JANUARY 1977
908-4-77-001
LLUVIAL VALLEY FLOORSI
IN EAST - CENTRAL
MONTANA
AND THEIR RELATION
TO STRIPPARLE
COAL RESERVES
A RECONNAISSANCE REPORT
MONTANA
ENVIRONMENTAL PROTECTION AGENCY
ROCKY MOUNTAIN PRAIRIE REGION
REGION VIII
IN COOPERATION WITH THE STATE OF MONTANA
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ALLUVIAL VALLEY FLOORS IN EAST-CENTRAL
MONTANA AND THEIR RELATION TO
STRIPPABLE COAL RESERVES
RECONNAISSANCE REPORT
JACK SCHMIDT
CONSULTANT TO:
THE MONTANA ENERGY ADVISORY COUNCIL
AND ENVIRONMENTAL SCIENCES DIVISION
MONTANA DEPARTMENT OF HEALTH & ENVIRONMENTAL SCIENCES
HELENA, MONTANA 59601
SUPPORTED BY:
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF ENERGY ACTIVITIES
1860 LINCOLN ST.
DENVER, COLORADO 80295
JANUARY, 1977
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ABSTRACT
This reconnaissance study indicates that small percentages of
strippable coal underlie the valley floors of east central Montana.
Extensive coal reserves underlie upland areas and small tributary
streams. Valley floors serve an important role in the local economy
and are the most productive lands of the region. They are primarily
high-quality sources of range forage and secondarily produce harvest-
able hay crops.
This work supports conclusions of previous investigators in de-
monstrating that the quasi land use category of alluvial valley floors
can be mapped by combining topographic maps, selected aerial photo-
graphy, and reconnaisance field work. This work identifies the al-
luvial valley floor as a part of a larger mappable geologic unit which
includes the alluvial deposits extending out from the alluvial valley
floors and likely important to those alluvial valley floors by virtue
of hydro!ogic interdependence. Included within these "related allu-
vial deposits" are "wildlife areas" which extend upstream from mapped
alluvial valley floors.
Various characteristics of valley floor areas were mapped and
vegetation was investigated along several transects in the Burns
Creek-Thirteenmile Creek KCLA and in the Redwater River area. These
data show that valley floors support distinctive vegetative communi-
ties (species lists are included in the report) and produce the most
forage of any range sites in the area. Soil salinity is the most
important factor limiting use of valley floors, particularly in
McCone and eastern Garfield Counties, and also may pose a significant
challenge to reclamation.
Stream channels, floodplains, and low terraces were mapped as
alluvial valley floors in those valleys used for hay production or
which appeared to have the potential for such use. Alluvial valley
floors overlie 1.5 percent of the tonnage of high potential develop-
ment coal reserves of the Burns Creek-Thirteenmile Creek Known Coal
Leasing Area (KCLA), Dawson and Richland Counties; 2.4 percent of the
tonnage of the Weldon-Timber Creek strippable coal deposit, western
McCone County; and 8 percent of the tonnage of the Redwater River
strippable coal deposit, eastern McCone County. Mapping of the more
extensive high terraces along alluvial valley floors in the Burns
Creek-Thirteenmile Creek KCLA and the Redwater River deposit show that
about twice as much coal underlies the total alluvial deposit area
than underlies the more restrictively defined alluvial valley floor.
If mining were excluded in the total alluvial valley floor area, an
even greater percentage of reserves would be made unavailable because
of the impracticality of developing logical mining units. Despite
this fact, extensive strippable coal reserves exist outside of
valley floor areas in each area studied in this report.
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While it remains evident that more detailed hydrologic, geologic, and en-
gineering work is necessary to identify the specific impacts of a mining opera-
tion on a particular valley floor, this effort shows that it is possible to use
reconnaissance methods to identify and map those valley floors of agricultural
and hydrologic significance. Future reconnaissance mapping efforts should focus
on valleys used in part for hay production since most all alluvial valley floors
mapped in this study contain some areas of hay production. It is estimated that
25 percent of all mapped alluvial valley floors were in hay production at the
time of the field investigations. Those areas mapped as related alluvial deoo
sits included most of the remaining hay lands. H
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TABLE OF CONTENTS
Page
Abstract 1
List of Tables v-
List of Figures v1' •
List of Plates viil.
