
        1.62
        3.46
        5.23
Average  3.84
Total
 3,533.7             32,883.4
 5,054.8             34,931.8
 6.970.9             33.341.0
15,559.4     Average  33,756.0
                                      controlled. The divide area is grass-covered and gently
                                      rolling above the clinker areas. The steep valley sides are
                                      formed by resistant clinker produced by burning of the
                                      T coal bed. The valley bottoms are relatively flat and the
                                      main ones are as much as a mile wide. Buttes are numer-
                                      ous in the area and are capped by clinker. Ponderosa pine
                                      trees grow on the clinker along the sides of the valleys.

                                        The principal land uses in the area are livestock grazing
                                      and dry-land farming. Various grains are grown  on sum-
                                      mer fallowed fields, and some hay is raised, especially
                                      along the valley bottoms.

                                                     GEOLOGIC STRUCTURE

                                        Drill hole data from the T coal bed show a dip to the
                                      west. Minor undulation of  the surface is apparent in the
                                      area.

                                                          COAL BEDS

                                        The T coal bed, the only one in the East Moorhead
                                      coal deposit that contains economically recoverable coal,
                                      has been correlated (Bryson and Bass,  1966) with the
                                      Cache coal bed. It is named  for Cache Creek  west of
                                      Powder River (Warren, 1959). The T coal bed is 26 feet
                                      thick in drill hole SH-713 in sec. 6, T. 8 S., R. 51 E., in
                                      the north-central part of  the mapped  area, but thins
                                      southward and is only 10 feet thick in drill hole SH-718
                                      insec.24,T.9S.,R.50E.

                                                         COAL  QUALITY

                                        Thirteen core samples were obtained from the T coal
                                      bed for analyses by the Montana Bureau of Mines and
                                      Geology analytical laboratory. Proximate analysis, forms
                                      of sulfur, and heating value are shown in Table 55, and
                                      major ash constituents of composite samples are shown
                                      in Table 56.

                                                        COAL RESERVES

                                         Reserves in the T coal bed total 525,210,000 tons
                                      (Table 54).

-------
                                         Table SS.-Ptoximate analysis, forms of sulfur, and heating value, East Mooihead coal deposit.
 Drillhole
and location
SH-711
8SRS1ES4
BADC
SH-712
8SRS1ES9
BCAB
SH-713
8SRS1ES6
DDAD
SH-714
8SR51ES30
DBBA
SH-716
8S RSOE S36
BADC

SH-718
9S RSOE S24
BBCA

SH-719
9SR50ES19
ABAD
 Depth
sampled
 90 to
 98ft.

 98 to
104ft.
ISO to
158 ft.

158 to
161 ft.

161 to
168 ft.
103 to
112ft.

112 to
122 ft.
 21 to
 30ft.

 30 to
 36ft.
 50 to
 60ft.
 90 to
 96ft.
160 to
170 ft.

170 to
175 ft.
 Lab.
number
 343


 344



 345


 346


 34->



 348


 349



 350


 351



 352



 353



 354


 355
Coal
bed
Proximate. %
Form of i
analysis /
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

Moisture
37.870

36.820


37.650


37.070


37.270


36.690


36.630


38.360


36.310


33.940


33.730


34.640


31.840


Volatile
matter
27.453
44.187
48.102
29.516
46.717
50.753
27.567
44.213
48.325
27.449
43.618
47.143
26.675
42.524
45.608
27.647
43.669
47.091
26.937
42.507
45.521
26.334
42.722
46.225
27.614
43.357
48.425
29.111
44.068
47.844
27.239
41.103
49.785
27.474
42.035
46.029
19.821
29.081
36.033
Fixed
carbon
29.620
47.673
51.898
28.640
45.331
49.247
29.478
47.279
51.675
30.776
48.905
52.857
31.813
50.714
54.392
31.063
49.064
52.909
32.237
50.872
54.479
30.635
49.701
53.775
29.410
46.178
51.575
31.735
48.040
52.156
27.474
41.458
50.215
32.215
49.289
53.971
35.187
51.625
63.967

Ash
5.057
8.140
5.024
7.952

5.304
8.508

4.705
7.477

4.242
6.762

4.601
7.267

4.796
6.621

4.671
7.577

6.666
10.466

5.213
7.892

11.557
17.440

5.671
8.676

13.151
19.294


Sulfur
.675
1.086
1.182
.367
.581
.631
.674
1.081
1.182
.434
.690
.745
.314
.500
.537
.741
1.171
1.263
.321
.507
.543
.476
.772
.835
.762
1.197
1.337
.360
.545
.592
.580
.875
1.059
.546
.835
.914
1.181
1.732
2.146
Form, of sulfur. %

Sulfate
.028
.046
.050
.022
.036
.039
.015
.024
.026
.015
.024
.026
.015
.024
.026
.015
.023
.025
.022
.035
.038
.021
.035
.037
.030
.047
.053
.017
.026
.028
.017
.025
.031
.017
.026
.029
.017
.025
.031

Pyritic
.071
.114
.124
.007
.012
.013
.111
.178
.195
.107
.169
.183
.061
.098
.105
.015
.023
.025
.007
.012
.013
.199
.322
.349
.536
.842
.940
.077
.117
.402
.134
.203
.246
.162
.248
.271
.362
.531
.658

Organic
.575
.926
1.008
.337
.533
.579
.548
.879
.961
.312
.496
.536
.237
.378
.406
.712
1.125
1.213
.291
.459
.492
.256
.415
.449
.196
.308
.344
.266
.402
.437
.428
.646
.783
.367
.561
.614
.801
1.176
1.457
Heating
value (Btu)
6994
11258
11255
7059
11172
12137
7014
11250
12296
7112
11301
12214
7134
11373
12198

7208
11386
12278
7147
11278
12078

6943
11264
12188
7051
11071
12366

7592
11493
12477
6867
10362
12551
7494
11465
12554
6947
10192
12629














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-------
Table 56. -Major ash constituents of composite samples, East Moorhead coal deposit.
Drill hole
and location
SH-711
8SS1ES4
BADC
SH-712
8S51ES9
BCAB

SH-713
8S51ES6
DDAD

SH-714
8S51ES30
DBBA
SH-716
8S 50E S36
BADC


SH-718
9S 50E S24
BBCA
SH-719
9S50ES19
ABAD
Depth Lab. Coal Constituent, %
sampled sample bed A1203 CaO Fe2O3 K2O MgO Na2O P2O5 SiO2 SO3 TiO2 Total
T 9.5 34.3 6.6 .1 6.1 2.3 .7 13.8 21.3 .3 95.0
90 to
104 ft. 343-344
T 12.1 34.1 6.3 .1 6.4 1.6 .1 17.7 16.6 .4 95.4
150 to
168 ft. 345-347

T 12.0 31.9 5.6 .1 6.3 4.5 1.8 12.0 21.0 .3 95.5
103 to
122 ft. 348-349

T 9.4 20.5 10.5 .1 5.0 1.1 1.1 17.7 21.5 .4 87.3
21 to
36ft. 350-351
T 14.9 33.8 6.8 .1 6.0 1.0 2.0 16.5 14.0 .4 95.5
50 to
60 ft. 352


T 24.4 12.4 5.5 1.0 2.7 1.3 .9 42.8 5.8 1.0 97.8
90 to
96 ft. 353
T 17.4 16.5 8.9 .5 3.1 1.6 1.1 32.1 15.8 .6 97.6
160 to
175ft. 354-355





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-------
                                     INDIVIDUAL DEPOSITS—DIAMOND BUTTE
                                                                                                              95
                           Table 57.-Reserves, overburden, overburden ratio, acres, and tons/acre,
                              Diamond Butte, Goodspeed Butte, and Fire Gulch coal deposits.
                                                  CANYON BED
   Thickness of
   overburden, ft.
Indicated reserves,
   million tons
     Overburden,
    million cu. yd.
               Overburden ratio,
                cubic yards/ton
                         Acres
                   Tons/acre
Oto 50
SO to 100
100 to 150
Total
139.21
178.78
100.03
418.02
                                     Total
417.74
1,116.38
864.26
2,398.38
3.00
6.24
8.64
Average 5.74
                                                              7,848.2
                                                              9,228.2
                                                              4.287.2
                                                      Total   21,363.6
                                                               17,737.8
                                                               19,373.2
                                                               23.332.2
                                                       Average  19,566.6
                                                   COOK BED
Thickness of
overburden, ft.
Oto 50
50 to 100
100 to 150
Indicated reserves,
million tons
128.11
225.67
275.17
Total 628.95
                                     Total
                                          Interburden,
                                         million cu. yd.
                           288.3
                           848.69
                         1.492.08
                         2,629.07
                                        Overburden ratio,
                                         cubic yards/ton
                            2.25
                            3.76
                            5.42
                   Average  4.18     Total
                                             Acres             Tons/acre
                                     2,688.0             47,659.9
                                     4,710.4             47.908.9
                                     6.047.8             45.499.2
                                    13,446.2     Average  46,775.9
                                             PAWNEE and COOK BEDS
   Thickness of
  overburden, ft.
Indicated reserves,
  million tons
   Overburden and
     interburden,
    million cu. yd.
               Overburden and
               interburden ratio,
                cubic yards/ton
                                                               Acres
                                           Tons/acre
      Oto  50
     50 to 100
    100 to 150
               Total
      73.28
     152.03
     111.38
     336.69
Total
 200.89
 529.71
 749.6
1,480.2
        2.74
        3.48
        6.73
Average  4.39
                                                                        Total
2,035.2             36,006.3
3,699.2             41,098.1
2.752.0             40.472.4
8,486.4     Average  39,674.1
   DIAMOND BUTTE, GOODSPEED BUTTE, AND
           FIRE GULCH COAL DEPOSIT

                      LOCATION

   The Diamond Butte (PI. 19), Goodspeed Butte (PI. 20),
and Fire Gulch (PI. 21) coal deposits are in T. 6 and 7 S.,
R. 46,47, and 48 E., Powder River County. These depos-
its are bordered on the south by the West Moorhead (PI.
10A,  B, and  C), on the north by the Threemile Buttes
(PI. 24) and Sonnette (PI. 25A and B), and on the north-
west corner by the Otter Creek (PI. 12) coal deposits.
Parts of the Fire Gulch and Diamond Butte deposits are
outside the boundary, but most of the coal in these three
deposits is in the Custer National Forest.
                                                FIELD WORK AND MAP PREPARATION

                                         The Diamond Butte, Goodspeed Butte, and Fire Gulch
                                       areas were drilled during the 1971 field season. The geol-
                                       ogy was mapped from colored photos borrowed from the
                                       U.S. Forest Service,  supplemented by reference to the
                                       report by Warren (1959).

                                                    PREVIOUS GEOLOGIC WORK

                                         Except for T. 7 S., R. 46 and 47 E., the area included
                                       in the Diamond Butte, Goodspeed Butte, and Fire Gulch
                                       deposits was mapped by Warren (1959). That part of the
                                       area that is in T. 7 S., R. 45 and 46 E., was described by
                                       Bryson and Bass (1966), and by Matson (1970), and the

-------
                                            Table 58.-Proximate analysis, forms of sulfur, and heating value, Diamond Butle coal deposit.
                                                                                                                                                                   Os
   Drill hole
 and location
 SH-7121
 6SR48ES16
 BCAA

 SH-7122
 6S R47L- S34
 CCCD
 SH-7123
 6S R471 S29
 DACC

 SH-7124
 6S R47E S30
 BCBB

 SH-7128
 6S R47fc S36
 ACAC

SH-7134
6S R48E S29
BBAA
  Depth       Lab
 sampled     number
  90 to
  96ft
  88 to
  90ft.

 174 to
 178ft
192 to
201 ft.
 56 to
 63ft
112 to
122 ft.
 54 to
 64ft
             376
                                 377
                                 378
             379
            380
            383
                                384
Coal
bed
                       Canyon
                       Local
                                                                                Proximate, %
                                                                                                   Form of sulfur, %
                       Canyon
                       Canyon
                       Canyon
                      Canyon
Form of
analysis  /
             A
             B
             C

             A
             B
             C
             A
             B
             C

             A
             B
             C

             A
             B
            C

            A
            B
            C

            A
            B
            C

Moisture
37.030


36.400


34.070


34.430


32.270


36.650


35.260


Volatile
matter
27.510
43.687
46.736
25.542
40.160
44.154
27.603
41.868
47.864
28.539
43.524
46.149
29.335
43.311
45.526
26.294
41.507
43.787
27.929
43.140
46.874
Fixed
carbon
31.352
49.788
53.264
32.305
50.793
55.846
30.068
45.605
52.136
33.301
50.787
53.851
35.100
51.823
54.474
33.757
53.286
56.213
31.654
48.894
53.126

Ash
4.109
6.525

5.754
9.047

8.259
12.527

3.730
5.689

3.296
4.866

3.299
5.207

5.157
7.966


Sulfur
.274
.435
.465
.493
.775
.852
1.017
1.543
1.764
.264
.402
.427
.262
.387
.407
.213
.336
.354
.523
.808
.878

Sulfate
.007
.012
.013
.000
.000
.000
.015
.023
.026
.008
.011
.012
.016
.023
.025
.007
.012
.012
.014
.022
.024

Pyritic
.059
.094
.101
.077
.121
.133
.528
.800
.915
.023
.034
.037
.016
.023
.025
.044
.069
.073
.122
.188
.204

Organic
.207
.329
.352
.416
.654
.719
.475
.720
.823
.234
.356
.378
.230
.340
.357
.161
.255
.269
.387
.597
.649
                                                                                                                                              CO
                                                                                                                                              H
 Heating
value (Btu)
                                                                                                   7138
                                                                                                  11336
                                                                                                  12127

                                                                                                   7100
                                                                                                  11164
                                                                                                  12274
                                                                                                   7240
                                                                                                  10981
                                                                                                  12553

                                                                                                   7455
                                                                                                  11369
                                                                                                  12055

                                                                                                   7897
                                                                                                  11660    w
                                                                                                  12257    W
                                                                                                           2
                                                                                                   7187    S
                                                                                                  11345    |
                                                                                                  11968    £

                                                                                                   7296    >
                                                                                                  11269
                                                                                                  12245
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 /A, as received; B, moisture free, C, moisture and ash free.

-------
Table 59.-Major ash constituents, Diamond Butte coal deposit.
Drill hole
and location

SH-7121
6S48ES16
BCAA
SH-7122
6S 471£ S34
CCCD


SH-7123
6S 47E S29
DACC
SH-7124
6S47ES30
BCBB
SH-7128
6S 47E S36
ACAC
SH-7134
6S 48E S29
BBAA
Depth
sampled

90 to
96ft.
88 to
90ft.
174 to
178 ft.


192to
201 ft.

56 to
63ft.

112 to
122 ft.

54 to
64ft.
Lab. Coal Constituent, %
sample bed A12O3 CaO Fe203 K2O MgO Na2O P2OS SiO2 SO3 TiO2 Total

Canyon 10.9 31.6 7.4 .4 9.1 .9 .8 21.6 12.6 .7 96.0
376
Local 18.9 18.4 4.3 .5 4.7 6.1 1.5 27.2 14.0 2.2 97.8
377
12.5 12.2 11.9 .5 3.4 3.4 1.6 34.2 15.9 .9 96.5
378

Canyon 10.5 31.0 10.0 .2 7.4 9.7 1.1 10.8 14.1 .6 95.4

379
Canyon 10.3 36.3 8.8 .2 12.1 1.0 .4 9.9 14.9 .3 94.2

380
Canyon 11.1 33.2 7.8 .3 8.8 8.4 1.1 9.4 12.6 . .5 93.2

383
Canyon 10.1 26.9 8.9 .2 7.1 6.6 .7 19.3 18.7 .6 99.1

384

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-------
Table 60.-Proximate analysis, forms of sulfur, and heating value, Goodipeed Butte coal deport.
                                                                                                                                oo
                                         Proximate, %
form of sulfur, %
Drill hole
and location
SH-7126
6S 46E S28
BAB A
Drill hole
and location
SH-7126
6S 46E S28
BABA
Depth Lab.
sampled number
88 to
91 ft. 381
94 to
97 ft. 382
Depth Lab.
sampled sample
88 to
91 ft. 381
94 to
97 ft. 382
Coal Form of Volatile Fixed
bed analysis / Moisture matter carbon Ash Sulfur Sulfate Pyritic Organic
Cook A 33.290 25.291 32.550 8.869 2.054 .054 .840 1.159
B 37.913 48.793 13.294 3.079 .082 1.259 1.738
C 43.726 56.274 3.551 .094 1.453 2.004
A 33.710 23.071 30.776 12.443 1.220 .045 .475 .700
B 34.803 46.427 18.771 1.841 .068 .716 1.057
C 42.845 57.155 2.266 .084 .881 1.301
Table 6 1 .-Major ash constituents, Goodcpeed Butte coal deposit
Coal Constituent, %
bed A12O3 CaO FejOa
Cook 14.2 7.7 11.8
18.3 6.8 7.9
KjO MgO Na3O PaO» SiOj SO, TiOj Total
1.1 4.9 .4 .1 32.0 18.4 .5 91.1
1.2 2.8 .4 .6 46.8 9.2 .8 94.8
Heating
value (Btu)
6861
10285
11861
6682
10081
12410
STRIP? ABLE COAL. SOUTHEASTERN MONTANA

-------
                                             Table 62.-Ptoxiraate analysis, fomu of tulfur, tod heating value, Fire Gulch coal deposit.
                                                                                Proximate, %
                                                                                                   Form of sulfur, %
 Drillhole
and location
SH-7135
6S 48E S29
ABAC
Depth
sampled
115 to
125 ft.

125 to
133 ft.

137 to
142 ft.
 Lab
number
 385
                                 386
                                 387
Coal
bed
                       Cook
Form of
analysis1/
             A
             B
             C
             A
             B
             C
             A
             B
             C

Moisture
33.620


28.960


35.180
.

Volatile
matter
27.425
41.315
44.491
30.725
43.250
45.463
27.917
43.069
45.517
Fixed
carbon
34.217
51.547
55.509
36.857
51.882
54.537
33.417
51.554
54.483

Ash
4.738
7.138

3.458
4.868

3.485
5.377

Sulfur
.258
.389
.419
.384
.541
.569
.349
.538
.568
Sulfate
.022
.032
.035
.015
.022
.023
.014
.022
.023
Pyritic
.057
.087
.093
.061
.087
.091
.049
.075
.080
Organic
.179
.270
.291
.307
.433
.455
.286
.441
.466
                                                  Heating
                                                value (Btu)
                                                                                                   7530
                                                                                                  11343
                                                                                                  12215
                                                                                                   8198
                                                                                                  11540
                                                                                                  12131
                                                                                                   7491
                                                                                                  11556
                                                                                                  12213
 /A, as received; B, moisture free; C, moisture and ash free.
                                                            Table 63.-Major ash constituents, Fire Gukh coal deposit.
        Drillhole      Depth       Lab.         Coal
       and location    sampled     sample        bed
                                                                              Constituent, %
                                       AljO3  CaO     FejOj   KjO    MgO     NajO    PjOj    SK>a     SOj   TiOj    Total
       SH-7135
       6S 48E S29
       ADAC
  115 to
  133 ft.
                           Cook
   385-386
                             13.5    30.8
                                  5.2
                                       10.7
1.4
20.4
13.3    .5
96.7
                      137 to
                      142 ft.
              387
                                        10.2    32.4
                                               5.1
                                                  8.0
                                                5.7
                 15.1
         17.9
                                                                                                                            95.2

-------
100
STR1PPABLE COAL. SOUTHEASTERN MONTANA
Pawnee coal bed as shown on the Fire Gulch map (PI.
21) was included in the  report by Ayler, Smith, and
Deutman(1969).

                  LAND OWNERSHIP

   Except for approximately three-quarters of T. 6 S.,
R. 48 E., all the surface and the coal in the Diamond
Butte, Goodspeed Butte, and Fire Gulch area are owned
by the Federal Government and administered by the U.S.
Forest Service, Custer National Forest. The State of Mon-
tana owns the surface and coal in sec. 16 and 36 in T. 6 S.,
R. 48 E. The Federal Government also has a few isolated
40-acre tracts within this  township, which are adminis-
tered by the U.S. Bureau of Land Management. The rest
of the surface  in  this township is privately owned, but
very little if any land in the other townships is privately
owned.

          SURFACE FEATURES AND LAND USE

   The most prominent feature within the area is the high
grass-covered divide between Powder  River to the east
 and Otter Creek to the west. The barren tops of Diamond
 Butte, Goodspeed Butte, and other high points contrast
 sharply  with  the relatively flat ridges at lower levels,
 which  have been dissected by the steep tributaries  of
 Powder River and Otter Creek. These deeply incised val-
 leys are separated by long ridges extending both north-
 west and southeast from  the divide. These very steep
 sides of ridges are lined with lush growth of ponderosa
 pine  trees,  which are supported by clinker. The  ridges
 are accessible from  the top of the divide by  trails that
 extend from the divide to  the ends of the ridges. The val-
 leys have a very definite northwest lineation, especially
 on the Powder River side of the divide.

   The principal land use  in the area is livestock grazing,
 as ranchers in the vicinity  have grazing permits on Forest
 Service land.