Introduction 1
Previous Work 4
Method of Investigation 8
Mapping Unit Definitions and Application 12
Coal Data 16
Physiographic Description of Study Areas 17
Estimates of Area Involved and Coal Resource 18
Underlying Alluvial Valley Floors
Valley Floor Characteristics Identified 28
Vegetation 29
Saline Areas 35
Gravel Areas 35
Hayed Lands 35
Property Value 37
Conclusions 38
Acknowledgements 40
Bibliography 41
Appendices
Area 1. Burns Creek-Thirteenmile Creek KCLA A-l
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TABLE OF CONTENTS (continued)
Page
Area 2. Wei don-Timber Creek Deposit A-40
Area 3. Redwater River Deposit A-51
Area 4. Eastern Garfield County A-70
Common and Scientific Names of Vegetation A-77
Found in Study Area
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TABLES
Page
1 . Study Areas and Locations ....................................... 7
2. Sources of Air Photos Used for Mapping ... ........................ ^
3. Tons of Coal Underlying Alluvial Valley Floors
and Related Alluvial Deposits - Burns Creek -
Thirteenmile Creek KCLA .....^ .................................... 21
4. Area of Alluvial Valley Floors and Related Alluvial
Deposits Overlying Coal Reserves - Burns Creek -
Thirteenmile Creek KCLA ...-..- .................................... 22
5. Area of and Coal Tonnaqe Underlying Alluvial Valley Floors -
Wei don-Timber Creek Deposit , .. .................................... 24
6. Area of and Coal Tonnaqe Underlying Alluvial Valley Floors
and Related Alluvial Deposits - Redwater River Deposit
7. Summary of plant coverage data for partially to quite
saline alluvial terraces near Nelson Creek, McCone
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LIST OF FIGURES
1 . Locations of Study Area
2. Study Area Showing General Location of Alluvial Valley
Floors and Indicating Location of More Detailed Maps a
3. Location of Alluvial Valley Floors and Related Features -
Clay Butte Quadrangle, MT A"'3
4. Location of Alluvial Valley Floors and Related Features -
Bloomfield Quadrangle, MT A~4
5. Location of Alluvial Valley Floors and Related Features -
Enid SE Quadrangle, MT A'5
6. Location of Alluvial Valley Floors and Related Features -
Red Top Quadrangle, MT A-6
7. Location of Alluvial Valley Floors and Related Features -
Butler Table Quadrangle, MT A-7
8. Location of Alluvial Valley Floors and Related Features -
Intake NW Quadrangle, MT A-8
9. Location of Alluvial Valley Floors and Related Features -
McCone Heights Quadrangle A-9
10. Location of Alluvial Valley Floors and Related Features -
Allard Ranch Quadrangle, MT A-10
11. Location of Alluvial Valley Floors and Related Features -
Larson School Quadrangle, MT A-ll
12. Location of Alluvial Valley Floors and Related Features -
Knife River Mine Quadrangle, MT A-12
13. Location of Alluvial Valley Floors and Related Features -
Crane Quadrangle, MT A-13
14. Location of Alluvial Valley Floors and Related Features -
Hedstrom Lake NW and Hedstrom Lake Quadrangles, MT A-73
15. Location of Alluvial Valley Floors and Related Features -
Tree Coulee School and Hedstrom Lake SE Quadrangles, MT A-74
16. Location of Alluvial Valley Floors and Related Features -
Little Chalk Butte and Crow Rock Quadrangles, MT A-75
17. Location of Alluvial Valley Floors and Related Features -
Rock Springs School and Crow Rock SE Quadrangles, MT A-76
18. Transect A-A1 South Fork Burns Creek A-28
(Location shown on Plate 25, Intake NW)
19. Transect B-B' Middle Fork Burns Creek A-29
(Location shown on Plate 27, Allard Ranch)
20. Transect C-C1 North Fork Burns Creek A-30
(Location shown on Plate 26, McCone Heights)
21. Transect D-D' North Fork Burns Creek A-31
(Location shown on Plate 24, Butler Table)
22. Transect E-E1 North Fork Burns Creek A-32
(location shown on Plate 24, Butler Table)
23. Transect F-F1 Middle Fork Burns Creek A-33
(Location shown on Plate 22, Enid SE)
24. Transect G-G1 North Fork Thirteenmile Creek A-34
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LIST OF FIGURES (continued)
(Location shown on Plate 20, Clay Butte)
25. Transect H-H1 North Fork Thirteenmile Creek A-35
(Location shown on Plate 20, Clay Butte)
26. Transect I-I' South Fork Burns Creek A-36
(Location shown on Plate 22, Enid SE)
27. Transect J-J' Crane Creek A-37
(Location shown on Plate 28, Larson School)
28. Transect K'K' Dunlap Creek A-38
(Location shown on Plate 30, Crane)
29. Transect L-L1 Sears Creek A-39
(Location shown on Plate 30, Crane)
30. Transect M-M' Redwater River A-66
(Location shown on Plate 13, Lost and Buffalo Springs Creeks)
31. Transect N-N' Redwater River A-67
(Location shown on Plate 10, Timber and Dry Ash Creeks)
32. Transect 0-0' Redwater River A-68
(Location shown on Plate 10, Timber and Dry Ash Creeks)
33. Transect P-P1 Horse Creek A-69
(Location shown on Plate 13, Lost and Buffalo Springs Creeks)
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LIST OF PLATES
Plate
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
Page
Location of Alluvial Valley Floors and Related Features - A-43
Timber Creek Aerial Photograph, MT A-43
Location of Alluvial Valley Floors and Related Features -
Skull and Timber Creeks Aerial Photograph, MT A-44
Location of Alluvial Valley Floors and Related Features -
Nelson Creek (West) Aerial Photograph, MT A-45
Location of Alluvial Valley Floors and Related Features -
Skull Creek Aerial Photograph, MT A-46
Location of Alluvial Valley Floors and Related Features -
McGuire Creek Aerial Photograph, MT A-47
Location of Alluvial Valley Floors and Related Features -
Nelson Creek (East) Aerial Photograph, MT A-48
Location of Alluvial Valley Floors and Related Features -
Dirty Creek Aerial Photograph, MT A-49
Location of Alluvial Valley Floors and Related Features -
Horse and Prairie Elk Creeks Aerial Photograph, MT A-50
Location of Alluvial Valley Floors and Related Features -
Photograph, MT A-54
Valley Floors and Related Features -
Creeks Aerial Photograph, MT A-55
Valley Floors and Related Features -
Cow Creek (West) Aerial Photograph, MT A-56
Location of Alluvial Valley Floors and Related Features -
Buffalo Creek Aerial Photograph, MT A-57
Location of Alluvial Valley Floors and Related Features -
Lost and Buffalo Springs Creeks Aerial Photograph, MT A-58
Location of Alluvial Valley Floors and Related Features -
McCune Creek Aerial Photograph, MT A-59
Location of Alluvial Valley Floors and Related Features -
Cow Creek (East) Aerial Photograph, MT A-60
Location of Alluvial Valley Floors and Related Features -
Duck and Spring Creeks Aerial Photograph, MT A-61
Location of Alluvial Valley Floors and Related Features -
Cottonwood Creek Aerial Photograph, MT A-62
Location of Alluvial Valley Floors and Related Features -
Photograph, MT A-63
Valley Floors and Related Features -
Photograph, MT A-64
Valley Floors and Related Features -
Horse Creek Aerial
Location of Alluvial
Timber and Dry Ash
Location of Alluvial
Berry Creek Aerial
Location of Alluvial
Bluff Creek Aerial
Location of Alluvial
Clay Butte Orthophoto Quadrangle
Location of Alluvial Valley Floors
Bloomfield Orthophoto Quadrangle
Location of Alluvial Valley Floors
, MT.
and
, MT,
and
Related Features -
Related Features -
.A-16
.A-17
Enid SE Orthophoto Quadrangle, MT • A-18
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Plate
23
24
25
26
27
28
29
30
LIST OF PLATES (Continued)
Location of Alluvial Valley Floors and Related Features -
Red Top Orthophoto Quadrangle, MT A-19
Location of Alluvial Valley Floors and Related Features -
Butler Table Orthophoto Quadrangle, MT A-20
Location of Alluvial Valley Floors and Related Features -
Intake NW Orthophoto Quadrangle, MT A-21
Location of Alluvial Valley Floors and Related Features -
McCone Heights Orthophoto Quadrangle, MT A-22
Location of Alluvial Valley Floors and Related Features -
Allard Ranch Orthophoto Quadrangle, MT A-23
Location of Alluvial Valley Floors and Related Features -
Larson School Orthophoto Quadrangle, MT A-24
Location of Alluvial Valley Floors and Related Features -
Knife River Mine Orthophoto Quadrangle, MT A-25
Location of Alluvial Valley Floors and Related Features -
Crane Orthophoto Quadrangle, MT A-26
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INTRODUCTION
Preservation of the hydrologic and agricultural integrity of valley
floor areas in the semi-arid western United States has been an important
concern to government officials, local ranchers, and the coal mining industry
since the beginning of large scale coal strip mining in the late 1960's.
The United States Congress has debated the merits of excluding mining
activities in "alluvial valley floors" in each of its sessions since 1974,
and the Montana State legislature considered a similar action in 1975.
The Coal Mine Operating Regulations adopted in 1976 by the Department of
the Interior state in part that a mine operator shall utilize the best
practicable commercially available technology to minimize, control, or
prevent disturbances to the hydrologic system by procedures including:
"Protecting the quality, quantity, and flow, including depth of flow,
of both upstream and downstream surface and ground water resources of thos
valley floors which provide water sources that support significant vegetation
or supply significant quantities of water for other purposes, by such measures
as relocating and maintaining the gradients of streams, avoiding mining, in-
stalling, reestablishing, or replacing aquifers or aquicludes, and replacing
soil..."
Title 30 Code of Federal Regulations, Part 211.40(a)(7)(iv)
Although to date (January, 1977) no further action has been taken by
the Federal government or any of the states, concern over this issue has
continued to be expressed (Catterall, 1976). It may be reasonably spe-
culated that national legislation will, quite soon, address the issue of
alluvial valley floors in the western United States.
Two major issues have characterized the "alluvial valley floor" debate.