                 GEOLOGIC STRUCTURE

    Strata in the Diamond Butte,  Goodspeed Butte, and
 Fire  Gulch  coal deposits dip generally southwest, except
 for local reversals. An anticlinal structure occurs  in the
 southwest corner of T. 6 S., R. 47 E.

                     COAL BEDS

    The coal beds of economic interest in the Diamond
 Butte, Goodspeed Butte, and Fire Gulch coal deposits
 are, from top to bottom, the Canyon, Cook, and Pawnee
 coal beds. Strippable reserves in the Canyon coal bed are
 shown in the Diamond  Butte area (PI. 19), strippable  re-
                        serves in the Cook bed are shown in the Goodspeed Butte
                        area  (PI. 20), and  strippable  reserves  in the Cook and
                        Pawnee  beds are shown in  the Fire Gulch coal deposit
                        (PI. 21). The Canyon  bed is  about  200 feet above the
                        Cook bed in the Diamond  Butte coal deposit (PI. 19),
                        sec. 30, T. 6 S., R. 47 E., as shown in drill hole SH-7124,
                        and in drill hole SH-7134, sec. 29, T. 6 S., R. 48 E.

                           The Cook coal bed consists of two benches throughout
                        the area. In drill hole SH-7124 the upper bench is 14 feet
                        thick, the  lower bench is 12  feet thick, and the parting is
                        34 feet.  In SH-7134, however, the upper bench is 22 feet
                        thick, the  lower bench is 14 feet thick, and the parting is
                        only 3 feet thick.  Thicknesses measured in SH-7135 in
                        sec. 29, T.  6 S., R.48 E., are very similar to these. In drill
                        hole SH-7121, in sec.  16, T. 6 S., R. 48 E., the Canyon
                        bed is 211  feet above the Cook bed, and the upper bench
                        of the Cook bed is 22 feet thick, the lower bench 12 feet,
                        and the parting 12 feet. The parting between the two
                        benches of the Cook seems to increase locally (PI. 20) as
                        shown in drill hole SH-7131,  sec. 6, T. 6S..R.47 E. In
                        this drill hole, the upper bench, 13 feet thick, and the
                        lower bench,  12 feet thick,  are separated by a parting of
                        45 feet. In drill hole SH-7133 of the same township, the
                        upper bench, 20 feet thick, and the lower bench, 14 feet
                        thick, are separated by a 34-foot parting.

                           In the  Diamond Butte coal deposit, thickness of the
                        Canyon  bed ranges from 7 feet in the northern part, as
                        measured in drill hole SH-7130 in sec. 15,T. 6S., R.47 E.,
                        and drill hole SH-7121  in sec.  16, T. 6 S., R. 48 E., to 16
                        feet in drill hole SH-7122 in sec.34, T. 6 S., R.47 E. The
                        Canyon  bed is easily recognizable because a coal bed 2 to
                        4 feet thick lies about 15 feet above it. This marker bed
                        is noted in the mechanical logs of all the drill holes in the
                        Diamond Butte coal deposit.  The thin coal bed corres-
                        ponds with a similar bed above the Canyon in  the West
                        Moorhead coal deposit farther  south (Matson, 1970, p. 6).

                           The Pawnee coal bed and its clinker crop out at num-
                        erous localities in T. 6 S., R.  49 E. (PI. 21). A thickness
                        of about 20 feet was measured in sec. 5 and also in sec. 25
                        (Warren, 1959). Strippable  reserves in  the Pawnee coal
                        bed have previously been outlined along Pinto Creek and
                        Fire Gulch in sec. 36,  T. 6 S., R. 48 E., and sec. 19, 20,
                        30, and  31, T.6 S., R.49 E. (Ayler, Smith, and Deutman,
                        1969). Other strippable reserves of the Pawnee have been
                        outlined along Cache Creek in  sec. 1,T. 6 S..R.48 E., and
                        sec. 6 and  7, T. 6 S., R. 49 E. (Matson, Dahl, and Blumer,
                        1968).

                                            COAL QUALITY

                           Twelve core samples were obtained during the current
                        project  and  were analyzed  by the Montana Bureau of

-------
                           INDIVIDUAL DEPOSITS—SWEENEY CREEK-SNYDER CREEK
                                                                                                       101
Mines and Geology analytical laboratory. Proximate an-
alysis, forms of sulfur, and heating value for the Diamond
Butte coal deposit are shown in Table 58, for Goodspeed
Butte in Table 60, and for Fire Gulch in Table 62. An-
alytical results of composite samples showing ash constit-
uents are shown in Tables 59, 61, and 63.

   Although no  cores were obtained  from the Pawnee
coal bed in the Fire Gulch coal deposit on this project, a
core taken previously was reported by Matson, Dahl, and
Blumer (1968). This core sample was obtained in sec. 36,
T. 5 S., R. 48 E., and on the "as received" basis, shows a
moisture content of 32.0%, volatile matter 29.5%, fixed
carbon 32.5%, ash 6%, sulfur 0.2%, hydrogen 6.7%, car-
bon 45.4%, nitrogen 0.8%, oxygen 40.9%, heating value
7,650 Btu.

                  COAL RESERVES

   The Goodspeed Butte coal deposit has reserves in the
Cook coal bed totaling 628,950,000 tons, the Diamond
Butte coal deposit has  reserves in the Canyon coal bed
totaling 418,020,000 tons, and the Fire Gulch coal de-
posit has reserves of 336,690,000 tons in the Cook and
Pawnee coal beds (Table 57).

 SWEENEY CREEK-SNYDER CREEK COAL DEPOSIT

                     LOCATION

   The Sweeney Creek-Snyder Creek coal deposit (PI. 22)
is in T. 2 and 3 N., R.43 and 44 E., Rosebud County. The
deposit is on the divide between Rosebud Creek on the
west and Tongue River on the east, and is about 20 miles
south of the Yellowstone River.

         FIELD WORK AND MAP PREPARATION

   The field work in the Sweeney  Creek-Snyder Creek
area was completed in the summer of 1968 under a co-
operative agreement  between the Montana Bureau of
                                      Mines and Geology  and Burlington Northern, Inc. The
                                      purpose was to gain new information on the quality and
                                      quantity of coal resources  in  strippable coal fields in
                                      southeastern Montana. The Bureau and the railroad each
                                      provided part of the evaluation cost.

                                        The field work was conducted under the supervision
                                      of Loren Williams assisted by Peter Mattson of Burlington
                                      Northern, Inc., and Gardar G. Dahl, Montana Bureau of
                                      Mines and Geology. The field method utilized  was devel-
                                      oped by Burlington Northern, Inc. (Carmichael, 1967).

                                                  PREVIOUS GEOLOGIC WORK

                                        The geology of the Sweeney Creek-Snyder Creek coal
                                      deposit was described in a US. Geological Survey report
                                      on the Rosebud coal field (Pierce, 1936). The  strippable
                                      coal  was also outlined and discussed in the  report by
                                      Ayler, Smith, and Deutman (1969).

                                                       LAND OWNERSHIP

                                        The Sweeney  Creek-Snyder Creek coal  deposit lies
                                      within  the land grant to Burlington Northern, Inc. The
                                      railroad has retained ownership of mineral rights in the
                                      odd-numbered sections but has conveyed the surface. The
                                      Federal Government retained the coal rights when it con-
                                      veyed the even-numbered sections. The State of Montana
                                      owns the surface and minerals in sec. 16 and 36 of each
                                      township.

                                               SURFACE FEATURES AND LAND USE

                                        The divide between Tongue River and Rosebud Creek
                                      has a fairly flat top and is bordered by clinker formed by
                                      burning of the Terret coal bed. The rugged slopes of the
                                      sharp and deep valleys  on  both sides  of the  divide are
                                      covered  with ponderosa pine. The principal land use  in
                                      the area is livestock grazing.
         Table 64.-Reserves, overburden, overburden ratio, acres, and tons/acre, Sweeney Creek-Snyder Creek coal deposit.
                                                TtRRET BED
   Thickness of
  overburden, ft.
Indicated reserves,
  million tons
 Overburden,
million cu. yd.
Overburden ratio,
 cubic yards/ton
Acres
Tons/acre
      Oto 50
     50 to 100
    100 to 150
              Total
                  Total
                       1.77
                       4.08
                       7.17
               Average  2.97
              Total
                  30,162.4
                  29,686.8
                  28.106.8
          Average  29,880.4

-------
Table 65.-Proximite analysis, ultimate analysis, loimt of sulfur, and heating value,
                  Sweeney Creek-Snyder Creek coal deposit.
s
Proximate, %
Drillhole
and location
SS-IC
2N44I S29
CABC
SS-2C
2N 441-. S4
CAD A
SS-3C
3N44I- S27
CCBB
SS-5C
.IN 441 S3
IMA A


I
/A, as received





Depth
sampled

50 to
66 ft

74 to
92ft

80 to
97ttft

109 to
127 ft



; B. moisture





Lah and
sample no.
J-11591

GF -69-36
J 11592

GF-69-37
J-11593

Gl -69-38
J-11594

GF-69-39



Coal
bed
Terret


Terret


Terret


Terret





free; C. moisture and ash










Form of .
analysis /
A
B
C
A
B
C
A
B
C
A
B
C



free.

Table 66



Volatile
Moisture matter
2391 27.91
33.68
41.69
24.63 27.79
36.87
41.96
24.53 28.28
37.47
42.72
25.31 28.27
37.86
43.33





Fixed
carbon Ash
39.03 9.15
51.30 12.02
58.31
38.44 9.14
51.00 12.13
58.04
37.92 9.27
50.25 12.28
57.28
36.99 9.43
49.52 12.62
56.67





Ultima te,%
Heating
S H C N O value (Btu) Sulfur
1.53 5.77 49.62 .81 33.12 8310 1.53
2.01 4.08 65.22 1.07 15.60 10930 2.01
2.29 4.64 74.13 1 22 17.72 12420 2.29
1.12 5.82 48.95 .82 34.15 8200 1.12
1 49 4.10 64.95 1.08 16.25 10870 1.49
1 69 4.67 73.92 1.23 18.49 12370 1.69
.94 5.78 49.04 .81 34.16 8170 .94
1.24 4.06 64.97 1.07 16.38 10830 1.24
1.42 4.62 74.07 1.22 18.67 12350 1.42
1.18 5.87 48.45 .80 34.27 8020 1.18
1.59 4.09 64.87 1.07 15.76 10740 1.59
1.82 4.68 74.24 1.23 18.03 12290 1.82





Form of sulfur. %




Sulfate Pyritic Organic
.07
.09
.10
.08
.10
.11
.03
.04
.05
.05
.07
.08





1.13
1.48
1.69
.77
1.02
1.16
.58
.77
.88
.92
1.23
1.41





.34
.44
.50
.28
.37
.42
.33
.43
.49
.21
.29
.33





.-Major ash constituents and fusibility of ash, Sweeney Creek-Snyder Creek coal deposit.


















Fusibility of ash. °F

Drill hole
and location
SS-IC
2N44F S29
CABC
SS-2C
2N 441: S4
CADA
SS-3C
3N 44E S27
CCBB
SS-5C
3N 44E S3
DAAA

Depth
sampled

50 to
66ft.

74 to
92ft.

80 to
9TA ft.

109 to
127 ft.

Lab.
sample


GF-69-36


GF-69-37


GF-«9-38


GF-69-39

Coal
bed
Terret


Terret


Tcrret


Terret




A.,03
154


16.2


13.8


13.7




CaO Fe2O3 KjO
13.0 19.0 .2


13.3 13.8 3


16.9 12.8 .3


16.6 14.4 .2


Constituent,

MgO NajO
3.2 1.3


4.1 2.7


4.1 1.7


5.5 .4


% Initial

• 	 deformation
P2O5 SiC-2 SO3 TiOj Total temp.
.9 26.7 17.4 .8 97.9 1910


.4 30.5 16.2 .4 97.9 1900


.3 27.2 21.5 .4 99.0 1930


.3 27.0 21.4 .5 100.0 1940



Softening
temp.
1940


1940


1970


1970



Fluid
temp.
1970


1980


2010


2000


Real
specific
gravity
1.59


1.58


1.56


1.59








CO
H
2
1
to
5
O
O
r
CO
O
n
co
H
n
V
z
s
O

-------
                                      INDIVIDUAL DEPOSITS—YAGER BUTTE
                                                                                                            103
                GEOLOGIC STRUCTURE

    The strata in the Sweeney Creek-Snyder Creek coal
 deposit, although nearly horizontal, show a gentle south-
 erly dip.

    A fault, mapped in sec. 1, T. 3 N., R. 44 E., has a strike
 of N. 30° W. and a maximum throw of 60 feet. The south-
 west side of the fault is downdropped (Pierce, 1936, pi. 1).

                      COAL BEDS

    The Terret coal bed is the only one that contains strip-
 pable reserves in  the  Sweeney Creek-Snyder Creek coal
 deposit. The Burley bed, below the Terret bed, is gener-
 ally thin  throughout the area (Pierce, 1936), and it is 4
                                           feet thick in drill hole SS-1C in sec. 29, T. 2 N., R. 44 E.
                                           The Terret coal bed, 17 to 18 feet thick throughout the
                                           area, has burned along the sides of the ridge.

                                                              COAL QUALITY

                                              Four core samples of the Terret coal bed were ob-
                                           tained and analyzed by the US. Bureau of Mines Coal
                                           Research Laboratory at Grand Forks. Proximate analysis,
                                           ultimate analysis, heating value, and forms of sulfur are
                                           shown in Table 65. Major ash constituents, fusibility of
                                           ash, and specific gravity are shown in Table 66.

                                                              COAL RESERVES

                                              Reserves in  the  Terret coal bed total 326,330,000
                                           tons (Table 64).
               Table 67.-Reserves, overburden, overburden ratio, acres, and tons/acre, Yager Butte coal deposit.
                                           ELK and DUNNING BEDS
 Thickness of
overburden, ft.
Indicated reserves,
   million tons
   Overburden and
    interburden,
    million cu. yd.
               Overburden and
               interburden ratio,
                cubic yards/ton
                         .Acres
                           Tons/acre
    Oto 50
   50 to 100
  100 to 150
             Total
     442.35
     417.60
     315.91
    1,175.86
Total
 836.6
1,567.35
1.361.27
3,765.22.
        1.89
        3.75
        4.30
Average  3.20
Total
11,116.4
 9,689.2
 6.118.4
26,924.0
        39,793.9
        43,100.4
        51.632.8
Average  43,673.3
                                                 COOK BED
 Thickness of
overburden, ft.
Indicated reserves,
   million tons
     Overburden,
    million cu. yd.
               Overburden ratio,
                cubic yards/ton
                         Acres
                           Tons/acre
    Oto  50
   50 to 100
  100 to 150
             Total
                           156.71
                           688.75
                         1.182.31
                   Total  2,027.77
                            2.95             2,943.4
                            6.11             5,692.0
                            8.09             5.872.1
                   Average  6.50     Total   14,507.5
                                                         18,070.94
                                                         19,803.23
                                                         24.882.07
                                                Average  21,507.50
           YAGER BUTTE COAL DEPOSIT

                       LOCATION

    The Yager Butte coal deposit (PI. 23 A and B) is in T. 3,
 4, and 5 S., R. 46 and 47 E., Powder River County. The
 area  is bordered  on the south by the Diamond Butte
 (PI. 19), the Goodspeed Butte (PI. 20), and the  Fire Gulch
 (PI. 21) coal fields. The area is overlapped on the east by
 the Threemile Buttes (PI. 24) and by the Sonnette (PI.
                                           25A and B) coal fields. On the north it adjoins the Ash-
                                           land coal field (PI. 13) and on the west  the Otter Creek
                                           coal field (PI. 12). The area is on the west side of the high
                                           divide between Pumpkin  Creek to  the east  and Otter
                                           Creek to the  west.

                                                   FIELD METHODS AND MAP PREPARATION

                                              Field work in the Yager Butte area, done in 1970 and
                                           1971, included drilling numerous exploration holes and

-------
                                            Table 68.-Proximate analysis, forms of sulfur, and heating value, Yager Butte coal deposit.
  Drill hole
 and location
 SH-7047
 5S R47E S29
 CAAA
 SH-7048
 5S R46L S25
 CDDC
 SH-7050
 5S R47E S4
 AADD

 SH-7137
 5S R47E S22
 ADCC
SH-7144
5SR46ES15
BDCA
SH-7145
4S R46E S19
DDAA
  Depth
 sampled
 141 to
 151 ft.

 151 to
 156 ft

 156 to
 158 ft.
 62 to
 72ft.

 72 to
 76 ft.
 86 to
 94ft.
 50 to
 60ft.

115 to
118ft
 92 to
 98ft.

 98 to
102ft
 38 to
 43ft
  Lab.
number
 240


 241


 242



 243


 244



 249



 388


 389



 395


 396



397
Coal
bed
                       Cook
                                                                               Proximate.
                                                                                                 Form of 






-------
SH-7145
4SR46ES19
DDAA

SH-7146
4S R46E S20
CABC
SH-7148
4S R46E S23
DBCB

SH-7149
4SR46ES14
CADC
SH-7150
4S R47E S7
CBBD
 43 to
 48ft.
 30 to
 35ft.

 35 to
 40ft.

100 to
106 ft.

106 to
110ft.
 51 to
 54ft.
 43 to
 52ft.

 52 to
 54ft.
 31 to
 33ft.

 33 to
 41 ft.
398



399


400


401


402



403



404


405



406


407
                      Elk
                      Elk
                                          Dunning
                      Local
                       Dunning
                       Elk
A
B
C

A
B
C
A
B
C
A
B
C
A
B
C

A
B
C

A
B
C
A
B
C

A
B
C
A
B
C
30.610


31.120


30.880


30.060


30.170


32.260


28.590


33.810


33.760


33.170


27.907
40.218
45.076
27.753
40.291
44.455
29.031
42.000
44.905
29.067
41.560
45.325
29.219
41.844
44.627
28.593
42.210
45.335
30.188
42.274
45.369
28.190
42.589
45.771
28.172
42.531
46.039
28.568
42.747
46.279
34.004
49.005
54.924
34.676
50.343
55.545
35.618
51.531
55.095
35.064
50.134
54.675
36.255
51.919
55.373
34.478
50.898
54.665
36.350
50.904
54.631
33.398
50.459
54.229
33.020
49.850
53.961
33.162
49.621
53.721
7.478
10.777

6.452
9.366

4.471
6.468

5.809
8.306

4.356
6.238

4.669
6.892

4.872
6.823

4.602
6.952

5.047
7.620

5.100
7.632

.535
.771
.864
.435
.632
.697
.222
.321
.343
.225
.322
.351
.210
.300
.320
.760
1.122
1.205
.229
.321
.344
.395
.597
.642
.284
.429
.465
.250
.374
.404
.037
.054
.060
.044
.064
.071
.022
.032
.034
.015
.021
.023
.015
.021
.023
.043
.064
.069
.000
.000
.000
.014
.021
.023
.021
.032
.035
.029
.043
.046
.119
.171
.192

.096
.139
.154
.015
.021
.023
.000
.000
.000
.000
.000
.000

.123
.182
.195

.053
.075
.080
.120
.181
.195

.028
.043
.046
.036
.053
.058
.379
.546
.612

.295
.428
.472
.185
.268
.286
.210
.300
.327
.195
.279
.297

.594
.876
.941

.176
.246
.264
.261
.395
.424

.235
.354
.383
.185
.278
.300
7575
10916
12235
7515
10910
12037
7943
11492
12286
7817
11177
12189
7991
11444
12205

7722
11400
12244
8005
11209
12030
7445
11248
12088
7297
11016
11925
7371
11030
11941






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 /A, as received; B, moisture free; C, moisture and ash free.

-------
Table 69,-Major ash constituents, Yager Butte coal deposit.
Drill hole
and location
SH-7047
5S47L S29
CAAA
SH-7048
5S 461: S25
CDDC
SH-7050
5S47tS4
AADD

SH-7137
5S47ES22
ADCC




SH-7I44
5S46ES15
BDCA

SH-7145
4S46ES19
DDAA

SH-7146
4S 46E S20
CABC


SH-7148
4S 46E S23
DBCB
SH-7149
4S46ES14
CADC
SH-7150
4S 47E S7
CBBD
Depth
sampled

141 to
158 ft.

62 to
76 ft

86 to
94 ft.


50 to
60ft.

115to
118ft.


92 to
102 ft


38 to
48ft.


30 to
40ft
100 to
1 10 ft.

51 to
54ft.

43 to
54ft.