One issue has centered on the importance, characteristics, and areal extent
of these valley floors. Only recently has there been a public awareness
that subirrigated valleys may provide sufficient forage to carry a ranching
operation through dry periods and winter. The other issue has involved
definition of the relationship of "alluvial valley floors" to the western
coal resource and the impact of restricting mining of alluvial valley floors.
This second issue may consist of two phases of impact. The first and always
present phase of conflict or impact is the removal of agricultural use of
the alluvial valley floor during coal mining. The second phase, and the
phase of greatest concern, is that of permanent change of the geohydrologic
character of the alluvial valley floor after mining when such change results
in long-term (post-mining) loss of the agricultural use of the land, prin-
cipally because of the loss of ability to effectively subirrigate grasses for
hay production.
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This report is the result of reconnaissance field work and air photo
interpretation conducted during late summer and fall, 1976. The chief
purpose of the project was the preliminary assessment of the impact of a
prohibition against mining alluvial valley floors on the coal resources
of portions of Dawson, Garfield, McCone, and Richland Counties, Montana
(See Figure 1). A secondary purpose was the assessment of some of the
physical and land use characteristics of these areas, and their importance
to the local farming and ranching economy. Field work, data compilation,
and report preparation were accomplished in less than five months. Thus,
it must be emphasized that the report is reconnaissance in nature. The
report is no substitute for site specific field work related to a par-
ticular mining proposal, which should document ground water levels, sur-
face and subsurface soil and water salinity, aquifer relationships, the
economic importance of a particular valley floor to individual ranchers
and farmers, and identify specific mining and reclamation problems.
Four parts of the four-county area were studied. These are designated
as Area 1 (Burns Creek-Thirteenmile Creek KCLA), Area 2 ( Weldon-Timber
Creek Deposit), Area 3 (Redwater River Deposit) and Area 4 (Eastern Garfield
County). Sufficient coal resource data exist for the first three areas
to permit the preliminary assessment of the amount of coal underlying the
alluvial valley floors. Area 4 ("Eastern Garfield County", which includes
a small portion of McCone County*) encompasses areas nominated for future
coal leasing as a part of the Department of Interior's ,EMARS (Energy Minerals
Activity Recommendation System) process (Superintendent of Documents, 1976)
and quantitative coal resources data are not available. Figure 1 and Table
1 provide the location and correlation of the areas with counties in Montana
and with the available coal data.
* Alluvial valley floors were not mapped in the McCone County portion of
Area 4.
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PREVIOUS WORK
The House Committee on Interior and Insular Affairs (1976) dis-
cussed the definition of "alluvial valley floors" in relation to the
proposed Strip Mining Control and Reclamation Act of that year:
Alluvial valley floors refers to those unconsolidated
deposits formed by streams (including their meanders)
where the ground water level is so near the surface
that it directly supports extensive vegetation or where
flood stream flows can be diverted for flood irrigation.
H.R. 9725 defines alluvial valley floors as, "the uncon-
solidated stream laid deposits holding streams where
water availability is sufficient for subirrigation or
flood irrigation agricultural activities". (Sec. 701
(27)). In more technical terms, alluvial valley floors
are the upper, near-horizontal surface of the unconsol-
idated stream-laid deposits which border perennial, in-
termittent, or ephemeral streams. The alluvium that makes
up the stream-laid deposits is composed of clay, silt,
sand, gravel, or similar detrital material that has been,
or is being, transported and deposited by streams. Al-
luvial valleys within this definition are traversed by
perennial or intermittent streams or by ephemeral stream
channels; are irrigated in most years by diversion of
natural flow or ephemeral flood flow on the modern flood
plain and adjacent low terraces or by subirrigation of
the flood plain by underflow; and are used for the pro-
duction of hay and other crops that are an integral part
of an agricultural operation. Excluded from the defin-
ition are the colluvial and other surficial deposits
that normally occur along the valley margins, are higher
than the modern flood plain and low terraces, are not
irrigated by diversion of natural flow or by ephemeral
flood flow, and are not subirrigated by underflow. It
should also be noted that alluvial valley floors must be
an integral part of a drainage network that transverses
the area under consideration. These are part of through
flowing stream (hydro!ogic) systems and are not small
areas of isolated internal drainage. (House Committee
on Interior and Insular Affairs, 1976.)
Thus, the important aspects of alluvial valley floors include (1)
the ability of a stream system, or its related ground water system, to
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provide enough water to sustain vegetative growth through the dry peri-
ods of the year, and (2) the ability of low stream terraces to be either
subirrigated by near-surface ground water flow or flood irrigated by
natural stream flood flows (including simple diversion of stream flows).