31 to
41 ft.
Lab. Coal
sample bed
Cook

240-242
Cook

243-244
Elk

249

Cook

388


389

Elk

395-396

Elk

397-398

Elk

399-400
Dunning
401-402
Local

403
Dunning

404-405
Elk

406407

A1203
18.2


13.3


12.5



8.0



11.1


10.6



13.1



12.7


18.4

13.4


18.0


15.2



CaO
7.8


22.3


33.9



32.6



28.1


24.9



17.8



19.9


19.2

15.7


23.6


20.1



Fe203
9.3


8.7


6.2



5.3



9.3


6.3



5.5



5.1


4.7

8.8


4.4


4.8



K2O
2.9


.2


.2



.1



.2


.1



.8



.7


.2

.5


.2


.2


Constiti
MgO
4.0


6.7


8.5



9.9



6.4


13.2



4.7



6.6


6.5

9.1


6.6


9.9


tent, TO
Na2O
.4


2.9


2.9



.6



6.2


.7



8.7



4.5


4.6

2.0


4.6


1.3



P205
.2


.4


3.1



.2



1.1


.7



.4



.4


.6

.1


.2


.4



Si02
45.9


23.6


9.6



19.7

••

9.9


21.7



31.2



35.4


31.6

21.5


25.6


33.7



S03
10.6


19.1


17.3



14.8



23.7


15.1



13.7



8.8


9.0

21.7


8.9


9.5



TiO2
.5


.5


.4



.4



.3


.6



.6



.8


1.1

5


.9


1.2



Total
99.8


97.7


94.6



91.6



96.3


93.9



96.5



94.9


95.9

93.3


93.0


96.3










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-------
                             INDIVIDUAL DEPOSITS—SONNETTE, THREEMILE BUTTES
                                                                                                        107
mapping the surface on black-and-white aerial photos or
on 7^-minute topographic quadrangle maps. Color photos
of the Custer National Forest obtained from the U.S.
Forest Service were used to complete the mapping of coal
outcrop and burn lines.

             PREVIOUS GEOLOGIC WORK

   The Yager Butte coal deposit is included in the report
on the Birney-Broadus coal field (Warren, 1959).

                  LAND OWNERSHIP

   Most  of the Yager Butte coal deposit is within the
boundaries of the  Custer National  Forest, which is ad-
ministered by the U.S. Forest Service, but a small portion
in T. 5 S., R. 47 E., lies outside the forest boundary. The
Federal  Government has  retained ownership of all the
coal, however.

         SURFACE FEATURES AND LAND USE

   The surface features in the Yager Butte coal deposit
consist of a broad rolling  upland  area that forms the di-
vide between Pumpkin Creek to the east and Otter Creek
to the west and breaks into precipitous slopes along the
valleys of Elk Creek, Fifteenmile  Creek, Tenmile Creek,
and Threemile Creek. The burning of coal beds in the
area has created thick masses of multicolored clinker that
form  resistant capping along the  ridge sides. The ridges
between  the tributaries of Otter Creek are relatively flat
and grass covered, and the sides support lush growths of
ponderosa pine and other vegetation.  These  tributaries
contain water in pools the year round but they flow only
during periods of heavy precipitation or spring runoff.

   The principal land use  in the area is livestock grazing.
Many nearby ranchers have grazing permits in the Na-
tional Forest.

               GEOLOGIC STRUCTURE

   The strata in the Yager Butte coal deposit seem to be
nearly horizontal but show a very slight southwesterly dip.

                     CQAL BEDS

   Coal beds in the Yager Butte coal deposit that contain
economically strippable reserves are, from top to bottom,
the Cook, Elk, and Dunning beds. Strippable reserves in
the Elk and Dunning coal beds are shown on Plate 23A
and those in the Cook bed on Plate 23 B. The Wall coal
bed has been identified in the northern part of the area
(PI. 34).
   The Cook coal bed in the Yager Butte coal deposit is
in two benches 30 to 66 feet apart. In drill hole SH-7136,
sec. 33, T. 5 S., R. 47 E., the upper bench of the Cook is
19 feet thick, the lower bed is 11 feet thick, and the two
benches are 30 feet apart. In that same drill hole, a higher
coal bed 6 feet thick is identified as the Canyon coal bed.
To the north and northwest, the Cook beds thin. In drill
hole SH-7138, sec. 17, T. 5 S., R. 47 E., the Upper bench
is 6 feet thick, the lower bench is 9 feet, and the parting
is 66 feet. In drill hole SH-7139, sec. 15 of the same town-
ship, the upper bench of the Cook is 5 feet thick, the
lower bench  is 8 feet, and the parting is 30  feet. The
upper bench of the Cook is missing farther north.

   The Wall coal bed, 11 feet thick, is 72 to 130 feet be-
low the Cook bed in the mapped area. The Elk and  Dun-
ning coal beds, shown on Plate 23A, have large reserves
within the mapped area. The Elk bed is 23 feet above the
Dunning bed in drill hole SH-7144, sec. 15, T. 5 S., R. 46 E.,
and 39 feet above it in an oil well  in  sec. 28, T.  4 S.,
R. 47 E. The Elk bed is 10 feet thick in an oil well in
sec. 28 (cross section, PI. 34) and is 21 feet thick in drill
hole SH-7145 in sec. 19, T. 4 S., R. 46 E. Thickness of
the Dunning  bed ranges from 14 feet in drill holes SH-
7145 and SH-7146 to 20 feet in the oil well in sec. 28.

                   COAL QUALITY

   Twenty-one core  samples were obtained during the
field evaluation and were analyzed by the Montana Bu-
reau of Mines and Geology analytical laboratory. Proxi-
mate analysis, forms of sulfur, and heating values are
shown in Table 68, and major ash constituents are shown
in Table 69.

                  COAL RESERVES

   The indicated coal reserves  in the Elk and Dunning
coal beds are 1,175,860,000 tons, and in the Cook bed
they are 312,020,000 tons. Total reserves in the Yager
Butte coal deposit are 1,487,880,000 tons (Table 67).

      SONNETTE AND THREEMILE BUTTES
                 COAL DEPOSITS

                    LOCATION

   The Sonnette  area is in T. 3,4,5, and 6 S., R. 47,48,
and 49 E., Powder River County. The maps outlining the
strippable coal in the Sonnette area include the Threemile
Buttes (PI. 24) and the Sonnette (PI. 25A and B) coal de-
posits, which  are discussed together because of the  large
amount of overlap in the  two deposits. The area is joined
on the north by the Pumpkin Creek coal deposit (PI. 15),

-------
108
STRIP?ABLE COAL, SOUTHEASTERN MONTANA
on the northwest it borders the Home Creek Butte coal
deposit (PI. 26), and on the south it borders the Diamond
Butte (PI. 19), Goodspeed Butte (PI. 20), and Fire Gulch
(Pi. 21) coal deposits. In the northwest corner of T. 4 S.,
R. 47 E., the area borders the Ashland coal deposit (PI.
ISA and B).

          FIELD WORK AND MAP PREPARATION

   Reconnaissance field  work in the area  in  1967 in-
cluded the drilling of one hole in sec. 16, T. 5 S., R.48 E.
Additional holes were drilled during the 1971 field season
to explore the Cook, Canyon, and Ferry coal beds, and
part of the area  was mapped on black-and-white aerial
photos. During the winter of 1972, the mapping was re-
fined by use of colored aerial photos borrowed from the
U.S. Forest Service. Field data were plotted on US. Geo-
logical Survey 7&-minute topographic quadrangle maps.

              PREVIOUS GEOLOGIC WORK

   The Sonnette area was included in the US. Geological
Survey report on the Birney-Broadus coal field (Warren,
 1959). Strippable coal in the Pawnee bed was outlined in
 Montana Bureau  of Mines and Geology  Bulletin 69 (Mat-
 son, Dahl, and Blumer, 1968).

                   LAND OWNERSHIP

   The Sonnette  area borders the Custer National Forest,
 and the Threemile Buttes coal deposit (PI. 24) overlaps
 onto the forest. East of  the forest boundary, the owner-
 ship is mixed; the State of Montana owns sec. 16 and 36
 in each township, and the rest of the surface is privately
 owned. The area is within the land grant to Burlington
 Northern, Inc., and in T. 4 S., R. 48 E., and the eastern part
 of T. 4 S., R. 47 E., the railroad owns the  coal in odd-
 numbered sections, but  T. 5 S. is south of the railroad
 land grant, and most of the coal there is federally owned.

          SURFACE FEATURES AND LAND USE

    The most prominent surface feature in the Sonnette
 area is  the Pumpkin Creek valley.  Near Sonnette the
 creek turns abruptly from east to north and flows north-
 ward  to join the Tongue River in T. 6 N., R. 48 E. The
 burning of the Cook coal bed has formed resistant clinker
 that supports  flat-topped benches and ridges and steep
 valley sides.

    The valley  sides are  covered by ponderosa  pine, but
 the ridgetops are barren except for native grasses. Pump-
 kin Creek is an  intermittent stream, which flows only
 during periods of heavy precipitation or spring  runoff,
 although ponds persist throughout the year. The valley is
                        Vi to 1 mile wide throughout  most of its length in the
                        area. Most of its tributaries are short and steep except in
                        the  southern  part of the area. Numerous roads traverse
                        the  eastern and southern part of the area. Sonnette Post
                        Office is in sec. 8, T. 5 S., R. 48 E.

                          Although the principal land use in the area is livestock
                        grazing, numerous fields are cultivated along the bottom
                        of Pumpkin Creek valley. In other parts of the area where
                        topographic conditions permit, winter wheat and other
                        grains  are  raised  on  summer  fallowed  tracts. Grazing
                        permits on the National Forest are allotted to nearby
                        ranchers.

                                       GEOLOGIC STRUCTURE

                          All  the streams within the Sonnette area seem to be
                        structurally controlled. The most prominent streams and
                        ridge lines show definite  northwest-southeast trends.

                          Drill data of the Pawnee coal bed show that the strata
                        dip  gently to  the southwest but reversals are numerous.
                        A structural depression in sec. 7,8, and 17, T. 4 S., R. 48 E.,
                        trends  northwest. A structurally high area is mapped in
                        the  northeast  corner of T. 5 S., R. 48 E.

                                             COAL BEDS

                          Coal beds of economic importance in the Sonnette
                        area include,  from lowest to highest, the Pawnee, Cook,
                        Ferry, and Canyon beds, all of which have adequate thick-
                        ness and quality for economical stripping. The Pawnee
                        coal bed crops out along the sides of the Pumpkin Creek
                        valley in the western half of T. 4 S., R. 48 E., but passes
                        beneath alluvium in sec. 33. The greatest thickness of the
                        Pawnee is 22  feet, measured in drill hole SS-4, sec.  16,
                        T. 5 S., R. 48 E. In drill hole SH-7114, sec. 20, T. 4 S.,
                        R. 48  E., a 2-foot parting splits the bed into an upper
                        bench  12 feet thick and a lower bench 10 feet thick. To
                        the east and south, the Pawnee bed  maintains a thickness
                        of 20 feet as  far as the Fire  Gulch coal deposit (PI. 21)
                        as it is  that thick in drill hole SS-3, sec. 36, T. 5 S., R. 48 E.
                        Inferred reserves in the Pawnee coal bed are shown on the
                        east side of the mapped area, which is beyond the area
                        shown on adequate topographic maps. These reserves ex-
                        tend south into Cache Creek in the northwest corner of
                        T. 6 S.,  R. 49 E. Indicated  reserves in the Pawnee coal
                        bed are mapped along the sides and bottom of Pumpkin
                        Creek valley and back of the outcrop along the east side
                        of the divide extending to sec. 36, T. 4 S., R. 48 E.

                           Strippable  reserves in the Cook coal bed (PI.  25B),
                        which  lies about 170  to 200 feet above the Pawnee bed,
                        cover a  large area in the  vicinity  of Sonnette. Clinker

-------
                          INDIVIDUAL DEPOSITS—SONNETTE, THREEMILE BUTTES
                                                                                                  109
       Table 70.-Reserves, overburden, overburden ratio, acres, and tons/acre, Sonnette and Threemile Buttes coal deposits.
                                                      COOK BED
 Thickness of
overburden, ft.
    Indicated reserves,
       million tons
Overburden and
  interburden,
 million cu. yd.
    Overburden and
   interburden ratio,
    cubic yards/ton
          Acres
                      Tons/acre
Oto 50
50 to 100
100 to 150
150 to 200
Total
84.23
125.73
100.09
52.93
362.98
                                      Total
                                  228.88
                                  591.60
                                  616.40
                                  399.15
                                1,836.03
                           2.72
                           4.71
                           6.16
                           7.54
                  Average  5.06
                  Total
          3,027.2
          3,795.2
          2,464.0
          1.184.0
         10,470.4
              Average
          27,826.2
          33,130.4
          40,620.9
          44.704.4
          34,668.6
                                                     PAWNEE BED
    Oto  50
   50 to 100
  100 to 150
              Total
           92.46                  126.41               1.36
          125.11                  388.75               3.10
          102.68                  531.58               5.17
          320.25         Total   1,046.74      Average  3.26
                                    Total
                            2,374.4               38,940.4
                            3,212.8               38,941.1
                            2.636.8               38.941.1
                            8,224.0      Average  38,940.9
 Thickness of       Inferred reserves,         Overburden,
overburden, ft.        million tons           million cu. yd.
                                                Overburden ratio,
                                                 cubic yards/ton
                                             Acres
                                                Tons/acre
  100 to 150
          183.06
  ' 1,042.74
         5.69
         5,171
                       35,401.3
 Thickness of
overburden, ft.
      Total reserves,
       million tons
  Overburden,
 million cu. yd.
   Overburden ratio,
    cubic yards/ton
          Acres
                      Tons/acre
    Oto 50
   50 to 100
  100 to 150
              Total
                        Total
      126.41
      388.75
    1,574.28
    2,089.44
                  Total
         2,374.4
         3.212.8
         7.807.8
        13,395.0
                      38,940.4
                      38,941.1
                      36.596.7
             Average  37,574.5
                                               CANYON and FERRY BEDS
 Thickness of
overburden, ft.
    Indicated reserves,
       million tons
 Overburden,
million cu. yd.
   Overburden ratio,
   cubic yards/ton
          Acres
                      Tons/acre
    Oto  50
   50 to 100
  100 to 150
         107.99
          96.48
          20.93
Total    225.40
                                      Total
     360.43
     733.87
     204.12
    1,298.42
         3.33
         7.60
         9.75
Average  5.76
Total
 6,764.8
 6,060.8
 1,011.2
13,836.8
         15,963.5
         15,918.7
         20.698.2
Average  16,289.7

-------
                                               Table 71 .-Proximate analysis, forms of sulfur, and heating value, Sonnette coal deposit.
  Drill hole
 and location
 SH-7114
 4S 481 S20
 A BAB
 SH-711S
 4S 481-; S34
 DABD
 SH-7116
 4S 48F S29
 CCAD
SH-7117
5S48ES7
BCAA
SH-7118
5S 48E S22
DCDA
SH-7120
4S 48E S36
CCCC
 Depth
 sampled
  70 to
  80ft.

  80 to
  90ft.

  90 to
  95 ft.
 40 to
 50ft.

 50 to
 56ft
 30 to
 37ft.

190to
192 ft.
 72 to
 82 fi.

114 to
119ft
 38 to
 41 ft.

 78 to
 86ft.
 70 to
 72ft.
 Lab
number
 362


 363


 364



 365


 366



 367


 372



 368


 369



370


371



375
Coal
bed
                       Pawnee
                                                                                 Proximate. %
                                                                                                    Form of sulfur. %
                       Pawnee
                       Pawnee
                       Cook
                      Canyon
                      Cook

                      Cook
Torm of
analysis
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
*
/ Moisture
34.410


33.120


36.240


36.280


31.970


36.370


28.980


35.000


34.380


36.960


38.680


33.740


Volatile
matter
26.826
40.899
43.855
24.964
37.326
46.005
25.653
40.234
44.491
26.568
41.695
44.396
27.555
40.505
47.226
26.361
41.429
46.489
23.128
32.565
50.603
25.786
39.671
44.079
26.656
40.621
47.051
26.709
42.369
47.054
25.665
41.855
46.015
26.688
40.278
50.439
Fixed
carbon
34.343
52.360
56.145
29.299
43.809
53.995
32.007
50,199
55.509
33.275
52.220
55.604
30.793
45.264
52.774
30.343
47.687
53.511
22.577
31.789
49.397
32.714
50.329
55.921
29.997
45.714
52.949
30.054
47.674
52.946
30.111
49.105
53.985
26.224
39.577
49.561

Ash
4.421
6.741

12.617
18.865

6.099
9.566

3.877
6.085

9.682
14.231

6.925
10.884

25.315
35.645

6.500
10.000

8.967
13.665

6.277
9.957

5.544
9.041

13.348
20.145


Sulfur
.149
.227
.243
1.042
1.558
1.921
.306
.481
.532
.191
.300
.319
.368
.542
.631
1.400
2.200
2.469
2.731
3.845
5.975
.736
1.133
1.259
1.655
2.523
2.922
.955
1.516
1.683
.842
1.374
1.510
1.995
3.010
3.770

Sulfatc
.016
.024
.026
.016
.024
.029
.007
.012
.013
.023
.036
.038
.337
.496 •
.578
.030
.047
.053
.024
.033
.052
.024
.037
.041
.031
.047
.054
.022
.035
.039
.023
.037
.040
.037
.057
.071

Pyritic
.000
.000
.000
.286
.428
.528
.022
.035
.039
.023
.036
.038
.024
.035
.040
.640
1.006
1.128
1.432
2.017
3.134
.190
.292
.325
.659
1.004
1.163
.235
.373
.414
.181
.294
.324
.967
1.460
1.828

Organic
.133
.203
.218
.740
1.106
1.363
.277
.434
.480
.145
.228
.243
.008
.012
.013
.730
1.148
1.288
1.275
1.795
2.789
.523
.804
.893
.966
1.472
1.705
.698
1.108
1.230
.639
1.043
1.146
.990
1.494
1.871
Heating
value (Btu)
7364
11227
12039
6624
9904
12206
6936
10878
12029

7228
11343
12078
7138
10492
12233
7902
12418
13935
5556
7824
12157
7186
11055
12283
7000
10668
12357

6904
10951
12162
6818
11119
12224
6547
9881
12374










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 /A, as received; B, moisture free; C, moisture and ash free.

-------
             Table 72.-Major ash constituents, Sonnette coal deposit.
Coal
Constituent,
and location
SH-7114
4S 48E S20
ABAB


SH-7115
4S 48E S34
DABD


SH-7116
4S 48E S29
CCAD


SH-7117
5S 48E S7
BCAA



SH-7118
5S 48E S22
DCDA


SH-7120
4S 48E S36
CCCC
	 r 	
sampled

70 to
95ft.



40 to
56ft.



30 to
37ft.
190to
192 ft.

72 to
82ft.

114 to
119ft.

38 to
41 ft.
78 to
86ft.

70 to
72ft.
sample bed A13O3 CaO FejOa K2O MgO Na2O P2OS SiOj SO3 TiO2 Total
Pawnee 22.8 14.1 4.8 .6 4.2 6.3 .4 33.7 10.6 .7 98.2

362-364


Pawnee 19.1 21.3 4.2 .2 7.4 .9 .4 34.8 7.9 .9 97.1

365-366


Pawnee 10.1 22.5 ' 10.8 .2 2.3 .7 .2 16.5 27.4 .3 91.0

367
Pawnee 17.7 3.4 10.4 3.0 2.3 .8 .1 50.3 5.2 .7 93.9
372
Cook 11.7 21.7 8.2 .4 5.5 7.2 .1 18.7 21.4 .4 95.3

368

Cook 13.5 15.4 11.8 .5 3.7 4.0 .2 22.7 22.2 .4 94.4
369
Canyon 11.7 22.0 9.6 .4 5.7 2.5 1.3 19.2 22.3 .4 95.1

370
Cook 11.5 24.2 7.9 .4 6.9 2.4 .8 18.7 23.5 .3 96.6
371
Cook 17.3 8.2 12.4 .6 3.4 .2 .4 45.3 5.9 .9 94.6

375

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-------
                                            Table 73.-Proximate analysis, forms of sulfur, and heating value, Threemile Buttes coal deposit.
                                                                                 Proximate, %
                                                                                                    Form of sulfur. %
  Drill hole
 and location
 SII-7118
 5S R48t S22
 IKUA

 SH-7141
 4S R47E S35
 CBBA

 SH-7142
 4S R47E S23
 CBBA

 SH-7151
 4S R47E S4
 CADD
SH-7152
3SR47ES33
CBAB
 Depth
sampled
 38 to
 41 ft
 45 to
 52 ft.
 42 to
 50ft.
 90 to
 91 ft.

 91 to
 93ft.

 93 to
100 ft.
 54 to
 57ft.
 Lab.
number
 370
 392
 393
                                 408
                                 409
                                 410
                                 411
Coal
bed
                       Canyon
                       Canyon
                       Canyon
                       Canyon
                       Canyon
Form of
analysis   /
             A
             B
             C

             A
             B
             C

             A
             B
             C

             A
             B
             C
             A
             B
             C
             A
             B
             C

             A
             B
             C

Moisture
36.960


36.820


38.100


36.390


38.230


38.680


36.190


Volatile
matter
26.709
42.369
47.054
27.686
43.821
47.013
26.517
42.839
45.685
25.199
39.615
45.888
26.227
42.460
46.733
25.684
41.886
46.157
26.627
41.729
45.021
Fixed
carbon
30.054
47.674
52.946
31.204
49.389
52.987
31.527
50.932
54.315
29.716
46.715
54.112
29.894
48.396
53.267
29.962
48.861
53.843
32.516
50.958
54.979

Ash
6.277
9.957

4.290
6.790

3.856
6.230

8.695
13.670

5.649
9.145

5.674
9.253

4.667
7.314


Sulfur
.955
1.516
1.683
.451
.714
.766
.389
.628
.670
2.547
4.004
4.637
.988
1.599
1.760
.658
1.072
1.182
.604
.947
1.021

Sulfate
.022
.035
.039
.027
.043
.046.
.034
.054
.058
.084
.133
.154
.020
.033
.036
.054
.088
.097
.022
.034
.036

Pyritic
.235
.373
.414
.061
.097
.104
.067
.108
.116
1.520
2.389
2.767
.291
.471
.518
.108
.177
.195
.230
.361
.389

Organic
.698
1.108
1.230
.362
.573
.615
.288
.466
.497
.943
1.482
1.717
.676
1.095
1.205
.495
.807
.889
.352
.552
.596
Heating
value (Btu)
6904
10951
12162
7080
11206
12022
6904
11153
11894
6716
10559
12230
6688
10828
11918
6646
10838
11943
7133
11179
12061




CO
2
•3
CD
M
O
O
r
co
o
G
X
PI
CO
»
Z
MONTANA



 /A, as received; B, moisture free; C, moisture and ash free.

-------
Drill hole
and location



SH-7118
5S48ES22
DCDA

SH-7141
4S 47E S35
CBBA

SH-7142
4S47ES23
CBBA


SH-71S1
4S 47E S4
CADD
SH-7152
3S47tS33
CBAB
Table 74. -Major ash constituents, Threemile Buttes coal deposit.
Depth Lab. Coal Constituent, %
sampled sample bed A12O3 CaO FejOa KjO MgO NaaO P2O5 SiOj S03 TiO2 Total


•
Canyon 11.7 22.0 9.6 .4 5.7 2.5 1.3 19.2 22.3 .4 95.1
38 to
41 ft. 370

Canyon 8.9 34.2 5.8 .2 9.0 1.0 1.5 17.1 19.1 .4 97.2
45 to
52 ft. 392

Canyon 8.9 28.7 7.5 .2 12.9 2.0 1.0 14.6 19.3 .4 95.5
42 to
50 ft. 393


Canyon 9.5 20.1 9.8 .1 6.5 2.4 2.2 11.2 27.8 .3 89.9
90 to
100 ft. 408-410
Canyon 7.1 23.8 9.8 .2 15.0 .7 .1 15.4 24.0 .4 96.5
54 to
57ft. 411
INDIVIDUAL DEI
V
O
a
H
T
Cfl
O
z
55
w
H
w
s
ft
a

P
n
03
^
n
CO






u>

-------
114
                STR1PPABLE COAL, SOUTHEASTERN MONTANA
formed where it burned produces very steep ridges on the
sides of Pumpkin Creek valley. The coal bed consists of
two benches 22 feet apart at the north and about 40 feet
at the southeast side of the mapped area. The upper bench
is 10 feet thick as measured in drill hole SH-7117 and 16
feet  in SH-7119 in sec.  12, T. 5 S., R.  48 E. The lower
bench is 6 feet thick in SH-7119 and 10 feet in drill hole
SH-7117.

   About 50 feet above the Cook beds is the Ferry coal
bed, and 50 to  100 feet higher is the Canyon coal bed,
which consists of two benches in T. 5 S., R. 47  and 48 E.,
shown on the Threemile Buttes coal deposit (PI.  24). In
drill hole SH-7121, sec. 16, T. 6 S., R. 48 E., in the Dia-
mond Butte coal deposit (PI. 19), the Canyon is a single
bed 7 feetthick, and in SH-7136 in sec. 33,T. 5 S., R. 47 E.,
it is 6 feet thick. One bench of the Canyon bed thickens
northward and in SH-7141 in sec. 35, T. 4 S., R. 47 E.,
 it is 13 feet  thick. In drill hole  SH-7143, sec.  15,
 the  upper bench is 4 feet thick and the lower bench 13
 feet.

   The  Ferry coal  bed is thin and discontinuous in the
 southern part of the area, but in the northern part it is 17
 feet thick in drill hole SH-7152, sec. 33, T. 3 S., R.47 E.,
 and  13  feet thick in drill hole SH-7151, sec. 4, T. 4  S.,
                                        R.47E. In drill hole SH-7142, sec. 23, T.4 S., R.47 E., it
                                        is 6 feet thick.

                                                           COAL QUALITY

                                           Nineteen core samples were obtained on this project
                                        and were analyzed by the Montana Bureau of Mines and
                                        Geology analytical laboratory. Proximate analysis, forms
                                        of sulfur, and heating value are shown for  the Sonnette
                                        coal  deposit in Table 71 and for the Threemile Buttes
                                        coal  deposit in Table 73.  Major ash constituents in the
                                        Sonnette coal deposit are shown in Table 72 and in the
                                        Threemile Buttes coal deposit in Table 74.

                                                          COAL RESERVES

                                           The indicated  reserves  in the  Pawnee  coal  bed are
                                        320,250,000 tons, and inferred reserves  are 183,060,000
                                        tons, a total of 503310,000 tons. The two benches of
                                        the Cook coal bed have indicated reserves of 362,980,000
                                        tons, and total  reserves in  the Sonnette coal deposit are
                                        866,290,000 tons (Table 70).

                                           The Canyon coal  bed and the  Ferry coal bed in the
                                        Threemile Buttes deposit  contain indicated reserves of
                                        225,400,000  tons (Table 74).
                Table 75.-Reserves, overburden, overburden ratio, acres, and tons/acre, Home Creek Butte coal deposit.
                                             CANYON and FERRY BEDS
     Thickness of
     overburden, ft.
   Indicated reserves,
      million tons
Overburden and
  interburden,
 million cu. yd.
   Overburden and
   interburden ratio,
   cubic yards/ton
         Acres
                  Tons/acre
        Oto  50
       SO to 100
       100 to 150
        36.59
        93.71
        86.91
Total   217.21
                                      Total
     46.34
    269.49
    363.47
    679.30
        1.26
        2.87
        4.18
Average  3.12
Total
  870.4             42,038.1
2,227.2             42,075.3
1.753.6             49.560.9
4,851.2     Average  44,774.5
        HOME CREEK BUTTE COAL DEPOSIT

                      LOCATION

    The Home Creek Butte coal deposit (PI. 26) is in T. 2
  and 3 S., R.47 E., and a very small portion of the deposit
  laps over into sec. 24 and 25, T. 2 S., R. 46 E., Powder
  River County.  U.S. Highway 212  crosses the southern
  boundary of the mapped area. On the west, the area bor-
  ders the  Ashland coal deposit (PI. 13), and on the south,
  it nearly adjoins the Threemile Buttes coal deposit (PI.
  24). To  the  east,  the area nearly adjoins the Pumpkin
                                        Creek coal deposit (PI. 15), and it is overlapped on the
                                        north by the Little Pumpkin Creek coal deposit (PI. 27).

                                                 FIELD WORK AND MAP PREPARATION

                                           The field work was completed in  1971  and included
                                        the drilling of two holes, SH-7153 and SH-7154, sec. 10,
                                        T. 3 S., R. 47 E. Data from an additional hole  in sec. 33,
                                        T. 2 S., R. 47 E., were obtained from  a private company.
                                        Clinker and burn lines were mapped in  the winter of 1972
                                        with the aid of colored aerial photos  borrowed from the
                                        U.S. Forest Service.

-------
                                INDIVIDUAL DEPOSITS—LITTLE PUMPKIN CREEK
                                                                                                         115
             PREVIOUS GEOLOGIC WORK

   The Home Creek Butte coal deposit area was mapped
by Bass (1932).

                  LAND OWNERSHIP

   The Home Creek Butte coal deposit lies  within the
Custer National  Forest. The Federal Government owns
the surface and coal.

         SURFACE FEATURES AND LAND USE

   The Home Creek Butte coal deposit is on the high di-
vide separating Little Pumpkin Creek from the East Fork
of Otter Creek and Home Creek, both of which are tribu-
taries of Otter Creek. Beaver Creek drains the northwest-
ern part of the area.

   The principal land use in the area is livestock grazing,
but some land is cultivated by dry-land farming to pro-
duce wheat  and other  grain. Some timber is cut in the
area and hauled to nearby Ashland for saw lumber.

                GEOLOGIC STRUCTURE

   Very little structural information is available  in this
area, but the information that is available indicates that
                                     the Ferry coal bed is nearly horizontal. The altitude of
                                     its top in sec. 33, T. 2 S., R. 47 E., is 21 feet lower than
                                     in drill hole SH-7154, sec. 10, T. 3 S., R. 47 E.

                                                          COAL BEDS

                                        The Ferry coal bed is 24 feet thick, and in drill hole
                                     SH-7154, it is 76 feet below the Canyon bed, which is 10
                                     feet thick. In T. 2 S., R. 47 E., only the Ferry coal bed
                                     contains strippable reserves. Although the Canyon coal
                                     bed may remain unburned in some places, it has only mini-
                                     mal reserves. The names Ferry and Canyon have been car-
                                     ried north from the Birney-Broadus area (Warren, 1959),
                                     where they are correlated with the coal beds in the Three-
                                     mile Buttes coal deposit (PI. 24) to the south.

                                                         COAL QUALITY

                                        No analytical data were collected or available for coal
                                     in this coal deposit. It was assumed that the coal is similar
                                     to that in the Threemile Buttes coal deposit farther south.

                                                        COAL RESERVES

                                        The indicated reserves in the Ferry and Canyon coal
                                     beds are 217,210,000  tons (Table 75).
             Table 76.-Reserves, overburden, overburden ratio, acres, and tons/acre, Little Pumpkin Creek coal deposit.
                                        SAWYER, A, C and D, X, and E BEDS
    Thickness of
    overburden, ft.
Inferred reserves,
  million tons
    Overburden and
     interburden,
    million cu. yd.
               Overburden and
               interburden ratio,
               cubic yards/ton
                         Acres
                                  Tons/acre
       Oto 50
      50 to 100
     100 to 150
       0 to 100
                Total
    69.06
    55.74
    46.38
    44.65
   215.83
Total
 179.70
 264.71
 457.87
 231.56
1,133.84
Average
2.6
4.7
9.8
5.2
5.3
Total
2,205.4
2,015.2
1,433.6
2.880.0
8^34.2
Average
31,314.0
27,659.8
32,352.1
15.503.5
25,290.0
      LITTLE PUMPKIN CREEK COAL DEPOSIT

                     LOCATION

   The Little Pumpkin Creek coal deposit (PI. 27) is in
T. 1 and 2 S., R.47 and 48 E., Powder River County. The
deposit, confined to the sides and bottom of the valley
of Little Pumpkin Creek, is overlapped on its north side
by the Foster Creek coal deposit (PI. 16A, B, and C).The
area adjoins the Pumpkin Creek coal deposit (PI. 15) to
                                     the east, the Beaver Creek-Liscom Creek coal deposit
                                     (PI. 29) to the northwest, the Ashland coal deposit (PI.
                                     13A and B) to the west, and the Home Creek Butte coal
                                     deposit (PI. 26) to the southwest.

                                              FIELD WORK AND MAP PREPARATION

                                        The field work in the  Little Pumpkin Creek coal de-
                                     posit was minimal and included only brief reconnaissance
                                     mapping on 7&-minute topographic quadrangle maps.

-------
116
                                 STRIPPABLE COAL, SOUTHEASTERN MONTANA
Color aerial photos lent by the U.S. Forest Service were
utilized for  drawing the  coal outcrops and burn lines.
Some private company drill holes shown on the map (PI.
27) as L.P.C. drill holes, provided information on coal
thickness, and the report by  Bass (1932) provided addi-
tional figures on coal thickness.

             PREVIOUS GEOLOGIC WORK

   The Little Pumpkin Creek area was included in the re-
port on the Ashland coal field (Bass, 1932).

                  LAND OWNERSHIP

   The  Little Pumpkin Creek area lies within the land
grant to Burlington  Northern, Inc., which has retained
the coal rights, although it has conveyed the surface. The
State of Montana owns the surface and minerals in sec. 16
and 36 in T. 1 S., R. 47 and 48 E., and some additional
land in T. 1 S., R. 47 E. The Federal Government owns a
large part of the surface and some coal rights in T. 2 S.,
 R. 47 and 48 E., besides that part of the area included
 within Custer National Forest.

          SURFACE FEATURES AND LAND USE

    Little  Pumpkin  Creek has deeply  incised a broad
 northward-trending valley, on both sides of which  the
 terrain  rises to steep-sided, high ridges. Clinker zones are
 numerous. Little Pumpkin Creek and its tributaries are
 intermittent streams, but Little Pumpkin Creek and some
 of the larger tributaries contain ponds of water all year.

    The principal land uses in the area are livestock grazing,
 the raising of hay in valley meadows, and dry-land farming
 on summer fallowed fields. Dense forests on the west side
 of Little Pumpkin Creek support logging operations.

                GEOLOGIC STRUCTURE

    Very little information on the structure is available,
 but the strata seem to be almost horizontal.

                     COAL BEDS

    The coal beds in the Little Pumpkin Creek area that
 contain strippable coal are, from  top to bottom, the E,
X, C and D, Sawyer, and A beds. The Knobloch bed may
be counted also, because it contains strippable coal along
Little Pumpkin Creek (PI. 16A).

   The E coal bed, about 7 feet thick (Bass, 1932), is 70
to 100 feet above the X bed. The X coal bed is about 8
feet thick and is about 40 to 80 feet above the C and D
bed. Thickness of the clinker where the C and D coal beds
have burned  along Green Creek in the northern part of
T. 2 S., R. 47 E., and along Stacey Creek in the southern
part of T. 1 S., R. 47 E., indicates a coal  thickness in ex-
cess of 10 feet.

   The C and D coal beds are 80 to 100 feet above the
Sawyer bed,  which is 31 feet thick in drill hole PC-31,
sec. 21, T. 2 S., R.48 E. (PI. 15). According to Carmichael
(1967), the A bed splits from the Sawyer somewhere be-
tween  PC-31  and sec. 32, T. 1 S., R. 48 E. The parting
between the A bed and the Sawyer bed is prominent on
both sides of Little Pumpkin Creek and averages about
40 feet in thickness. Farther south along Little Pumpkin
Creek in the gamma log of an oil well in sec. 23, T. 2 S.,
R. 47 E., the Sawyer bed is 31 feet thick and seems to be
combined with the A bed in this area. A coal bed 5 feet
thick here lies 12 feet above the Sawyer bed.

   The Sawyer and  A coal beds thin on the west side of
Little Pumpkin Creek in the center of T. 1 S., R. 47 E., and
range in thickness from 6 to 9 feet.

                   COAL QUALITY

   No  core samples have been obtained  from the Little
Pumpkin Creek area, but the quality  is believed to be
similar to that in the Pumpkin Creek, Foster Creek, and
the Beaver Creek-Liscom Creek areas.

                   COAL RESERVES

   The coal reserves in the Little Pumpkin Creek  area are
classified as inferred because of the lack of drill  holes in
the  area. The inferred reserves in the E coal bed, the X
coal bed, the  C and D coal bed, the Sawyer coal bed, and
the A coal bed total 215,830,000 tons (Table 76).

-------
                                     INDIVIDUAL DEPOSITS—SAND CREEK
                                                                                                         117
                 Table 77.-Reserves, overburden, overburden ratio, acres, and tons/acre, Sand Creek coal deposit.
                                                KNOBLOCH BED
   Thickness of
  overburden, ft.
Indicated reserves,
  million tons
 Overburden,
million cu. yd.
Overburden ratio,
 cubic yards/ton
         Acres
        Tons/acre
      Oto  50
     50 to 100
    100 to 150
              Total
                  Total
    138.26
    306.35
    148.05
    592.66
                                                       Average
      1.4
      2.3
      3.9
      2.22
Total
        36,974.2
        51,145.6
        52,070.8
Average  44,914.4
          SAND CREEK COAL DEPOSIT

                     LOCATION

   The Sand Creek coal deposit (PI. 28) is in portions of
T. 1 N. and 1 S., R. 49 and 50 E., Custer and Powder River
Counties. The area is about 50 miles south of Miles City
on U.S. Highway 312, which traverses the southwest cor-
ner of the area. The Sand Creek coal deposit is a few miles
north of the Broadus coal deposit (PI. 17) and a few miles
east of the Foster Creek coal deposit (PI. 16A, B, and C).

        FIELD WORK AND MAP PREPARATION

   Field work in the Sand Creek coal deposit, completed
in 1967 under a  cooperative project between Burlington
Northern, Inc., and the Montana Bureau of Mines and
Geology, consisted of three drill holes and an altimeter
survey conducted to gather topographic information for
control in preparation of an overburden  map. The field
procedures followed those established  by Burlington
Northern  (Carmichael,  1967). A structure-contour and
overburden map was prepared by Loren A. Williams of
Burlington Northern, Inc.

             PREVIOUS GEOLOGIC WORK

   The southern part of the Sand Creek coal field was
mapped and described in the U. S. Geological Survey re-
port on the Coalwood  coal field (Bryson, 1952). The
northern part of the  area is included  in U, S. Geological
Survey report on the  Mizpah coal  field (Parker and
Andrews,  1939). Brown'and  others (1954) and Ayler,
Smith, and Deutman (1969) also describes the strippable
coal.

                  LAND OWNERSHIP

   The Sand Creek coal deposit lies within the boundaries
of the land grant to Burlington Northern, Inc. Although
                                      the railroad has conveyed the surface, it has retained own-
                                      ership of the  coal in odd-numbered sections within the
                                      area.  The State of Montana owns sec. 16 and 36 in each
                                      township including both surface and mineral rights; the
                                      rest of the surface is privately owned. Although individ-
                                      uals may own a  small amount of coal, the Federal Gov-
                                      ernment retained the coal rights on most of the even-
                                      numbered sections.

                                                SURFACE FEATURES AND LAND USE

                                         The Sand Creek coal deposit is in a mesa that has a
                                      rolling surface particularly well  suited for strip mining.
                                      In the south end of the deposit, the sides of the mesa
                                      are very  steep and dissected, but the top is flat or gently
                                      rolling.

                                         Approximately  three-quarters of the area is utilized
                                      for dry-land farming. The  rest is used for livestock graz-
                                      ing. Thick clinker  above the burned Knobloch coal bed
                                      retains adequate  moisture to support stands of ponderosa
                                      pine trees along the sides of the mesa.

                                                      GEOLOGIC STRUCTURE

                                         Although very little structural information is available,
                                      altitudes of the top of the Knobloch coal bed, as m asured
                                      in drill holes, show that the  strata dip to the north (r'. 28).

                                                           COAL BEDS

                                         The Knobloch  coal  bed,  in  the  lower  part of the
                                      Tongue River Member,  contains the strippable  coal re-
                                      serves in the Sand Creek coal deposit. The Knobloch bed
                                      consists of two to four distinct benches. In drill hole SC-1,
                                      sec. 23,  T. 1  N., R. 49 E., the Knobloch bed is in two
                                      benches; the upper bench is 17 feet thick, the lower is 15
                                      feet, and the parting is only 3 feet. About 2 miles south-
                                      west, in drill hole SC-3, sec. 1, T. 1 S., R.49 E., the Knob-
                                      loch is split  into four distinct benches. The upper Knob-

-------
                                                   Table 78.-Ptoximate analysis, ultimate analysis, and heating value, Sand Creek coal deposit.
                                                                                                                                                                            00
  Drill hole
 and location
SC-1C
IN 4^1:
COK
S23
            Depth
           sampled
51 to
68 ft

71 to
86 It.
              USBM
              number
                          1-73091
                                 1-73092
Coal
bed
                                             Knobloch
Form of
analysis  /
             A
             B
             C
             A
             B
             C


Moisture
31.10


32.57


Proximate^ '
Volatile
matter
27.81
40.37
45.89
28.30
41.97
45.38
* Ultimate. %
Fixed
carbon
32.81
47.61
54 11
34.06
50.52
54.62

Ash
8.28
12.02

5.07
7.51


Sulfur
.29
.42
.48
.31
46
.50

Hydrogen
6.46
4.36
4.96
6.71
4.59
4.96

Carbon
43.14
62.62
71.17
44.64
66.20
71.58

Nitrogen
.63
.92
1.04
.65
.96
1.04

Oxygen
41.20
19.66
22.35
42.62
20.28
21.92
Heating
value (Btu)
7220
10480
11910
7460
11060
11960
 /A, as received, B, moisture free; C, moisture and ash free.
 Drill hole       Depth       Lab.
and location    sampled     sample
                                                                                                                                                                    5









Table 79. -Major ash constituents and fusibility of ash, Sand Creek coal deposit.


Fusibilitv of ajh.°F
Initial
Coal Constituent, % deformation Softening Fluid
bed A12O3 CaO FejO3 KjO MgO NajO PjO5 SiOj SO3 TiOj Total tomp. temp. temp.
o
0
f-
tn
o
s
X
PI
>
en
P)
Z
Z,
O
2j

>
>
SC-1C           51 to      GF-67-      Knobloch     13.2    20.2    4.6       .63   6.6    1.9       .63      45.5    6.6    .84   100.7       2120
IN 49E S23      68 ft.      794
                71 to      GF-67-
                86 ft.      795
                                            12.5    33.0   6.4      .64   7.7     .50    1.04     20.0  12.4   .45   94.6      2460
                                                                                                                                            2160       2200
                                                                                                                                2500      2540

-------
                             INDIVIDUAL DEPOSITS—BEAVER CREEK-LISCOM CREEK
                                                                                                       119
loch bench seems to have split into three benches, 7 feet,
8 feet, and 8 feet thick; the lower or fourth bench is 14
feet thick. In drill hole SC-2, in sec. 9, T. 1 S., R. 50 E.,
the Knobloch bed again  is in  two benches;  the upper
bench is 7 feet thick and the lower bench is 10 feet. The
thickness of the parting between  the upper  and lower
benches of  the Knobloch coal bed increases markedly
from north to south across the coal deposit. At the north-
ern end, the two benches are separated by a 3-foot part-
ing in drill hole SC-1C, but in drill hole SC-2, thickness
of the parting has increased to 43 feet.