The specification of definitive characteristics of alluvial valley
floors has been important, since geologic deposits of alluvial origin
overlie much, if not all, of the coal resource areas of the Northern
Great Plains. Unconsolidated alluvial deposits exist on some inter-
stream divides and along the margins of many existing valleys in eastern
Montana. It is clear from the House Committee Report language, however,
that alluvial valley floors are the floodplain and low terrace areas of
certain existing stream valleys and are not necessarily all alluvial de-
posits found in any topographic locality.
Malde and Boyles (1975) published maps of alluvial valley floors
and strippable coal reserves for forty-two quadrangles in the Powder
River Basin, Montana. Mapped as alluvial valley floors were the stream
channel, floodplain, and low alluvial terraces that might be subirri-
gated or irrigated by diversion of flood waters. Generally, these ter-
races were not higher than 1.5 m* above the channel floor of small streams
nor higher than 2.4 m above the channel floor of principal streams. Ter-
race areas narrower than 7.6 m were not mapped. Vegetation of these areas
was identified as being principally grass mixed with silver sagebrush
( Artemesia cana ) along small streams and headwater areas. In a letter
to then Representative John Melcher (Montana), U.S. Geological Survey
Acting Director M.R. Klepper stated, in 1976, that the USGS believed that
Malde and Boyle's mapping criteria were consistent with the 1976 House
Committee Report and that the published maps were indicative of the re-
lationship of alluvial valley floors to strippable coal reserves in other
portions of the Powder River Basin (Klepper, 1976).
Malde and Boyles found that of the 158,637 ha** of surface within
the study area underlain by strippable coal, only 4,247 ha were also
alluvial valley floors. This amounts to 2.67 percent of the land surface
overlying surface-minable coal resources (House Committee on Interior and
Insular Affairs, 1976). Strippable coal data was taken from Matson and
Blumer (1973) and includes deposits under less than 46-76 m of overburden,
depending on the thickness of the underlying coal.
In 1976, the Office of Energy Activities, Environmental Protection
Agency, Denver, reported that 10,878 ha of the 370,370 ha presently leased
for coal mining in eight western states meets the alluvial valley floor
criteria of proposed 1976 Federal legislation. This amounts to 3 percent
of the area of the leased land. EPA utilized air photos for its analysis
and followed Malde's mapping criteria. Generally, EPA excluded valleys
narrower than 15 meters in width (Environmental Protection Agency, 1976).
* 1 meter = 3.28 feet
** 1 hectare = .003861 square miles
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No other published work exists that addresses, specifically, the
relation of coal strip mining to valley floor areas. There are num-
erous ongoing studies related to determining the feasibility of mining
and the associated environmental impacts that encompass alluvial valley
floors in Montana and Wyoming; however, seldom have the investigations
provided sufficient data to describe key characteristics and roles of
alluvial valley floors.
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Table 1
Study Areas and Locations
Area Area
Number Name
1 Burns Creek-Thirteenmile Creek
Known Coal Leasing Area
2 Wei don-Timber Creek Deposit
3 Redwater River Deposit
4 Eastern Garfield County
Counties
Dawson
Richland
McCone
McCone
Dawson
McCone
Garfield
Source of
Coal
Data
Spencer (1976)
Matson (1970)
Matson (1970)
None
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METHOD OF INVESTIGATION
This report includes sets of maps of four areas within Dawson,
Garfield, McCone, and Richland Counties. The maps are contained in the
Appendix of this report (Pg.A-1 et seq.). Figure 2 shows the four-county
area and the four areas of specific study. It provides an index to the
topographic maps, orthophoto quadrangle maps and to aerial photo maps con-
tained in the Appendix. Mapping of alluvial valley floors was also com-
pleted, but not included in this report, for all of Dawson County north-
west of the Yellowstone River, and most of McCone County, outside the
areas of specific study. The four areas of specific study are Area 1,
the Burns Creek-Thirteenmile Creek Known Coal Leasing Area in Dawson and
Richland Counties; Area 2, the Weldon-Timber Creek strippable coal area
in McCone County; Area 3, the Redwater River strippable coal area in
McCone and Dawson Counties; and Area 4. the Eastern Garfield County area
in Garfield and McCone Counties,
Mapping of valley floor areas for this report was accomplished
using available air photographs, supplemented by field reconnaissance
performed within the constraints of time and access. Full stereo photo-
graphic coverage was available only for McCone County. USGS 7% minute topo-
graphic quadrangle maps do not exist for any of the study areas of
McCone County. The scales and sources of aerial photographs used are in-
dicated on Table 2.
Following an initial field review, alluvial valley floors in Dawson
County were mapped on air photos, then checked and revised in the field
in late August. Field work in McCone and Richland Counties was conducted
in September. Field work in Garfield County was conducted in early
November. Air photo interpretations for these last three counties were
made after field work was completed in an area. In early November veg-
etation was specifically evaluated in the Burns Creek-Thirteenmile Creek
Known Coal Leasing Area and the Redwater River area.