                   COAL QUALITY

   Both benches of the Knobloch coal bed were cored in
drill hole SC-1C, sec.  23, T. 1  N., R. 49 E., during  the
1967 cooperative field program. The cores were analyzed
by the U.S. Bureau of Mines, Grand Forks Coal Research
Laboratory.  Proximate analysis, ultimate analysis, and
heating value are shown in Table 78; major ash constitu-
ents and fusibility of ash are shown in Table 79.

                  COAL RESERVES

   Reserves in the Knobloch coal bed total 267,340,000
tons (Table 77).


  BEAVER CREEK-LISCOM CREEK COAL DEPOSIT

                     LOCATION

   The Beaver Creek-Liscom Creek coal  deposit is in
T. 1 N. and  1 S., R. 45 and 46 E. (PI. 29), Powder River
and Rosebud Counties. The northern and western bound-
aries of the coal deposit are the lowlands along the valley
of the Tongue River where erosion has removed the coal
beds, and the southern boundary is the  high area of the
Cook Mountains where overburden is too great for  po-
tential strip mining of the  coal. To the east, the area bor-
ders the Foster Creek coal deposit (PI. 16A, B, and  C),
and to the southeast it borders the Little Pumpkin Creek
coal deposit  (PI. 27). To the south, the area borders  the
Ashland coal deposit (PI. 13A and B).

         FIELD WORK AND MAP PREPARATION

   The field work in the Beaver Creek-Liscom Creek area,
completed in the summer of 1970, included drilling num-
erous exploration holes and mapping the surface on topo-
graphic quadrangle maps  and on black-and-white aerial
photos.  Color photos, borrowed from the US. Forest
Service, were used in mapping the  south half of T. 1  N.,
R. 46 E., and T. 1 S., R. 45 and 46 E.
             PREVIOUS GEOLOGIC WORK

   The Beaver Creek-Liscom Creek area was included in
the report  on the Ashland coal field (Bass, 1932). The
eastern corner of the mapped area overlaps the Foster
Creek coal deposit (PI. 16A,  B, and C), which was dis-
cussed in Montana Bureau of Mines and Geology Bulletin
73 (Gilmour and Williams, 1969), and two drill holes in-
cluded in the Foster Creek report are shown on Plate 29.

         SURFACE FEATURES AND LAND USE

   The most prominent surface features in the mapped
area are the wide northwest-trending valleys of Liscom
Creek and Beaver Creek, both tributaries of the Tongue
River. The area is characterized by gently rolling grassland
and long steep-sided clinker-capped ridges. The divide be-
tween Liscom Creek  and Beaver Creek is a  dissected
ridge bordered by steep slopes and cliffs of thick resistant
clinker formed by the burning of the Knobloch coal bed.

   The principal land use in the area is livestock grazing,
supplemented by dry-land farming. The principal crops
are hay and grains.

                  LAND OWNERSHIP

   The Beaver Creek-Liscom Creek coal deposit lies with-
in the land grant to Burlington Northern, Inc., and the
coal on the odd-numbered sections has been retained by
the railroad, although the surface has been conveyed. The
State of Montana owns the surface and the minerals  in
sec. 16 and 36 of each township and some additional land
in T. 1 S., R.45 and 46 E. The Federal Government owns
the coal in  most of the rest of the area  and has a fairly
large amount  of the surface in T. 1 N.,  R. 45 E., and a
few isolated tracts in T. 1 N., R. 46 E., besides the part
of T. 1 S., R. 46 E., that is within the  Custer National
Forest.

               GEOLOGIC STRUCTURE

   The strata  in the Beaver Creek area are almost hori-
zontal but  dip slightly to the west. The Knobloch coal
bed is structurally highest in drill hole SH-7083, in sec. 2,
T. 1 S., R. 46 E. This structural high seems to coincide
with the divide between Beaver Creek and Liscom Creek.
A northeast-trending fault in the  vicinity of drill hole
SH-7078, sec. 36, T. 1 S., R. 45 E., has downdropped the
strata on the southeast side about 40 feet.

                     COAL BEDS

   The coal beds that have economic value in the Beaver
Creek-Liscom Creek coal deposit are, from top to bottom,
the Knobloch, Flowers-Goodale,  and Terret beds. The

-------
120
                  STRIPPABLE COAL. SOUTHEASTERN MONTANA
           Table 80.-Reserves, overburden, overburden ratio, acres, and tons/acre, Beaver Creek-Uscom Creek coal deposit.
                                 TERRET, FLOWERS-GOODALE.and KNOBLOCH BEDS
   Thickness of
   overburden, ft.
   Indicated reserves,
      million tons
   Overburden and
    interburden,
    million cu. yd.
   Overburden and
   interburden ratio,
   cubic yards/ton
         Acres
        Tons/acre
       Oto  50
      SO to 100
     100 to ISO
        175.80
        294.89
        156.80
Total    627.49
                                      Total
        490.10
       1,559.98
       1.069.82
       3,119.90
        2.78
        5.29
        6.82
Average  4.97
        8,236.8
       12,441.6
        S.248.0
Total   25,926.4
        21,343.2
        23,701.1
        29.878.0
Average  24,203.1
                                                  KNOBLOCH BED
       Oto  50
      SO to 100
     100 to 150
                Total
                      Total
        292.13
        938.91
       1.069.82
       2,300.86
        2.40
        4.40
        6.82
Average  4.68
                                                                          Total
        4,518.4
        7,308.8
        5.248.0
       17,075.2
        26,934.3
        29,159.4
        29.878.0
Average  28,791.8
                                                   TERRET BED
    Thickness of     Indicated reserves,
    overburden, ft.      million tons
       Oto  SO
          10.26
                           Overburden,
                          million cu. yd.
         51.45
                      Overburden ratio,
                       cubic yards/ton
                                                                  5.01
                          Acres
                           966.4
                           Tons/acre


                            10,616.7
                                             FLOWERS-GOODALE BED
       Oto  50
      SO to 100
         43.84
         81.77
Total     125.61
        146.52
        621.07
Total    767.59
        3.34             2,752.0
        7.59             5.132.8
Average  6.11     Total    7,884.8
                            15,930.2
                            15.930.9
                    Average  15,930.7
  Knobloch coal bed contains the largest amount of strip-
  pable reserves in the area and has a maximum measured
  thickness of 22 feet in drill hole SH-7075, sec. 32,T.  1 S.,
  R. 45 E. It thins and splits northeastward and has a thick-
  ness of 14 feet  in two benches in drill hole  SH-7091,
  sec.  16, T. 1 N., R. 46 E. The lower bench of the Knob-
  loch has previously been mapped as the Lay Creek  coal
  bed in parts of the area, but drill hole SH-7075, sec. 32,
  T. 1 S., R. 45 E., indicates that the Lay Creek bed is a
  split from the Knobloch bed. Throughout T. 1 S., R. 45
  and 46 E., the "Lay Creek" coal bed maintains a thick-
  ness of 5 to 6 feet, except in drill hole SH-7083, where
  it is only 4 feet thick. The Flowers-Goodale bed is thick-
  est in the northeast part of the area. In drill hole SH-7083,
                                            in sec. 2, T. 1 S., R. 46 E., it is 12 feet thick; in drill hole
                                            SH-7076, in sec. 14, T. 1 S., R. 45 E., it is 9 feet thick.
                                            The Tenet coal bed is 10 feet thick in drill hole SH-7083
                                            and 6 feet thick in drill hole SH-7076.

                                               The thick stratigraphic section penetrated in drill hole
                                            SH-7083 shows the relationship of the coal beds. In this
                                            drill  hole, the section between the Knobloch and "Lay
                                            Creek" beds  a at  its maximum of 88  feet, from top to
                                            top. The  section between the Flowers-Goodale and Terret
                                            beds is 43 feet, about the same as in drill hole SH-7076.
                                            In SH-7083, the  section  between  the Knobloch  and
                                            Flowers-Goodale beds is 188 feet, and it decreases west-
                                            ward to about 100 feet in sec. 36, T. 1  N., R. 45  E.

-------
                                       Table 81 .-Proximate analysis,' forms of sulfur, and heating value, Beaver Creek-Liscom Creek coal deposit.
                                                                                   oximate. %
Form of sulfur. %
 Drillhole
and location
SH-7074
IS 4SE S20
BAAD
SH-7076
1S45ES14
ODBD

SH-7077
1S4SES34
ABBB
SH-7079
1S46K S28
BBCC

SH 7080
is 46i  S:H
f'ACM
SI I 7081
IS46I' -S2
t  (( I)

SH 7084
IN 451 VJf>
HA Ml)

•M-ltm
IN46I'M»
•;ll -70V ;
lit M,\
Depth Lab.
sampled number

100 to
106 ft. 307

106 to
116ft. 308

116 to
120ft. 309

53 to
62ft. 311

92 to
100ft. 312

1 00 to
109ft. 313

42 to
52ft. 314
85 to
95 ft. 315

95 to
100 II 3Ui


10) to
105 II, 1IH
54 lo
M It 119

67 to
77 ft, I.M>

9 1 lo
101 ll U2

'il lo
',0f|. \J\

.in- „«
Coal
bed
Knobloch








Flowers-
Goodale

Knobloch





Knobloch


Knobloch





Kitohloi'h

Howcu-
(illOllulO
Knoliloch





Kiioliliu'li


1 curl

Form of i
analysis /
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

A
B
C
A
It
C'
A
I)
C
A
II
C
A
II
C
A
(l
C

Moisture
27.530


28.010


29.160


27.770


28.910


30.220


30.530


29.740

3 1 .080



26.140

29.000
27.570


29.760


29.580


28.990

Volatile
matter
28.517
39.349
43.659
28.170
39.131
44.962
25.519
36.024
40.168
28.100
38.904
43.848
28.094
39.518
43.203
27.678
39.665
42.773
26.697
38.429
42.324
27.247
38.781
43.415
37.536
54.463
59.488

29.876
40.456
47.955
11
26 598
36.7 2 3
•15. A78
27.421
39.038
44.211
28.4H5
40.450
45 III
26.921
V/,912
41.26.1
Fixed
carbon
36.800
50.780
56.341
34.484
47.901
55.038
38.013
53.660
59.832
35.986
49.821
56.152
36.933
51.952
56.797
37.031
53.069
57.227
36.380
52.368
57.676
35.512
50.544
56.585
25.563
37.091
40.512

32.427
43.904
52.047
-^•850
.51.901
56.310
.12.016
44.203
54.622
34.571
49.218
55.767
34 639
49 217
54*889
38 122
li:/*?

Ash
7.154
9.871

9.336
12.968

7.308
10.316

8.144
11.275

6.063
8.529

5.071
7.267

6.394
9.203

7.501
10.675

5.821
8.446


11.557
15.647
m
13.816
19.074

8249
11.744

7.276
10.332

5,767
tUM

Sulfur
.496
.684
.759
.512
.711
.817
.241
.341
.380
.961
1.331
1.500
.600
.844
.923
.413
.593
.639
.472
.680
.749
.279
.397
.444
.199
.289
.315

.856
1.159
1.374
.380
•813
l'l22
1^86
too
f.093
1.238
263
373
416
691
IJX59

Sulfate
.016
.022
.025
.008
.011
.013
.008
.012
.013
.016
.022
.025
.032
.045
.049
.008
.011
.012
.008
.011
.012
.016
.023
.025
.017
.024
.026

.026
.035
.041
110
.154
.168
.017
.023
.029
.016
.023
.026
.000
.000
.000
025
.035
.038

Pyritic
.366
.505
.560
.179
.248
.285
.092
.129
.144
.759
1.051
1.185
.456
.641
.701
.195
.279
.301
.325
.468
.515
.104
.147
.165
.017
.024
.026

.548
.742
.879
.127
178
.193
516
.713
.881
.509
.725
.821
.008
.012
.013
.499
.703
.765

Organic
.114
.157
.174
.325
.451
.519
.141
.200
.223
.186
.257
.290
.112
.158
.172
.211
.302
.325
.139
.201
.221
.159
.227
.254
.166
.241
.263

.282
.382
.453
.143
.202
.219
279
.386
.477
.242
.345
.391
.254
.361
.403
.166
.234
Heating
value (Brui
8417
11614
12886
8052
11185
12852
8237
11627
12965
8102
11217
12642
8383
11793
12892
8401
12039
12983
7871
11330
12479
.is;
12640
7925
11499
12560

7918
10721
12710
8271
11649
12639
7362
10164
12559
7771
11063
12535
7908
11230
12524
8170
11506
12523









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-------
Table 82. -Major ash constituents, Beaver Creek-Liscom Creek coal deposit.
                                                                                                                    K)
Drill hole
and location
SH-7074
1S45ES20
BAAD
SH-7076
1S45ES14
DDBD
SH-7077
IS 45E S34
ABBB
SH-7079
IS 46E S28
HBCC

SH-7080
IS46ES34
CACB

SH-7083
1S46ES2
OCCD

SH-7084
1N45ES36
BAUD
SH-7092
1N46ES18
ADDD
SH-7093
1 N 46E S30
ABCC
SH-7094
1N45ES16
BBDA
Depth
sampled

100 to
120 ft.

53 to
62ft.

92 to
109ft

42 to
52ft.


85 to
100 ft.


103 to
105 ft.


54 to
61 ft.

93 to
101 ft.

52 to
60 It

38 to
44ft.
Lab. Coal
sample bed
Knobloch

307-309
Flowers-
Goodale
311
Knobloch

312-313
Knobloch

314

Knobloch

315-316

Knobloch

318

Flowcrs-
Goodale
319
Knobloch

322
Knobloch

323
Tcrrct

324
Constituent, %
A12O3 CaO Fe2O3 K2O MgO Na2O P2O} Si02 SO3 TiO2 Total
15.9 16.5 3.8 .7 5.4 .8 .2 44.6 9.3 .7 97.9


15.3 13.2 14.7 .5 4.4 .2 .4 30.2 17.7 .5 97.1


17.2 23.0 5.6 .2 8.3 3.1 .3 24.3 15.1 .4 97.5


13.8 21.6 8.7 .1 6.7 .4 .2 31.2 15.3 .6 98.6



12.9 17.4 4.7 .2 6.3 1.2 .2 46.0 7.8 .9 97.6



7.9 14.8 7.5 .1 3.6 .7 .2 49.7 12.1 1.0 97.6



16.9 114 6.0 .8 3.8 .5 .1 50.7 7.6 .7 98 JS
•

15.2 16.8 12.8 .3 3.5 1.2 1 28.4 18.0 .6 96.9


13.6 20.5 6.4 .1 3.7 3.6 1.4 40.9 7.4 1.2 98.8


9.5 19.9 12.2 .1 7.4 1.0 .2 19.8 21.6 .2 91.9









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-------
                           INDIVIDUAL DEPOSITS—GREENLEAF CREEK-MILLER CREEK
                                                                                      123
                   COAL QUALITY

   The fifteen core samples obtained were analyzed by
the Montana Bureau of  Mines and  Geology analytical
laboratory. Proximate analysis, forms of sulfur, and heat-
ing value are shown in Table 81, and major ash constitu-
ents are shown in Table 82.

                  COAL RESERVES

   Strippable reserves in the Beaver Creek-Liscom Creek
coal deposit total 627,490,000 tons, of which the Knob-
loch bed accounts for 491,620,000 tons (Table 80).

        GREENLEAF CREEK-MILLER CREEK
                  COAL DEPOSIT

                     LOCATION

   The Greenleaf Creek-Miller Creek coal deposit (PI. 30)
in parts of T. 1 and 2 S., R. 42 and 43 E., Rosebud County,
is bounded on the south by the Northern  Cheyenne In-
dian Reservation north boundary, on the east by the
Tongue River valley, and on the west by the valley  of
Rosebud Creek.

         FIELD WORK AND MAP PREPARATION

   The field work  in the Greenleaf  Creek-Miller  Creek
area during the summer of 1970 was followed in the sum-
mer of  1972 by geologic mapping on black-and-white
aerial  photos and  7^-minute  topographic  quadrangle
maps. Overburden maps were prepared during the follow-
ing winter.

             PREVIOUS GEOLOGIC WORK
                                                        LAND OWNERSHIP

                                         The Greenleaf Creek-Miller Creek area lies within the
                                       land grant to Burlington Northern, Inc., whereby the rail-
                                       road was granted available odd-numbered sections along
                                       its right-of-way. Although the railroad has retained own-
                                       ership of the mineral rights, it has conveyed most of the
                                       surface. The State of Montana owns  sec. 16 and 36  in
                                       each township and has retained its surface and mineral
                                       rights. In the rest of the area, most of the surface is pri-
                                       vately owned, but most of the coal is owned by the Fed-
                                       eral Government.

                                               SURFACE FEATURES AND LAND USE

                                         Much of the coal deposit underlies an asymmetric ridge
                                       forming the divide between the northeastward-flowing
                                       Greenleaf Creek on the east and the northward-flowing
                                       Miller  Creek on  the west. Both of  these intermittent
                                       streams are  tributaries of Rosebud Creek. A few knobs
                                       on the crest of the ridge are capped by the clinker that re-
                                       sulted from  burning of the Sawyer coal bed. The western
                                       side  of the ridge rises abruptly from the coal outcrop to
                                       the crest, but the eastern side is broad and rolling. Farther
                                       east, the topography becomes more rugged as the clinker
                                       of the burned Knobloch bed is encountered; valleys be-
                                       come narrow and steep sided. Farther south, the clinker
                                       of the  Sawyer bed forms a sharp ridgeline.

                                         The principal land use in the area is livestock grazing
                                       supplemented by some dry-land fanning and raising of
                                       hay  in meadows  along the valley bottoms of Greenleaf
                                       Creek  and Miller Creek. The clinkered areas are covered
                                       with stands of ponderosa pine.
   The area has been mapped by the U S. Geological Sur-
vey (Bass, 1932). Strippable coal was described in later
reports by Kepferle (1954) and Ayler, Smith, and Deut-
man (1969).
                                                     GEOLOGIC STRUCTURE

                                         The strata in the Greenleaf Creek-Miller Creek coal de-
                                       posit are almost horizontal, but show an apparent dip to
         Table 83.-Reserves, overburden, overburden ratio, acres, and tons/acre, Greenleaf Creek-Miller Creek coal deposit.
                                   ROSEBUD, KNOBLOCH, and SAWYER BEDS
  Thickness of
  overburden, ft.
Indicated reserves,
  million tons
 Overburden,
million cu. yd.
Overburden ratio,
 cubic yards/ton
Acres
Tons/acre
     Oto  SO
    SO to 100
   100 to ISO
              Total
     135.8                 240.56             1.77
     196.01                823.97             4.20
     121.90                740.70             6.07
     453.71        Total  1,805.22     Average  3.97
                               Total
                      4,480.0
                      6,790.4
                      3.648.0
                     14,918.4
                  30,312.5
                  28,865.7
                  33.415.6
          Average  30,413.5

-------
                                       Table 84.-Proximate analysis, forms of sulfur, and heating value, Greenleaf Creek-Miller Creek coal deposit.
  Drill hole
 and location
 SH-7096
 1S43ES28
 DBBA
                                                                                Proximate. %
Form of sulfur. %
 SH-7097
 1S43ES34
 CBCB
SH-7098
1S43ES32
BDCC
SH-7099
2S 43E S6
BDDA

SH-70100
1S42ES36
ACBB
SH-70101
IS 42E S24
BCCA
SH-70102
1S43ES16
BADA
Depth
sampled

59 to
67ft.

67 to
74 ft.

74 to
83 ft.

43 to
45 ft.

77 to
86ft.


58 to
68ft.

68 to
78 ft.

125 to
133 ft.


92 to
100 ft.

100 to
102 ft.


43 to
50 ft.

50 to
55 ft.

41 to
51ft.

51 to
59 ft.
59 to
61 ft.