Valley floors in Dawson and Richland Counties were investigated in
the field at almost all sites accessible by road or trail. It is es-
timated that over 75 percent of the alluvial valley floor contacts in
the Burns Creek-Thirteenmile Creek KCLA (Area 1) were verified in the
field. Due to time and access constraints, fewer sites were mapped in
the field in McCone and Garfield Counties (Areas 2, 3, and 4). It is
estimated that about 50 percent of the alluvial valley floor contacts
in the Redwater River area (Area 3) were mapped in the field. Alluvial
valley floor mapping in the Weldon-Timber Creek (Area 2), and Eastern
Garfield County (Area 4) areas is based on fewer field confirmations.
Field mapping of alluvial valley floors consisted of mapping low
terrace areas and their height above the channel bottom or water level
observed in standing pools. Vegetative characteristics of terraces were
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Figure 2 - Study Area Showing General Location of Alluvial Valley Floors
and Indicating Location of More Detailed Maps
MIM* CfiEE* fCLj* ^ / «~~ y '„,-„
-"-*--
STUDY AREA SHOWING GENERAL U1CATION OF ALLUVIAL VALLEY FLOORS
mraTiON tiF HORF nnAiira rap
--SPECIFIC STUDY AREA'S AND INDEX TO TOPOGRAPHIC 'UAIRANGLES AND AIR PHOTOS
-ALUJVIAL VALLEY FLOORS (NOT TO SCALE)
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noted. Since field work was done in late summer and fall, water levels
in channels may represent water table levels in the alluvial aquifer,
although perched water tables might exist. All lands flood irrigated
for hay or cut for hay were mapped when observed. Apparent areas of
saline seeps in valley floors and salt crusts along channels were also
mapped based on field observations.
Numerous discussions were held with ranchers concerning their pre-
sent and future use of valley floor areas, known water table levels, and
salinity problems.
Mapping of high terraces, labeled "related alluvial deposits", was
based principally on air photo interpretation. Due to the incomplete
availability of stero air photo coverage, the accuracy of mapped contacts
is only fair, perhaps 1 50 meters, with least accuracy occurring in areas
of low relief. The mapping does, however, provide an indication of the
extent of these deposits.
Strippable coal data was obtained from Matson (1970), Spencer (1976),
and the USGS (1976). The assessment of the strippable coal tonnage under-
lying alluvial valley floors and related alluvial deposits was completed
by measuring the area of valley floors overlying coal on maps and air
photos using a polar planimeter. Coal seam thickness was estimated using
published reports. The tonnage of coal was calculated by multiplying
the volume of coal (area thickness of coal) by 12,787 metric tons, the
weight of a hectare-meter* of lignite used by Matson (1970) and Spencer
(1976). The assessment of coal tonnage underlying valley floors in the
Wei don-Timber Creek as well as the Redwater Areas of McCone County is less
accurate than in the Burns Creek-Thirteenmile Creek KCLA in Dawson and
Richland Counties since mapping was done on uncorrected air photos. No
coal resource data were available for the eastern part of Garfield County.
All coal in the specific study areas is of lignite grade.
* the weight of a layer of coal covering one hectare in area and one meter
thick.
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Table 2
Sources of Air Photos Used For Mapping
County
Dawson
Source
Dawson County Land
Office
Scale
1:15840
Date
1958
Richland
SCS
1:27000
1975
McCone
ASCS
USGS
1:40000
1:76000
1970
1974
Garfield
ASCS
1:20000
1968
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MAPPING UNIT DEFINITIONS AND APPLICATION
It is important to note that this effort developed a somewhat more
comprehensive identification of the geologic (and gemorphologic) system
related to alluvial valley floors than had been previously demonstrated.
In addition to the identification of alluvial valley floors, "related
alluvial deposits" were mapped. These related alluvial deposits are a
geologic mapping unit that generally surrounds the alluvial valley floor
(a.v.f.) and is related, hydrologically, to the alluvial valley floor by
virtue of at least its appearance of being in hydrologic continuity with
the alluvial valley floor. Often the related alluvial deposits include
wildlife areas and marsh areas in addition to the agriculturally important
alluvial valley floors. This section describes criteria used to identify
"alluvial valley floors" and "related alluvial deposits." These were used
to designate areas that often were found within alluvial valley floors.
Similarly, "gravel bed areas," "wildlife areas," and "marsh areas" are
described.
Alluvial Valley Floors were mapped as the low terrace, floodplain,
and channel of major drainages and those minor drainages whose low
terraces were either used in part for hay production or which appeared
to have the potential for such use. These areas, where not over-grazed,
support hay production or natural vegetation dependent upon greater
moisture than that supplied by annual precipitation. The source of this
additional moisture is assumed to be either ground water at levels ac-
cessible to vegetation, or seasonal flood flows. Mapped low terraces
vary in height above the present channel, generally in relation to size
of the stream, with higher terraces above larger streams.
The mapped alluvial valley floor of the Yellowstone River is about
three to four meters above the present river and conforms to the "younger
and lower floodplain terrace gravel" mapped in the Girard coal field
(Prichard and Landis, 1975). These Yellowstone River terraces are ex-
tensively farmed for sugar beets and corn, and gravel does not impede
farming. These deposits differ from the gravel deposits of smaller valleys
discussed under the heading "gravel bed areas" in that they are not poorly
sorted and relatively thick deposits of gravel upon which hay does not
grow in great quantity. Mapped terraces along the Redwater River and
Little Dry Creek are within 2.4 to 3 m of the observed water level in
standing pools in the channel (Transects M-M1, N-N1, 0-0'). Mapped ter-
races of smaller streams are within 2.4 m or less of the channel bottom
or observed water level, and are usually within about one to 1.5 m of
the channel bottom in the narrowest mapped valley floors. On several
incised streams, the lowest terraces exhibiting vigorous vegetative growth
are_narrow and sinuous. Correlation with mapped hay lands allows eval-
uation of the present land use of these mapped valley floors. Deeply in-
-12-
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cised valleys, terraces without vigorous vegetative growth and valleys
with extensive surfaces covered by gravel were not mapped as alluvial
valley floors.
The criteria used for mapping alluvial valley floors in this report
are believed to be consistent with previous work and with the intent of
proposed 1976 Federal legislation. A field review with Malde was con-
ducted in July, 1976, to help ensure consistency with similar mapping
in the Powder River Basin. The inclusion of terraces somewhat higher
than in other work is justified both because these terraces exhibit
characteristic valley bottom vegetation and because some local ranchers
raise hay on these terraces. The inclusion may be expected since the
areas herein described are in a different physiographic region than those
of previous studies. In cases where multiple terraces exist, however,
only the lower terraces have been mapped within the alluvial valley floor.
Thus, not all terraces used for hay production are included within the
alluvial valley floor unit; many hayfields are found in areas mapped
in the more extensive "related alluvial deposits."
Related Alluvial Deposits are the high terrace areas of streams
whose lowest terraces are mapped as alluvial valley floors. They have
been mapped in the Burns Creek-Thirteenmile Creek KCLA, along the Red-
water River, and in Garfield County, These deposits also include some
colluvial areas probably underlain by alluvium. Related alluvial deposits
are mappable between discontinuous alluvial valley floors but are iden-
tified on the maps or this report for only short distances upstream from
the alluvial valley floors. These related alluvial deposits could be
mapped to the headwaters of each tributary.
The purpose of mapping related alluvial deposits is to show the
extent of the entire valley fill area. This wider area is often the site
of some type of agricultural activity and a source of recharge for ground
water. In most cases, the alluvial ground water system was estimated to
be integrated throughout the valley fill deposit. Thus, any prohibition
of mining in areas where such activity might detrimentally affect the
alluvial ground water system might likely include prohibition of mining
elsewhere in the valley fill. The mapping of these areas permits an
assessment of the coal tonnage underlying them.
Saline soil and saline outbreaks are either those areas where an in-
dication of saline water or soil was observed on the land surface, such
as a salt crust or saline seep, or areas mapped as saline soil in the
Dawson or McCone soil surveys. Saline land was mapped as a discrete soil
type in the Dawson survey. The Dawson soil description reads:
-13-
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Saline land consists of nearly level areas of poorly
drained, stratified, loamy soil material that contains
such large quantities of soluble salts and alkali that
only the most salt-tolerant native plants can grow.
Most areas have crusts of white salt on the surface
and many seams of salt. Most areas have a water table
at or within a few inches of the surface during most of
the growing season in most years. (Holder and Pescador,
1976).
Available data on saline soils in McCone County were obtained from the
survey in progress (Don Strom, Project Leader, McCone County Soil Sur-
vey, personal communication). The saline soils mapped in this effort
are equivalent either to "typic fluvaquents on 0-2 percent slopes and
saline", or to the Alona series used in the soil survey. Typic fluvaquents
are generally silt loam soils on floodplains of streams of the unglaci-
ated portion of the county. These saline soils tend to have surface
and subsurface gypsum crystals. The Alona soils are well-drained silt
loams formed in calcareous alluvium with a moderately alkaline surface
layer. The subsoil of the Alona soils is moderately to strongly alka-
line, and the underlying material is strongly alkaline (Strom, in
progress). These saline soil areas were mapped to show one of the
potential limitations to agricultural use of valley bottom lands.
Saline channels indicate potentially unacceptable water quality for
irrigation, and saline terraces indicate areas where cropping might
prove unsuccessful.
Inspection of the maps and air photos shows, nonetheless, that
saline bottom lands are cropped for hay in several places. Often al-
falfa is used to control salt or alkali build-up. In other cases,
saline bottom lands produce acceptable crops of natural hay.