210 to
216 ft.
216to
226 ft.
Lab.
number


325


326


327


328


329



373


374


330



331


332



333


334

335


336

337


338

339
Coal
bed
Knobloch








Local


Sawyer



Sawyer





Sawyer



Knobloch






Rosebud





Knobloch






Rosebud




Form of
analysis
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

A
B
C
A
B
C
A
B
C

A
B
C
A
B
C

A
B
C
A
B
C
A
B
C
A
B
A
B
C
A
B
C
A
B
C
i
/ Moisture
27.930


27.180


28.050


28.610


29.060



24.100


28.160


26.150



26.330


23.610



27.080


26.300


28.060

28.670

29.410


27.830


27.490

Volatile
matter
28.271
39.228
43.285
28.201
38.727
42.255
26.677
37.077
41.325
25.223
35.331
49.675
27.315
38.504
41.214

31.631
41.675
46.233
27.706
38.566
41.155
29.960
40.569
44.084

29.504
40.049
43.305
31.894
41.751
45.339

27.115
37.184
40.975
26.189
35.535
42.670
27.392
38.076
41.901
28.165
39.486
43.318
27.883
39.500
43.643
27.453
38.039
41.967
26.213
36.151
40.978
Fixed
carbon
37.043
51.399
56.715
38.539
52.924
57.745
37.877
52.643
58.675
25.554
35.794
50.325
38.961
54.920
58.786

36.786
48.466
53.767
39.615
55.143
58.845
38.001
51.457
55.916

38.627
52.433
56.695
38.451
50.335
54.661

39.058
53.563
59.025
35.187
47.743
57.330
37.981
52.795
58.099
36.854
51.668
36006
5L007
56.357
37.962
52.600
58.033
37.756
52.069
59.022

Ash
6.755
9.374

6.080
8.349

7.396
10.280

20.613
28.874

4.665
6.576


7.483
9.859

4.519
6.291

5.889
7.974


5.538
7.518

6.045
7.914


6.747
9.253

12.324
16.722

6.567
9.129
6.310
8.846
6.701
9.493

6.756
9.361

8.541
11.780


Sulfur
.422
.586
.646
.359
.493
.538
.617
.858
.956
1.890
2.647
3.722
.317
.447
.478

.541
.713
.791
.218
.304
.324
.214
.290
.315

.439
.596
.644
.388
.508
.552

.696
.955
1.052
2.393
3.247
3.900
.438
.609
.671
.406
.569
.624
1.253
1.775
1.961
.696
.964
1.064
.892
1.230
1.394

Sulfate
.017
.024
.026
.017
.023
.026
.042
'.059
.065
.031
.043
.061
.000
.000
.000

.026
.034
.038
.032
.045
.048
.017
.023
.025

.000
.000
.000
.000
.000
.000

.000
.000
.000
.016
.022
.026
.000
.000
.000
.000
.000
«8
.032
.036
.023
.033
.036
.024
.033
.037

Pyritic
.181
.251
.277
.111
.153
.167
.313
.435
.484
1.006
1.410
1.982
.106
.149
.159

.060
.079
.088
.024
.034
.036
.009
.012
.013

.166
.225
.243
.066
.086
.094

.593
.814
.896
2.101
2.851
3.424
.223
.310
.341
.242
.339
.372
1.169
1.656
1 830
.477
.661
.729
.716
.988
1.120

Organic
.224
.311
.343
.231
.317
.346
.262
.364
.406
.853
1.195
1.680
.211
.298
.319

.455
.600
.665
.162
.225
.240
.189
.255
.277

.273
.371
.401
.322
.422
.458

.103
.141
.155
.276
.374
.449
.215
J8
.164
.230
ffi
.087
096
!l95
.271
.299
m
.236
Heating
value (Btu)
8510
11808
13029
8692
11936
13024
8247
11461
12775
6554
9181
12908
8423
11873
12709

8815
11614
12884
8436
11743
12532
8805
11922
12955

8935
12128
13114
9238
12093
13132

8590
11780
12981
8175
11092
13319
8209
11411
12557
8432
11821
w
11867
13112
8454
11714
12924
iB»
12953











CO

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58
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59


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 /A, as received; B, moisture free; C, moisture and ash free.

-------
                                                Table 85.-Major ash constituents, Greenleaf Creek-Miller Creek coal deposit.
Drillhole       Depth        Lab.        Coal
Constituent, %
and location


SH-7096
IS 43E S28
DBBA
SH-7097
IS 43E S34
CBCB




SH-7098
1S43ES32
BDCC

SH-7099
2S 43E S6
BDDA


SH-70100
IS 42E S36
ACBB

SH-70101
1S42ES24
BCCA
SII-70102
1S43ES16
BADA


sampled sample bed A12O3 CaO FeaO3 K2O MgO Na20 P2OS SiO2 SO3 TiO2 Total


Knobloch 17.9 17.0 4.5 .7 4.8 .4 .4 38.8 9.4 .9 94.8
59 to
83 ft. 325-327
Local 20.9 3.6 9.3 2.5 1.5 .1 .2 53.1 3.1 .7 95.0
43 to
45 ft. 328

77 to Sawyer 18.1 14.9 7.2 .3 3.9 11.7 .4 28.2 11.5 .6 96.8
86 ft. 329

Sawyer 18.4 14.3 4.9 .4 3.3 9.2 .5 35.0 9.5 .7 96.2
58 to
78 ft. 373-374

Sawyer 15.4 14.1 4.5 .2 2.8 9.0 .4 41.8 8.0 .9 97.1
125 to
133 ft. 330


Knobloch 18.0 15.7 6.2 .2 5.0 4.2 .4 31.1 13.4 .7 94.9
92 to
102 ft. 331-332

Rosebud 15.6 10.5 14.5 1.2 3.7 .6 .5 38.4 10.9 .7 96.6
43 to
55 ft. 333-334
Knobloch 16.5 17.1 5.9 .1 5.1 .2 .3 35.5 13.0 .7 94.4
41 to
61 ft. 335-337
210 to Rosebud 16.0 11.0 17.8 1.0 3.4 .7 .5 35.6 10.1 .5 96.6
226 ft. 338-339

5
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                                                                                                                                                                   to

-------
126
                                 STRIPPABLE COAL, SOUTHEASTERN MONTANA
the south. The top of the Knobloch coal bed is highest in
the northern part of the deposit, 3,258 feet in drill hole
SH-70102, in sec. 16, T. 1 S., R. 43 E., and it declines to
3,218 feet in drill hole SH-7096 in sec. 28 and to 3,169
feet in drill hole SH-7098 in sec. 32.


   Two small faults have been mapped in sec. 32 and 33,
T. 1 S., R. 43 E. (Bass, 1932). The southernmost fault, in
the southwest quarter of sec.  33, is downthrown on the
south about 75 feet; the fault surface dips  steeply north-
ward. The second fault, in the northern part of sec. 32, is
downthrown on the north about 50 feet or less (Bass,
1932, p. 45).

                     COAL BEDS

   Coal beds in the Greenleaf Creek-Miller Creek coal de-
posit that have economic value are, from bottom to top,
the  Rosebud, Knobloch,  and Sawyer beds. The strati-
graphic distance between the Rosebud and the Knobloch
increases, west to east, from 89 feet in drill hole SH-70100,
sec. 36, T. 1 S., R. 42 E., to 151 feet in drill hole SH-70102,
sec. 16, T. 1 S., R. 43 E. A similar separation is indicated
by drill hole SH-7096, sec. 28, T. 1 S., R.  43 E., but the
gamma log of an oil well in sec. 34, T. 1 S., R. 43 E., shows
 a further increase to 166 feet of strata between the two
 coal beds. The Sawyer bed is 178 feet above the Knobloch
 bed in drill hole SH-7098, sec. 32, T. 1 S.,  R. 43 E.


   The Knobloch coal bed is 23 feet thick in drill hole
 SH-7096 in  T.  1  S., R. 43 E., but  thins westward to
 about 17 feet in drill hole SH-70100 in T. 1 S., R. 42 E.
 The Rosebud coal bed is 13 to 14 feet thick in T. 1 S.,
 R. 42 E., but thins eastward to 9 feet as  shown by the
 gamma log of an oil well in sec. 34, T. 1 S., R. 43 E. The
 Sawyer coal bed is 19 feet thick in drill holes SH-7098
 and SH-7099.  In drill hole SH-7097, sec. 34, T.  1  S.,
 R. 43 E., it is only 10 feet thick.

                    COAL QUALITY

    Seventeen  project core samples were  obtained and
 were analyzed by the Montana Bureau of Mines and Ge-
 ology analytical laboratory. Proximate analysis, forms of
 sulfur, and heating value  are shown in Table 84, and
 major ash constituents are shown in Table  85.

                   COAL RESERVES
    Strippable  reserves in the Rosebud, Knobloch, and
 Sawyer coal beds total 453,710,000 tons (Table 83).
            PINE HILLS COAL DEPOSIT

                     LOCATION

   The Pine Hills coal deposit (PI. 31), in T. 7 N., R. 49
and 50 E., Custer County, is 14 miles east of Miles City;
U.S. Highway  12  traverses the northwest corner of the
mapped area. Coal has been mined by underground meth-
ods at the now abandoned  Storm King mine in sec. 4,
T. 7 N., R. 49 E., but fires in 1969 and 1970 totally de-
stroyed the  old  workings  and caused the surface  to
collapse.

       HELD METHODS  AND MAP PREPARATION

   The field work for the Pine Hills coal deposit, a coop-
erative project of Burlington Northern, Inc., and the Mon-
tana Bureau of Mines and  Geology, was completed in
1968. Loren Williams was in charge of the field mapping
and was assisted by Peter Mattson of Burlington Northern
and by Gardar Dahl and Robert Lambeth of the Montana
Bureau of Mines and Geology. The field method utilized
was developed by Burlington Northern, Inc., (Carmichael,
1967). The field work included setting temporary bench
marks throughout the area  and obtaining topographic
control by careful altimeter surveys. Details on the qual-
ity and quantity  of coal were obtained by  drilling and
collecting core samples.

             PREVIOUS GEOLOGIC WORK

   The geology of the area was described in a U. S. Geo-
logical Survey report on the Miles City coal field (Collier
and Smith, 1909). Strippable coal in the Pine Hills coal
deposit was described by Brown and others (1954) and
by Ayler, Smith, and Deutman (1969).

                  LAND OWNERSHIP

   Burlington  Northern, Inc., owns  part of the odd-
numbered sections in the two townships containing the
Pine Hills coal deposit. The railroad has kept the coal al-
though it has conveyed most of the surface. The State of
Montana owns the surface and the coal in sec. 16 and 36,
T. 7 N., R. 49 E., and sec. 16, T. 7 N., R. 50 E. Although
the Federal Government has conveyed the surface, it has
retained the coal rights in the rest of the area.

         SURFACE FEATURES AND LAND USE

   The Pine Hills  coal deposit underlies a high ridge that
forms the divide  between Cottonwood Creek, an inter-
mittent stream that flows northward to the Yellowstone
River, and Mill Creek, an intermittent stream that flows

-------
                                       INDIVIDUAL DEPOSITS—PINE HILLS
                                                                                                            127
                 Table 86.-Reserves, overburden, overburden ratio, acres, and tons/acre, Pine Hills coal deposit.
                                                  DOMINY BED
   Thickness of
  overburden, ft.
Indicated reserves,
   million tons
 Overburden,
million cu. yd.
  Overburden ratio,
   cubic yards/ton
         Acres
                   Tons/acre
     Oto 50           68.45
    50 to 100           95.07
    100 to 150           30.35
               Total   193.87
                   Total
     110.73
     357.77
     198.72
     667.72
         1.61
         3.76
         6.54
Average   3.44
Total
2,080               32,908.7
2,956.8              32,153.0
 985.6              30.793.4
6,022.4     Average  32,191.5
  Thickness of
  overburden, ft.
 Inferred reserves,
   million tons
 Overburden,
million cu. yd.
  Overburden ratio,
   cubic yards/ton
         Acres
                   Tons/acre
     0 to 150
     86.09
     367.84
        4.27
         3,040
                    28,319.1
  Thickness of
  overburden, ft.
  Indicated and
 inferred reserves,
   million tons
 Overburden,
million cu. yd.
   Overburden ratio,
    cubic yards/ton
         Acres
                   Tons/acre
     0 to 150
    279.96
   1,035.06
         3.69
        9,062.4
                    30,892.5
southwestward to the Tongue River. Farther south the
divide separates the Tongue River drainage from the Pow-
der River drainage to the east. The top of the divide is
smooth and rolling,  but the edges are steep and nigged
and reveal resistant clinker  produced by burning of the
Dominy coal bed. Ponderosa pine trees line the fringes of
the divide.

   The principal land uses are livestock grazing and dry-
land farming.
                GEOLOGIC STRUCTURE
   The strata in the Pine Hills coal deposit are almost hori-
zontal. The maximum difference in the altitude of the top
of the Dominy coal bed in the three drill holes is only 22
feet.

                     COAL BEDS

   Strippable  reserves in the Pine Hills coal  deposit are
confined to the  Dominy coal bed, which consists of two
benches. The  thickness of the lower  bench ranges from
16 to 24 feet (Brown and others, 1954), but in the three
project drill holes, it ranges from 17  to 20 feet (PI. 31).
                                        The upper bench of the Dominy is 3 to 4 feet thick, as
                                        shown in the drill holes, and is 5 to 6 feet above the thick
                                        lower bench.

                                           The F coal bed, above the Dominy bed, has burned
                                        throughout the area  except for a small patch described
                                        by Collier  and Smith (1907, p. 57). Its clinker caps the
                                        buttes and ridges in the area.

                                                            COAL QUALITY

                                           Three core samples were obtained during the field eval-
                                        uation of the Pine Hills  coal deposit, and they were ana-
                                        lyzed by the U.S. Bureau of Mines, Grand Forks Coal Re-
                                        search Laboratory. Proximate analysis, ultimate analysis,
                                        heating value, and forms of sulfur are shown in Table 87.
                                        Major ash  constituents and fusibility of ash are shown in
                                        Table 88.

                                                           COAL RESERVES

                                           The indicated reserves in the Pine Hills coal deposit in
                                        the main bench of the Dominy coal bed are 193,870,000
                                        tons. Inferred reserves  in the  eastern  part  of the area
                                        amount to an additional 86,090,000 tons (Table 86).

-------
Table 87.-Proximate analysis, ultimate analysis, heating value, and forms of sulfur, Pine Hills coal deposit.
K)
00
Proximate . %
Drill hole
and location
PH-1C
7N 50F S29
ACAB
PH- 2C
7N49ES13
DCDA
PH-3C
7N49ES11
CDDD




,
/A, as received; B,


Lab. Coal
number bed
Dominy
GI--68
1865
Dominy
GF-6B-
1862
Dominy
GF-68-
1863





moisture free; C, moisture


Form of .
analysis /
A
B
C
A
B
C
A
B
C





and ash free.


Volatile
Moisture matter
32.01 27.77
40.84
45.52
30.85 27.32
39.51
44.79
30.66 28.17
40.63
44.87








Fixed
carbon
33.24
48.89
54.48
33.68
48.70
55.21
34.61
49.91
55.13









Ash S
6.98 .56
10.27 .82
.91
8.15 .62
1 1 79 .90
1.02
6.56 .43
9.46 .62
.68








Ultimate. %

H C N
6.43 43.95 .65
4.22 64.63 .96
4.70 72.03 1.07
6.22 43.89 .70
4.04 63.47 1.02
4.58 71.95 1.15
6.33 45.19 .71
4.22 65.17 1.02
4.66 71.97 1.13








Form of sulfur. %

O
41.43
19.10
21.29
40.42
18.78
21.30
40.78
19.51
21.56








Heating
value (Btu)
7240
10650
11870
7220
10440
11840
7420
10710
11820









Sulfate
.05
.07
.08
.05
.07
.08
.02
.03
.04









Pyritic Organic
.32 .18
.48 .27
.53 .30
.39 .19
.56 .27
.64 .31
.06 .34
.09 .49
.10 .54








Table 88. -Major ash constituents and fusibility of ash, Pine Hills coal deposit.





Drill hole Depth
and location sampled
PH-1C
7N 50E S29 95 to
ACAB 112 ft.
PH-2C
7N49ES13 143 to
DCDA 161 ft.
PH-3C
7N49ES11 74 to
CDDD 93 ft.





Lab. Coal
sample bed
Dominy
GF-68-
1865
Dominy
GF-68-
1862
Dominy
GF-68-
1863





AljOj
12.0


12.2


11.2







CaO FeaO3 KjO
27.4 8.3 .1


26.0 8.3 .7


34.4 5.6 .2







MgO NaaO
8.7 .5


6.7 2.4


9.7 1.3





Constituent, '

P205
.4


.3


.2

















% Fusibility of ash.°F

SiO2 SO3 TiOj
23.7 15.2 .5


25.5 15.4 .4


20.1 13.9 .4



LOI@
soorc
.1


.1


.2



Total
96.9


98.0


97.2


Initial

deformation Softening Fluid
temp. temp. temp.
2250


2250


2420


2300 2350


2300 2350


2470 2520










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-------
                                       INDIVIDUAL DEPOSITS—KNOWLTON


                  Table 89.—Reserves, overburden, overburden ratio, acres, and tons/acre, Knowlton coal deposit.
                                                                                        129
                                                  DOM1NY BED
   Thickness of
  overburden, ft.
Indicated reserves,
   million tons
Overburden and
  interburden,
 million cu. yd.
 Overburden and
 interburden ratio,
 cubic yards/ton
Acres
Tons/acre
      Oto  50
     50 to 100
    100 to 150
               Total
     219.61                 462.35
     425.86               1,723.99
     102.04                 513.15
     747.51        Total  2,699.49
                        2.10             3,471.45
                        4.04            12,918.49
                        5.02             3.223.28
                Average  3.61    Total   19,613.32
                                         63,260.8
                                         32,965.1
                                         31.656.9
                                 Average  38,112.3
   Thickness of
  overburden, ft.
Indicated reserves,
  million tons
  Overburden,
 million cu. yd.
Overburden ratio,
 cubic yards/ton
Acres
Tons/acre
      Oto  50
     50 to 100
    100 to 150
               Total
                  Total
      65.00             1.11             3,180.8
      93.56             2.48              768.0
     101.06             4.15              499.2
     259.62     Average  2.15    Total    4,448.0
                                         18,341.3
                                         49,010.4
                                         48.737.9
                                 Average  27,048.1
            KNOWLTON COAL DEPOSIT

                      LOCATION

   The Knowlton coal deposit (PI. 32A and B) is in T. 6
and 7 N., R. 53 and 54 E., Custer County, about 40 miles
east of Miles City. U.S. Highway 12 crosses the north end
of the mapped area. The coal field underlies the high di-
vide between the Powder River valley to the west and the
O'Fallon Creek valley to the east.

         FIELD WORK AND MAP PREPARATION

   All the field work resulting in the present map of the
Knowlton coal deposit was completed during the summer
of 1971. Geologic mapping on 7&-minute topographic
maps, where available, was supplemented by mapping on
black-and-white aerial photos for the rest of the area.

              PREVIOUS GEOLOGIC WORK

   The Knowlton coal deposit was originally mapped by
the U.S. Geological  Sumy. The western part of the area
was described  in the Miles  City coal report (Collier  and
Smith, 1909). The eastern part was included in the report
on the Baker lignite  field (Bowen, 1912).

                  LAND OWNERSHIP

   The Knowlton coal deposit lies  within the land grant
to Burlington Northern, Inc. The railroad, although it has
                                       conveyed  much of the surface, has  retained the coal
                                       rights. At the time of the grant, some odd-numbered sec-
                                       tions were not available, so the railroad's coal ownership
                                       in the area is not complete. The State of Montana owns
                                       surface and minerals on sec. 16 and 36 in each township.
                                       The Federal Government has conveyed most of the sur-
                                       face, but has, in general, retained the mineral rights, al-
                                       though some coal is privately owned.

                                                SURFACE FEATURES AND LAND USE

                                          The Knowlton coal deposit underlies the high divide
                                       between Powder River to the west and O'Fallon Creek to
                                       the east. The divide  is a  relatively flat,  gently rolling
                                       plateau bordered by clinker, which supports ponderosa
                                       pine. All of the streams in  the area  are intermittent and
                                       flow only during periods of heavy precipitation or spring
                                       runoff. Numerous springs in the area supply abundant
                                       water for livestock.

                                          The principal land uses in the area are livestock grazing
                                       and dry-land  farming for which the gently  rolling terrain
                                       is ideally suited. Various grains are cultivated, and hay is
                                       raised in many fields.

                                                      GEOLOGIC STRUCTURE

                                          The strata in the Knowlton coal deposit are almost
                                       horizontal, but a northwest  dip of a few feet per mile can
                                       be detected.

-------
                                            Table 90.-Pioximate analysis, forms of lulfui, and heating value, Knowlton coal deposit.
  Drill hole
 and location


 SH-7158
 7N54ES16
 BBBB

 SH-7159
 7N54tS21
 DADB
 SH-7160
 7N54ES21
 DCBB

 SH-7161
 7N 54E S29
 OCAB
SH-7162
7N541SS32
ACDD
SH-7163
6N S4E SS
CADB
SH-7164
6N 53E S2
DACA
SH-7165
7N54ES31
CAAA
 Depth
sampled
 22 to
 32ft
 51 to
 60ft.

 60 to
 71 ft.


 80 to
 88ft.
 35 to
 42ft.

 55 to
 64ft.
100 to
107 ft.

lllto
121 ft.


 90 to
 98ft.

 98 to
110 ft.

110 to
111 ft.


 42 to
 51ft.

 57 to
 67ft.
 50 to
 56ft.

 68 to
 74ft.
                                                                                                                   Form of sulfur. %
 Lab.
number
 412



 413


 414



 415



 416


 417



 418


 419



 420


 421


 422



 423


 425



 426


 427
  Coal
  bed


 Dominy
  (D


 Dominy
  (U)
Dominy
  (M)


Dominy
  (M)

  (L)
Dominy


  (L)
Dominy
  (U)
Dominy
  (M)

  (L)
Dominy
 (M)

 (L)
Form of
analysis
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
A
B
C
*
/ Moisture
36.400


38.110


38.910


37.270


37.820


35.230


34.390


37.260


42.130


39.700


37.730


37.360


34.500


39.580


35.070


Volatile
matter
25.873
40.680
46.682
25.224
40.757
45.118
25.656
41.998
45.841
27.143
43.269
46.616
26.366
42.403
47.637
27.299
42.148
45.897
27.588
42.048
46.127
24.508
39.063
45.676
23.833
41.184
45.011
24.960
41.393
45.183
24.607
39.516
47.516
26.236
41.884
46.064
28.021
42.780
49.623
24.769
40.994
45.386
25.257
38.898
45.836
Fixed
carbon
29.550
46.462
53.318
30.683
49.576
54.882
30.312
49.618
54.159
31.084
49.551
53.384
28.982
46.610
52.363
32.180
49.684
54.103
32.220
49.109
53.873
29.148
46.458
54.324
29.117
50.314
54.989
30.282
50.219
54.817
27.179
43.648
52.484
30.719
49.041
53.936
28.447
43.430
50.377
29.805
49.330
54.614
29.845
45.165
54.164

Ash
8.178
12.858

5.983
9.667

5.122
8.384

4.504
7.180

6.832
10.987

5.290
8.168

5.802
8.843

9.084
14.479

4.920
8.502

5.058
8.388

10.484
16.836

5.684
9.075

9.032
13.790

5.846
9.676

9.828
15.136


Sulfur
.684
1.076
1.235
.567
.917
1.015
.377
.617
.674
.204
.325
.350
.220
.353
.397
.606
.936
1.020
.518
.790
.866
.182
.290
.339
.299
.516
.564
.649
1.077
1.175
.564
.906
1.089
.733
1.171
1.287
.426
.650
.754
.567
.939
1.039
.325
.501
.590

Sulfate
.153
.240
.276
.029
.046
.051
.000
.000
.000
.021
.034
.036
.021
.033
.037
.015
.023.
.025
.030
.045
.049
.014
.022
.026
.006
.011
.012
.014
.022
.024
.069
.110
.133
.021
.033
.037
.014
.022
.026
.020
.034
.037
.007
.011
.013

Pyritic
.473
.744
.854
.481
.778
.861
.267
.438
.478
.042
.067
.073
.055
.088
.099
.395
.609
.663
.244
.372
.408
.035
.056
.065
.104
.179
.196
.392
.650
.710
.124
.199
.239
.426
.680
.748
.036
.055
.064
.324
.536
.594
.036
.056
.066

Organic
.058
.092
.105
.057
.093
.103
.110
.180
.196
.141
.224
.242
.144
.232
.261
.197
.305
.332
.244
.372
.408
.133
.212
.248
.188
.325
.355
.243
.404
.441
.371
.597
.717
.286
.457
.503
.375
.573
.664
.223
.369
.408
.282
.434
.511
Heating
value (Btu)
6323
9942
11408
6654
10752
11903
6479
10605
11575
6792
10828
11665
6449
10371
11651
7154
11045
12027
7271
11083
12158
6354
10128
11843
6718
11609
12688
6328
10493
11454
6297
10113
12160
6955
11104
12212
6862
10476
12152
6554
10848
12010
6497
10006
11790











CO
SB
5
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U = Upper bench of Dominy
M = Middle bench of Dominy
L = Lower bench of Dominy

-------
SH-7166A
7N 53E S36
DCDD
SH-7172
7N 54E S8
ADBB
SH-7173
7N 54E S5
DDAD

SH-7176
6N 54E S9
CBBC
SH-7177
6N54ES16
ABAC
SH-7178
6N54ES16
CBAD

SH-7178 A
6N54ES16
CDDA
110 to
118ft.

118 to
120ft.
 50 to
 58ft.

 58 to
 66ft.

 66 to
 74ft.

 91 to
 98ft.

124 to
131 ft.
 32 to
 37ft.
 60 to
 69ft.

 69 to
 71ft.
 42 to
 50ft.

 50 to
 56ft.
 60 to
 65ft.


 20 to
 30ft.

 30 to
 34 ft.
428


429



430


431


432


433


434



435



436


437



456


457



438



439


440
          Dominy
            (U)
Dominy
  (U)
                                           (M)


                                           (L)
Dominy
  (L)


Dominy
(M&L)
Dominy
(M&L)
                      Local
Dominy
(M&t)
A
B
C
A
B
C

A
B
C
A
B
C
A
B
C
A
B
C
A
B
C

A
B
C

A
B
C
A
B
C

A
B
C
A
B
C

A
B
C

A
B
C
A
36.150


40.040


38.690


38.370


38.280


39.590


38.730


34.500


36.000


34.120


36.400


36.100


38.770


37.530


36.850


24.999
39.152
43.688
22.130
36.909
40.229
25.069
40.888
44.413
24.606
39.925
43.195
26.313
42.633
45.492
24.294
40.215
43.780
24.138
39.396
42.844
24.795
37.855
44.930
25.537
39.901
46.336
27.857
42.285
48.466
25.875
40.684
45.603
25.680
40.187
47.001
24.641
40.244
44.677
25.408
40.672
45.763
26.052
41.254
46.334
32.222
50.465
56.312
32.881
54.838
59.771
31.375
51.175
55.587
32.359
52.505
56.805
31.528
51.083
54.508
31.197
51.643
56.220
32.201
52.555
57.156
30.391
46.399
55.070
29.575
46.211
53.664
29.621
44.962
51.534
30.864
48.528
54.397
28.957
45.316
52.999
30.513
49.833
55.323
30.112
48.203
54.237
30.174
47.781
53.666
6.629
10.382

4.949
8.253

4.866
7.937

4.665
7.570

3.879
6.285

4.919
8.143

4.932
8.049

10.314
15.746

8.889
13.889

8.402
12.753

6.861
10.788

9.263
14.497

6.076
9.923

6.950
11.125

6.924
10.965

.229
.359
.400
.122
.203
.222
.340
.555
.603
.199
.323
.350
.505
.819
.873
.363
.601
.654
.213
.348
.379
.201
.307
.364
.775
1.211
1.407
.185
.281
.322
.325
.510
.572
.890
1.393
1.629
.374
.610
.677
.325
.520
.585
.184
.291
.326
.007
.011
.013
.007
.011
.012
.029
.047
.051
.031
.050
.054
.090
.145
.155
.015
.026
.028
.009
.014
.015
.015
.023
.027
.037
.058
.067
.022
.034
.039
.038
.059
.067
.023
.036
.042
.028
.046
.051
.041
.066
.075
.014
.022
.025
.072
.112
.125
.020
.034
.037
.116
.189
.205
.031
.050
.054
.130
.211
.225
.139
.230
.250
.026
.042
.045
.015
.023
.027
.465
.727
.844
.007
.011
.013
.166
.261
.293
.629
.985
1.152
.000
.000
.000
.166
.265
.299
.007
.011
.013
.150
.235
.263
.095
.158
.172

.196
.319
.346
.138
.224
.242
.285
.462
.493
.208
.345
.376
.179
.292
.318

.171
.261
.310

.273
.427
.496
.156
.236
.271

.121
.190
.213
.238
.372
.435

.345
.564
.626

.117
.188
.212
.162
.257
.289
6842
10715
11957
6351
10592
11544
6785
11066
12021
6850
11115
12025
7143
11574
12350
6704
11098
12082
6681
10904
11858
6583
10050
11928
6737
10526
12224
6815
10344
11856
6793
10680
11972
6780
10610
12409
6587
10759
11944
6629
10612
11940
6671
10563
11864














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U= Upper bench of Dominy
M = Middle bench of Dominy
L = Lower bench of Dominy
I/A, as received; B, moisture free; C, moisture and ash free.
                                                                                                                                           u>

-------
Table 91.-Major ash constituents, Knowlton coal deposit.
Drill hole
and location
SH-7158
7N54ES16
BBBB
SH-7159
7N54ES21
DADB
SH-7160
7N54ES21
DCBB

SH-7161
7N 54E S29
CCAB


SH-7162
7N 54E S32
ACDD
SH-7163
6NS4ES5
CADB
SH-7164
6N 53E S2
DACA
8H-7165
7N54ES31
CAAA
Depth
sampled

22 to
32ft.

51 to
71 ft.

80 to
88ft.


35 to
42ft.
55 to
64ft.

100 to
121 ft.

90 to
lllft.

42 to
67ft,

50 to
56ft.
Lab.
sample


412


413-414


415



416

417


418-419


420-422


423,425


426
Coal
bed
Dominy
(L)

Dominy
(U)

Dominy
(M)


Dominy
(M)

(L)

Dominy
(M&L)

Dominy
(U)

Dominy
(M&L)

Dominy
(M)


Alj03
17.3


10.7


12.4



10.0


19.9

18.7


10.5


15.3


19.3



CaO
21.8


30.8


22.2



20.2


22.1

16.9


30.4


21.5


21.4



Fe20j
6.4


6.4


13.2



14.7


3.6

4.7


4.8


6.2


5.2



KjO
.2


.2


.2



.2


.2

.8


.1


.3


.5


V.
MgO
6.3


10.3


10.0



6.4


6.1

5.1


12.4


6.1


7.3


.oniuiucni, n
Na20 PjOs
.4 .1


1.1 .8


.5 .2



.8 .1


1.4 .1

1.2 .1


.7 .4


2.0 .1


A .1



SiOj
27.2


14.9-


14.4



13.2


32.6

36.5


18.5


32.4


34.0



SO3
14.9


15.2


21.4



26.5


7.0

8.7


14.3


11.3


8.5



Ti03
.6


.4


.4



.2


.4

.6


.5


.8


.8



Total
95.2


90.8


94.9



92.3


93.4

93.3


92.6


96.0


97.9





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-------
SH-7J66 A
7N 53H S36
DCDD
SH-7172
7N 54E S8
ADBB


SH-7173
7N 54h S5
DIMD
SH-7176
6N 54E S9
CBBC
SH-7I77
6N 54KS16
A IMC
SH-7178
ON 541 SI6
r MAN
SH-7178 A
6N54i;S16
(DIM
110 to
12011
50lo
74 It.
9) ro
98 ft.
124 to
131 fi.
32 to
37 ft.
60 to
71 ft.
42 to
56/t
60 to
65 ft.
20 to
34ft
428-429
430^32
433
434
435
436-U7
456-457
438
439-440
Dommy
'10
Dominy
OJ)
(Mj
fL)
Domi/iy
H.j
Uominy
rM&L^
Dommy
fM&L>
I, ota)
Donuny
fM&L;
                                                           11.2    31.2       2.3       .1       11.4
            .3       .1       31.3       7.7    .8
                                           96.4
                                                            8.9    28.7       6.6       3      10.9        1.9       .3       16.8     18.2    .3       92.9
                                                           12.5    24.9      11.7      .2       8.8        1.1       ,4       14.6     20.8    .2       95.2
                                                           18.9    22.0       4.7      .3       9.5        2.9       .3       29.4      8.2    .5
                                                           13.7     7.7       3.2
4.1
.9       .1       59.4       38     .7
                                                           15,7    21.3       8.7       .2       6.2
            .6
         1        27.8      15.5     .5
                                                           19.1     22.1       4.7       .2       9.3
                                                       96.7
94.5
96.6
                                                           17.2    20.7       71       .2       7.1        1.2       .1        28.2      14.2     6       96.6
                                                           11.4    22.0       4J       .2       6.9        19        1        36.3      11.5     .8       95.6
            .9        1       31.9       8.3    .7       97.3
                                                                                                                                                                           5
                                                                                                                                                                           O
                                                                          §
z
O
*
r
I' » Upper bench of Dormny

M » Middk bench of iJomiriy

L * Lower bench of Liorruny
                                                                                                                                                                           <*>

-------
134
STRIPPABLB COAL. SOUTHEASTERN MONTANA
                      COAL BEDS

   The coal beds in the Knowlton coal deposit that carry
economically recoverable reserves are the three benches
of the Dominy coal bed, low in the Tongue River Member
of the Fort Union Formation. The upper bench maintains
a thickness of 25 feet or more. In the northern part of
the area its base is 10 feet above the middle bench, and in
the southern part of the deposit it is 81 feet above the
combined middle and lower  benches (PI. 32B),  In the
northern part of the  deposit the middle bench is 23 feet
above the lower bench, but in the southeastern part of
 the area, these two benches join to form a single bench
 17 feet thick,  as shown in drill  hole SH-7163,  sec.  5.
 T.6N..R.54E.

   The three benches of the Dominy bed are shown in
 drill  hole SH-7172. sec. 8, T. 7 N.. R. 54 E. The upper
 bench is 28 feet thick; 11  feet below it is the middle bench,
 which  is 12 feet thick; 23 feet below that  is the lower
 bench  which is 10 feet thick. In  drill hole  SH-7166 A,
                        sec, 36,T. 7 N.. R. S3 E., the upper bench is 31 feet thick;
                        20 feet below it is the middle bench, which is 9 feet thick;
                        14 feet below that is the lower bench, which is 11 feet
                        thick. Another coal  bed below the Dominy has been
                        drilled in the southeastern corner of the deposit, in sec. 16,
                        T. 6 N., R. 54 E. In drill hole SH-7177 it is 6 feet thick,
                        and in drill hole SH-7178. it is 5 feet thick.

                                           COAL QUALITY

                           Thirty  core samples of  the benches of the Dominy
                        coal bed were taken during the 1971 core-drilling program
                        and were analyzed by the Montana Bureau of Mines and
                        Geology analytical laboratory. Proximate analysis, forms
                        of sulfur, and heating values  are shown in Table 90, and
                        major ash constituents are shown in Table 91.

                                           COAL RESERVES

                            The coal reserves in the three benches of the Dominy
                         coal  bed in the  Knowlton area  total 867,820,000 tons
                        (Table 89).
                                                REFERENCES
 AMERICAN  SOCIETY FOR TESTING  AND MATERIALS.
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                         BOWEN, C.F.. 1912. The Bakej  lignite field. Custor County,
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                         BROWN, ANDREW,  CULBERTSON, W.C., DUNHAM.  R.J..
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-------
                                                   REFERENCES
                                                                                                               135
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KEPFERLE, R.C.. 1954. Selected deposits of strippable coal in
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   Supplement for 1951 through 1960, Montana.

WARREN. W.C..  1959. Reconnaissance geology of the Bimey-
   Broadus coal  field.  Rosebud and Powder  River Counties,
   Montana: US. Geol. Survey Bull. 1072-J. p. 561-585.

WEGEMANN, C-H., 1910,  Notes on the coal of the Custer Na-
   tional  Forest. Montana: US.Geol. Survey Bull. 381-A.p. 108-
   114.

WYOMING GEOLOGICAL ASSOCIATION. 1%5. Geologic his-
   tory of Powder River Basin: Am. Assoc.  Petroleum Geologists
   Bull. 49. p. 1893-1907,24 fig.

-------
                                   TECHNICAL REPORT DATA
                            (Please read Instructions on the reverse before completing)
i. R
      !-4!?0/3-74-033
                             2.
                                                           3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
 Quality and Reserves of SMppable Coal, Selected
 Deposits,  Southeastern Montana
                            5. REPORT DATE
                              December. 1973
                            6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)

  Robert  E.  Matson and John W.  Blumer
                                                           8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS

 Montana  Bureau of Mines  and Geology
 Butte, Montana
                                                           10. PROGRAM ELEMENT NO.
                            11. CONTRACT/GRANT NO.
                                                              S 800 900
12. SPONSORING AGENCY NAME AND ADDRESS
 EPA-401  M.Street, SW, Washington, D. C.  20460
 State  of Montana, Helena,  Montana  59601
                            13. TYPE OF REPORT AND PERIOD COVERED

                              June  1969 to December  1973
                            14. SPONSORING AGENCY CODE
16. SUPPLEMENTARY NOTES
16. ABSTRACT
 Quality and quantity of strippable subbituminous  and lignite coal  1n  32 deposits
 are described, and coal distribution is shown  on  46 plates.  All of the coal is
 classified as low in sulfur  except the Sweeney Creek-Snyder Creek  coal  deposit;
 its reported sulfur content  exceeds 1% in four core samples.  Total strfppable
 reserves are 32 billion tons on 770,000 acres.

 Proximate analyses, forms  of sulfur, calorific values, and major ash  constituents
 of the  coal samples are tabulated.

 The report includes the results of Montana Bureau of Mines and Geology  projects
 in cooperation with Burlington Northern, Inc., and with the Office of Fuel
 Resources, Environmental Protection Agency, supported by special appropriations
 by the  Legislature.
17.
                                KEY WORDS AND DOCUMENT ANALYSIS
                  DESCRIPTORS
              b.lDENTIFIERS/OPEN ENDED TERMS  C. COSATI Field/Group
 Coal  Deposits
 NT Subbituminous
 NT Lignite
0807
 Low Sulfur
Strippable
0807
Coal Deposits
18. DISTRIBUTION STATEMENT
 Release  Unlimited
                                              19. SECURITY CLASS (This Report/
                                              	Unclassified
                                          21. NO. OF PAGES
                                           142+46 plates
               20. SECURITY CLASS (Thispage)

                   Unclassified
                                                                         22. PRICE
EPA Form 2220-1 (9-73)

-------
                                                        INSTRUCTIONS

   1.    REPORT NUMBER
        Insert the EPA report number as it appears on the cover of the publication.

   2.    LEAVE BLANK

   3.    RECIPIENTS ACCESSION NUMBER
        Reserved for use by each report recipient.

   4.    TITLE AND SUBTITLE                                                                             . ,  .r
        Title should indicate clearly and briefly the subject coverage of the report, and be displayed prominently. Set subtitle, if used, in smaller
        type or otherwise subordinate it to main title. When a report is prepared in more than one volume, repeat the primary title, add volume
        number and include subtitle for the specific title.

   5.    REPORT DATE
        Each report shall carry a date indicating at least month and year. Indicate the basis on which it was selected (e.g., date of issue, date of
        approval, date of preparation, etc.).

   6.    PERFORMING ORGANIZATION CODE
        Leave blank.

   7.    AUTHOR(S)
        Give name(s) in conventional order (John R. Doe, J. Robert Doe, etc.).  List author's affiliation if it differs from the performing organi-
        zation.

   8.    PERFORMING pRGANIZATION REPORT NUMBER
        Insert if performing organization wishes to assign this number.

   9.   PERFORMING ORGANIZATION NAME AND ADDRESS
        Give name, street, city, state, and ZIP code.  List no more than two levels of an organizational hirearchy.

   10.  PROGRAM ELEMENT NUMBER
        Use the program element number under which the report was prepared. Subordinate numbers may be included in parentheses.

   11.  CONTRACT/GRANT NUMBER
        Insert contract or grant number under which report was prepared.

   12.  SPONSORING AGENCY NAME AND ADDRESS
        Include ZIP code.

   13.  TYPE OF REPORT AND PERIOD COVERED
        Indicate interim final, etc., and if applicable, dates covered.
                                     (•
   14.  SPONSORING AGENCY CODE
        Leave blank.

   15.  SUPPLEMENTARY NOTES
        Enter information not included elsewhere but useful, such as: Prepared in cooperation with, Translation of, Presented at conference of,
        To be published in, Supersedes, Supplements, etc.

   16.  ABSTRACT
        Include a brief (200 words or less) factual summary of the most significant information contained in the report. If the report contains a
        significant bibliography or literature survey, mention it here.

    17.  KEY WORDS AND DOCUMENT ANALYSIS
        (a) DESCRIPTORS - Select from the Thesaurus of Engineering and Scientific Terms the proper authorized terms that identify the major
        concept of the research and are sufficiently specific and precise to be used as index entries for cataloging.

        (b) IDENTIFIERS AND OPEN-ENDED TERMS - Use identifiers for project names, code names, equipment designators, etc. Use open-
        ended terms written in descriptor form for those subjects for which no descriptor exists.

        (c) COSATI FIELD GROUP - Field and group assignments are to be taken from the 1965 COSATI Subject Category List. Since the ma-
        jority of documents are multidisciplinary in nature, the Primary Field/Group assignment(s) will be specific discipline, area of human
        endeavor, or type of physical object. The application(s) will be cross-referenced with secondary Field/Group assignments that will follow
        the primary posting(s).

   18.  DISTRIBUTION STATEMENT
        Denote releasability to the public or limitation for reasons other than security for example "Release Unlimited."  Cite any availability to
        the public, with address and price. /

   19. &20. SECURITY CLASSIFICATION
        DO NOT submit classified reports to the National Technical Information service.

   21.  NUMBER OF PAGES
        Insert the total number of pages, including this one and unnumbered pages, but exclude distribution list, if any.

   22.  PRICE
        Insert the price set by the National Technical Information Service or the Government Printing Office, if known.
EPA Form 2220-1 (9-73) (Reverse)

-------
   THE MONTANA BUREAU OF MINES AND GEOLOGY IS A
PUBLIC SERVICE AGENCY FOR THE STATE OF MONTANA.
ITS PURPOSE IS TO ASSIST IN DEVELOPING  THE STATE'S
MINERAL RESOURCES. IT CONDUCTS FIELD STUDIES  OF
MONTANA GEOLOGY AND MINERAL DEPOSITS, INCLUDING
METALS, OIL AND GAS, COAL, OTHER NON-METALLIC MIN-
ERALS, AND GROUND-WATER. IT ALSO CARRIES OUT RE-
SEARCH IN MINERAL BENEFICIATION, EXTRACTIVE METAL-
LURGY, AND ECONOMIC PROBLEMS CONNECTED WITH THE
MINERAL INDUSTRY IN MONTANA. THE RESULTS OF THESE
STUDIES ARE PUBLISHED IN REPORTS SUCH  AS THIS.

   FOR FURTHER INFORMATICN, ADDRESS THE DIRECTOR,
MONTANA BUREAU OF MINES AND GEOLOGY, MONTANA
COLLEGE OF MINERAL SCIENCE AND TECHNOLOGY, BUTTE.

-------
PAGE NOT
AVAILABLE
DIGITALLY

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MONTANA  BUREAU OF  MINES  AND GEOLOGY
                                    R. 44 E.
                                                                        BULLETIN  91     PLATE  8


                                                                            EXPLANATION
                                                                                                      50 - strippable Anderson coal bed
                                                                                                4012   altitude at- top of collar

                                                                                                31'013920' altitude at top of 31' of coa

                                                                                                T. D. 130' total depth of drill hole
                                                                                                  Anderson and Dietz beds converge
                           SH-7038
                           3669'
                           31'at 3637'
                           5' at 3582'
                           T, D. 105'
                                                                                  3920
                                                                     • I     -^. ' • . T. D. 130' '
                                                                                                                     R. 45 E.
     iap from U.S.G.S. 7 '/2 minute topographic maps: Poker Jim Butte,
   Jrowns Mtn., Fort Howes, and Birney 4 NW.
        N
                                 MAP OF

         POKER   JIM   LOOKOUT  COAL  DEPOSIT
                                 SHOWING

STRIPPABLE  RESERVES  IN THE ANDERSON  AND  DIETZ  COAL BEDS,
         ROSEBUD  AND POWDER RIVER  COUNTIES,  MONTANA
Project Chief - R. E. Motson
Geologist  -W. A. Van Voast
Draftsmen  -E, A, Woods
                                                        DATUM IS MEAN SEA LEVEL

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MONTANA  BUREAU  OF MINES  AND  GEOLOGY
                                                                                                                              BULLETIN  91      PLATE   IIA
                                                                                         POKER   JIM  CREEK-O'DELL   CREEK   COAL  DEPOSIT
                                                                                                   STRIPPABLE  RESERVES  IN  THE KNOBLOCH  COAL  BED,
                                                                                                               ROSEBUD  COUNTY, MONTANA
                                                                                                                                   •     M U.-.M G   drill  hole

                                                                                                                                 SH-II7   hole  designation

                                                                                                                                 3143'     altitude  at top  of collar

                                                                                                                                 8'at 3085' altitude  at top  of 8'  of coal

                                                                                                                                 20'at 3044' altitude  at top  of 20' of  coal

                                                                                                                                 T. D. ISO1 total depth of  hole

                                                                                                                                 	- n       Parting  information

                                                                                                                                              opach of  coal  bed

                                                                                                                                             Overburden  of upper  bench

                                                                                                                                  -'-^-- —--~^v Overburden  of middle  bench
                                                                                                                                          *~  Line of cross section (plate 34)
                                                                                                                                         B.L.
                             Base map from advance topographic
                             7 1/2 min. quadrangle maps:
                             Birney Day School, Green Creek,
                             Birney, Brown Mountain
Project Chief -  R.E, Matsor
Geologist   -  O.W.Blume
Draftsman   -  E.A. flood:

-------
 MONTANA  BUREAU OF  MINES  AND  GEOLOGY
                              MAP  OF

   POKER JIM  CREEK-O'DELL  CREEK  COAL DEPOSIT

                              SHOWING

 STRIPPABLE  RESERVES  IN  THE KNOBLOCH COAL BED,
 ROSEBUD AND  POWDER  RIVER COUNTIES,  MONTANA
                     Datum is mean sea  leve
L,    BULLETIN   91        PLATE  II  B

              R.44 E.I R.45E,
                                                                                                                                    PO.
Base from advance topographic quadrangle map
Ashland, Green Creek, Willow Crossing, and King M<
                                                                                                                                                                  0- 50' overburden


                                                                                                                                                                 50-iOO' overburden


                                                                                                                                                                 100'--150' overburden

                                                                                                                                                                 I50L200' overburden


                                                                                                                                                                200L250' overburden
           »    M.B.M.G drill hole
        SH-7059  hole designation
        3228'    oltitudp at top of collar
        i4+at'3u3b' altitude at top of 14'of coal
        T.D. 206'  totol depth of hole


           O    Wafer well  drill hole
         22abd


       • -n'li" n	Parting information


     40'	Isopach of  coal bed


        BL
    	•*-    Line  of cross  section
                 (plate 34)


    project Chief -  R. E. Motson
    Geologist    -  J. W, Blumer
    Oraftsmon   -  E.A. Woods

-------
   MONTANA BUREAU  OF  MINES AND GEOLOGY
                                                                                                                                       BULLETIN   91    PLATE  2
                                                                                                                                MAP  OF

                                                                                                      DEER   CREEK   COAL   DEPOSIT
                                                                                                                                SHOWING
                                                                                                  STRIPPABLE   RESERVES   IN  THE  ANDERSON ,  DIETZ  No. I
                                                                                                  AND DIETZ No.2 COAL   BEDS, BIG HORN COUNTY, MONTANA
                                                   -BMC-721
                                                   P3765
                                                    8'  at 3682
                                                    26'at 3418
                                                    25'at 3290
                                                    T. D. 600'
                                                                                                                        E XPLANATION

                                                                                                                  Dietz No. I  coal bed

                                                                                                                   0-50'   of  overburden
                                                                          Anderson  coat  bed

                                                                          0-50'    of overburden
                                                                      Diefz  No. 2 coal  bed

                                                                        0-50'   of  overbuden
                                                                                                             M.B.M.G.  drill hole

                                                                                                  BMC- 721    hole designation
                                                                                                  3765'       altitude at top of  collar
                                                                                                  25' at 3290'  altitude at lop of 25'of coo

                                                                                                  T. D.  600'   total depth of drill hole
SH-7020
3480'
13' at 3284'
24' at 3186'
T D. 350'
Clinker, not shown where under-
ain by another  strippable coal bed
                                                           sopach of thickness, of  Anderson
                                                           Coal Bed.
                                   'SH-TOI
                                    3640'
                                    ISat 333,2^
                                    TD 338
                                                           sopach of parting to next low
                                                           ;oal bed-
                                                                                     _. "ft „     Oil well  drill  hole
                                                                                     Shell-Gov.
                                                                        Fault, dashed where infe
Base,map from US-G-S 7 72 min. topographic
quads'  Decker and Holmei Ranch.
                                    MONTANA
                                    WYOMING
                                                                                            Line  of cross section ( plate 33}
  Law, B. E.,and Srazls, S. L.,preliminary geologic

Big Horn County, Montana. (1972)
  Map of the northern extension  of the Sherldon
Coal  Field ,  Rosebud and Big Horn Counties,
Montana, U.S.G.S. Bull. 606.


       Project   Chief -  R. E. Matson
       Geologist       -  J. W. Blumer
        Draftsman     -  E. A. Woods

-------
     MONTANA   BUREAU  OF  MINES  AND  GEOLOGY
                              MAP  OF

        FIRE    GULCH   COAL    DEPOSIT
                             SHOWING

  STRIPPABLE  RESERVES  IN  THE COOK  AND  PAWNEE
   COAL   BEDS, POWDER   RIVER  COUNTY,   MONTANA
                        DATUM IS MEAN SEA LEVEL
                     EXPLANATION
	~——  Cook cool bed

L v "., 1  Clinker
                                                                                                                                                       BULLETIN   91      PLATE   21
                                                                                                                                                                               R.49E.
         0-50'   of   overburden


         50'-100' "


         I00'-!50' "      "


         150'- 200' "
      •        M. B. M. G  drill hole
   SH-7134      hole designdtion
   3978'        altitude dt top of colldr
   38' ot 3723'   altitude ot top of 38' of coal
   T. D. 400'     total depth of drill  hole
                                                                                   SH-7I2I
                                                                                   4051'
                                                                                   7'at396l'
                                                                                   22'at 3750'
                                                                                   12'at 37(6'
                                                                                   T.D.380'
	Pawnee coal bed

         Clinker


         0-50'   of  overburden


         50'-100'  "


         100'-ISO'  "
                          SH-7134
                          3978'
                          I2'at3924'
                          22'at3724'
                          14'at 3699
                          5lat 3583
                          I D. 400
                               map from U.S.G.S. 7'/2 minute topographic auodrangle maps: Hodsdon Flats,     R. 48 E.
                                                     of Powder River County, M
                                                                                                                                                                                R.49E.
                                                                                                                                               Thickness of the  parting between the two benches
                                                                                                                                                of the Cook coal bed.
                                                                                                                                               Isopoch of the upper bench of the Cook cool bed
                                                                                                                                )0	Isopach of  the  lower bench  of the Cook coal  bed.
                                                                                                                               Clinker and  outcrop  mapped  by J. W Blumer, from colored  and black-and-
                                                                                                                               white, aerial  photographs.

-------
MONTANA BUREAU  OF MINES  AND  GEOLOGY

                                   R.47E.
 T._4S.
 T. 53
                                    BULLETIN  91     PLATE 25 B

                         MAP OF

      SONNETTE   COAL   DEPOSIT

                         SHOWING

STRIPPABLE  RESERVES  IN THE COOK  COAL  BED,
        POWDER  RIVER COUNTY,  MONTANA
                                                                                       DATUM IS MEAN SEA LEVEL
                                                                                                    EXPLANATION

                                                                                                          •       M. B. M.G. drill hole

                                                                                                          SH-7II7    hole designation

                                                                                                          3924'     altitude at top of collar


                                                                                                          I0'a13853'   altitude at top of 10' of cool

                                                                                                          T. D. 220'   total depth of drill hole
                                                                                   Clinker and outcrop mapped by J. W.
                                                                                   Blumer from aerial photographs.
                                                                                                                   SH-7II8
                                                                                                                   4066'
                                                                                                                   7!at40Z9' (Canyon)
                                                                                                                   10'at 3988' (Cook)
                                                                                                                   T. D, 100'
                            Project Chief- R. E Matson
                            Geologist  - 0 W. Blumer
                            Draftsman - E A Woods
  Base map from U.S.G.S.  7 !/2 minute topographic maps
    Threemile Buttes and Sonnette.

-------
MONTANA BUREAU OF MINES  AND  GEOLOGY
                    R. 46 E R.47 E.
                                   BULLETIN  91    PLATE  26
                              MAP OF
       HOME  CREEK  BUTTE  COAL  DEPOSIT
                              SHOWING
STRIPPABLE  RESERVES IN  THE  FERRY  AND  CANYON
   COAL  BEDS,  POWDER RIVER  COUNTY, MONTANA
                                                                                           EXPLANATION
                                                                                                     •        M.B.M.G. drill hole
                                                                                                     SH-7154   hole  designation
                                                                                                     4133'     altitude at top of collar
                                                                                                     I0'at4ll2'  altitude at top of 10'of coal

                                                                                                     T.D. 156'  total depth of drill  hole
                                                                                                      •0-       Oil well drill hole
                                                                                                      N.P.R.R No I
                                                                                                         Line of cross section (plate 34)
                                                                                                    !  Clinker and outcrop mapped  by J. W. Blumer
                                                                                                      and M. L.Granberg from aerial photographs.
      Canyon coal bed

      O-IOO1 of overburden

      Ferry coal bed
      0-501   of overburden

      50'-IOO'  "    "

      100-150'  'I    »

      100'-outcrop of Canyon coal bed
I                                                                                                      Project Chief  -R.E.Motson
                                                                                                      Geologists   -J. W. Blumer
  ie map from U.S G.S. 7 '/2-minuti
  topographic maps! Home Creek Bui
  ind Colemon  Draw.
                                                                                                         SH-7154
                                                                                                         4133'
                                                                                                         10'0)4112
                                                                                                         24'at
                                                                                                                             "-PC

-------
 MONTANA  BUREAU  OF MINES  AND GEOLOGY
                       Vertical scale               Horizontal scale

                   0'       40'       80'       0'      4000'     8000'
                 1
Upper   Knobloch



Lower   Knobloch
                                                                                                                                           BULLETIN    91     PLATE  28
                                                                                                            MAP OF

                                                                                           SAND  CREEK COAL  DEPOSIT

                                                                                                            SHOWING

                                                                            STRIPPABLE  RESERVES  IN THE  KNOBLOCH  COAL  BED
                                                                               CUSTER AND  POWDER RIVER  COUNTIES, MONTANA
DATUM  IS MEAN SEA  LEVEL
                                                                                                       EXPLANATION

                                                                                   Upper Knobkch  coal bed	

                                                                                   Lower Knobloch coal bed	
                                                                                                                      Clinker


                                                                                                                      0-50'  of  overburden


                                                                                                             /.'.'. •']  50'-100'  »     i.


                                                                                                                      lOO'-ISO' •'


                                                                                                                      Cooperalive drill hole  (1967)
                                                                                                        Note:  South of  10' isopach line, overburden limits  are  for the
                                                                                                              Lower Knobloch  coal bed.
                                                                                                              Norih of  10' isopach line the  Upper and  Lower  Knobloch
                                                                                                              coal beds are treated  as  one bed
                                                                                                         SC-2        hole  designation

                                                                                                         3498'        altitude at top of collar

                                                                                                         O1 at 3390'   altitude at lop  of 10' o1

                                                                                                         T. D.  I40'     total  depth of  drill hole
                                                                                                             Isopach  of parting  between  Upper and Lowe
                                                                                                               Knobloch coal beds,

    SC-3
    3414'
S   ?' at 3372'
    8'at 3363'
    8' at 3353
    14' at 3332
    T D. 97'
   Photogeologic  mapping, topographic  control, and  drilling
program conducted  under a  cooperative  agreement  betweer
the  Montana Bureau of  Mines and  Geolrjgy  and  the
Burlington Northern Incorporated, summer  1967,
         By'- L. A. Williams ,
             R E Matson  and
             T- E. Finch  ,  M. B. M.G
             Draftsman-  E- A. Woods

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MONTANA  BUREAU  OF  MINES  AND GEOLOGY
                                                                                                                   BULLETIN  91     PLATE 30
                                                                           R.42E.  R.43E.
                      EXPLANATION
Sawyer coal bed
V .4 <. v
,<: ..i_s
                             »       M. B. M.G. drill hole


                             SH-7097   hole designation


                             3470'     altitude  at top of collar


                             I0'at3396'  altitude  at top of 10' of coal


                             T. D. 126'   total depth of drill hole
Knobloch coal bed

      Clinker
                              -0-      Oil well drill  hole
                             Wolf No. 1-5
      0-50   of overburden


      50-100'


      lOO'-ISO1  M    n


Rosebud coal bed (average thickness 15')
                                     Fault, dashed where inferred
                            Clinker and outcrop mapped by
                            L. J Maki  from aerial photographs
                                                                                                                       SH-7097
                                                                                                                       3470'  '
                                                                                                                       I0'at339<
                                                                                                                       T. D. 126' "•
                                                                                                                      \3470' -J -i
                                                                                                                       I0'at3396' *
                                                                                                 RESERVATION
     NORTHERN                    CHEYENNE
  •ase map from U.S.G.S. 7 '/2-minute topographic maps: Ashland,
    Garfield Peak, Badger Peak , Lee 2 SW, and Lee 2 SE
                                                                 MAP OF
     tii
                           GREENLEAF  CREEK-MILLER   CREEK    COAL   DEPOSIT
                                                                SHOWING

                          STRiPPABLE   RESERVES   IN  THE  SAWYER, KNOBLOCH,  AND  ROSEBUD
                                            COAL  BEDS,ROSEBUD  COUNTY,  MONTANA
 BOUNDARY

Project Chief -R.E.Maison
Geologist   -L. J. Maki
Draftsman  - E. A. Woods
                                                             DATUM IS MEAN SEA LEVEL

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MONTANA  BUREAU  OF  MINES  AND  GEOLOGY

                            MAP OF


               KNOWLTON  COAL  DEPOSIT

                            SHOWING

 STRIPPABLE RESERVES  IN THE UPPER  DOMINY COAL BED,
                 CUSTER  COUNTY,  MONTANA
                                                                                                                                        BULLETIN   91
                                                                                                                                                             PLATE   32 B
                     DATUM IS MtAN StA LtVbL


                        EXPLANATION
           0-50    of overburden


           50'-IOO'   i'


           100'-150'  "


  	Upper  Dominy coal bed
   •     M.B.M.G.  drill ho

SH-7166   hole designation

3377'     altitude  at top of collar

29'at324l' altitude  at top of 29' of  coal

TO. 2001  total  depth of  drill hole
                                                                                                                                                         Andrau
                                                                                                                                                        No. 1-14 N.P.R.R
                                                                                                                         SH-7159
                                                                                                                         3305'
                                                                                                                         25'at 3254
                                                                                                                         T.D. 155'
                                                             Eastern limit of
                                                             opographic  contro
                Andrau
              Anderson No. I
                  O-
                                                         SH-7166
                                                         3377'
                                                         29'at324l
                                                             200'
                                                                         Average  thickness
                                                                            27 '/? feet
                                              V 3lat32l9
                                             t^ 9' at 3168
                                                  0(3145
                                                T. D. 220'
                   R. 53 E
     map from  U.S.G.S. 7'/2-minute advance  topographic
      Montana Highway map  of Custer Co., Montana (Sheet
                                                                                                                 R.  54 E.
                                                                                                                        Project Chief - R.E.Matson
                                                                                                                        Geologist    -J.W.E
                                                                                                                        Draftsman   -E.A.Woods

-------
MONTANA   BUREAU  OF  MINES   AND  GEOLOGY
                                                                      R.  39 E
                  BULLETIN   91    PLATE   4


                    MAP OF

SQUIRREL  CREEK  COAL  DEPOSIT

                    SHOWING

 STRIPPABLE  RESERVES IN THE ROLAND
 COAL BED, BIG HORN COUNTY, MONTANA
                            BMC-726
                            4334'
                            8'at4299'
                            I6'at4079
                            27 at403!
                            43'at 3886'
                            T.D. 515'
                                                                          SH-7033
                                                                          4129'
                                                                          13'at 4093'
    Roland coal bed      •    M.B.M.G. drill hole

                   SH-7033 Tiole designation

  -i| Clinker            4129'  altitude  at top of collar

                   13'dt 4093' altitude  at top of 13' of coa
                                                                                                                   0-50'  overburden

                                                                                                                   50-100'    "


                                                                                                             :::•":•':•'::l ioo'-i50'
                   I. D. 80   total depth of drill hole


                            Water well drill hole

                     Carter
                                                                                                              ne  of cross section
                                                                                                            (plate 33)
                                                                                                                                       Project  Chief - R. E. Matson
                                                                                                                                       Geologists   - J. W. Blumer
                                                                                                                                                  M. L. Gronberg
                                                                                                                                       Draftsman   -M. J. Daniels

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r
MONTANA   BUREAU  OF  MINES  AND  GEOLOGY
 jjpRTHERN	[ ^CHEYENNE	INDIAN	   RESERVATION
                                                                                              BOUNDARY
                                BULLETIN 91    PLATE   5 B

                  MAP OF

KIRBY    COAL   DEPOSIT
                                                                                                                                                         SHOWING
                                                                                                                              STRIPPABLE  RESERVES  IN  THE  DIETZ   COAL  BEDS,
                                                                                                                                            BIG  HORN  COUNTY,  MONTANA
                                                                                                                                                    DATUM IS MEAN SEA LEVEL
                                                                                                                                                                  EXPLANATION
                                                                                                                                             	Outcrop of coal beds, dashed where
                                                                                                                                                   inferred,

                                                                                                                                         Upper or combined benches


                                                                                                                                          <1l >j^j|  Clinker


                                                                                                                                                 0-50'    of overburden


                                                                                                                                                 50'-100'


                                                                                                                                                 100'-150'


                                                                                                                                                 I50'-200'  "     "


                                                                                                                                                 200-250'  ><     "
                                    •      M.B.M.G.  drill hole
                                    SH-722   hole designation
                                    4493'    altitude  at top of collar
                                    25'at 4388' altitude  at top of 25' of co
                                    T. D. 240' total depth of drill hole
                                    ©_ _  ,   Private  drill hole
                                     t-o- I


                                    ®WW     Water well drill hole




                                    ^Cabot   Oil wel1  dri" hole
                                                                                                                                                                               Line of cross section (plate 33)'
                                                                                                                                                                            25:
                                                                                                                                                                              Isopach of coal bed
                                                                                                                                                                              Fault, dashed and dotted where inferred
                                                                                                                                                                                       Project Chief - R.E. Malson
                                                                                                                                                                                       Geologists  -L. J. Maki
                                                                                                                                                                                               - M. Garverich
                                                                                                                                                                                               -Van Heare .
                                                                                                                                                                                       Draftsman  -E. A. Woods !
    Kirby, Taintor Desert, Half Moon Hill, and Tongue River Oam.
                                                                                                                                                   R. 40 E.

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