Hayed lands include all valley bottom and nearby lands where hay,
either natural or alfalfa, was observed to be harvested, and lands
observed to be irrigated for that purpose. Also included are irrigated
lands observed on air photos and lands mapped as such by the Montana
Water Resources Board in its various Water Resources Surveys. (MWRB,
1970, 1971a, 1971b, 1971c). These surveys represent complete evalua-
tions of irrigated lands up to the publishing date for each survey.
Also included are lands presently taxed as "wild hay lands" in
Dawson and McCone Counties under the Montana Agricultural Land Class-
ification. Irrigated lands in the Yellowstone River valley are not
mapped since hay is not an important crop in that area.
Gravel bed areas represent those valley bottom areas where gravel
is so abundant as to limit any land use except grazing. These areas
occur only in the Burns Creek-Thirteenmile Creek area where streams
-14-
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such as Dunlap and Crane Creeks, cut through the Flaxville and
Cartwright Gravels. Most mapped gravel areas were observed in the
field.
Wildlife areas are those valley bottom lands in headwater areas,
generally wider than 7,0 m bounded by high bluffs and dense tree and
brush growth; areas that were not mapped as alluvial valley floors.
They represent important sources of browse and cover for mammals and
game birds. These areas are generally found in "breaks"* areas and
are usually not used for farming. These areas are also important for
shelter and browse for livestock.
Marsh areas are those areas too wet for any agricultural use or
are local low-lying, subirrigated areas not integrally related to the
drainage system. They often provide excellent waterfowl habitat.
* A relatively abrupt change in topography such as at the edge of terraces
or at the head of a river. The land surface is relatively rough or
broken.
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COAL DATA
Strippable coal data are incomplete for the general study area.
The specific study sites, designated Areas 1, 2, and 3, in McCone and
Dawson Counties represent the only mapped strippable coal data for the
entire study area. The interpretations of High, Moderate, and Low
Potential Coal Development Areas within the Burns Creek-Thirteenmile
Creek KCLA (USGS, 1976) are based on the"work of Spencer (1976). These
categories of potential coal development are based generally on over-
burden thickness modified by the thickness of the underlying coal. The
coal potential development analysis of Spencer has been conducted to
assist the Bureau of Land Management in developing management policies
for mineral development. The Potential Coal Development maps are not
intended as a regular publication of the USGS but are chiefly used as
an internal government planning tool.
The work of Matson (1970) in McCone County provides an evaluation
of coal reserves generally comparable to the USGS analysis in High
Potential Development Areas. Matson's data were used to determine
strippable coal areas in the Wei don-Timber Creek and Redwater River
strippable coal areas. Matson mapped coal deposits under less than
45.8 m of overburden, generally the same criteria as for High Potential
Development. No strippable coal data have been published for Garfield
County and thus the coal resource has not been evaluated in Area 4.
In an attempt to indicate other areas outside of those presently
mapped as strippable, Bureau of Land Management sections nominated by
industry for coal leasing have been mapped in McCone and Garfield Counties
(Bureau of Land Management, 1976). No data are offered as to how much
coal exists or at what depth is occurs in these sections. They are mapped
only to indicate industry interest in localities. Since Bureau of Land
Management control of minerals is geographically limited to certain land
sections, a checkerboard pattern of nominated sections is evident. Inter-
vening private and state sections are likely to have coal deposits of
commercial interest where surrounding Bureau of Land Management sections
have been nominated.
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PHYSIOGRAPHIC DESCRIPTION OF STUDY AREAS
All four study areas are characterized by rolling hills and open
valleys (Figure 2). Most flat and gently sloping lands are dryland
farmed for winter wheat in Dawson, Richland, and McCone Counties. Ex-
tensive ground breaking is currently taking place in Garfield County.
Topographic relief is low in the area; total relief in the Burns Creek-
Thirteenmile Creek KCLA is about 366 m, and in all of McCone County,
maximum relief is only 396 m (Collier and Knechtel, 1939). The only
perennial stream in the four study areas is the Yellowstone River.
The other two principal streams, the Redwater River and Little Dry
Creek, cease flowing in late summer but hold water in large pools ir-
regularly scattered along the channel course. Some smaller streams
also hold water in standing pools after flow ceases; others dry up
completely.
The entire area receives only limited rainfall. Annual precip-
itation averages between 30 and 36 cm* in each study area. For the
period January to November, 1976, Circle, in McCone County, received
3.7 cm of precipitation below its normal of 31.7 cm, and Glendive, in
Dawson County, received 1.1 cm below its normal of 35.1 cm (U.S. Depart-
ment of Commerce, 1976).
All areas are underlain by flat lying or gently dipping beds of
the Tongue River Member of the Fort Union Formation. Gravel deposits
of Pleistocene and pre-Pleistocene erosion surfaces cover much of the
flat table lands of the Burns Creek-Thirteenmile Creek KCLA. The study
areas were moderately affected by Pleistocene glaciations. Ice did
at one time cover the eastern third of the Burns Creek-Thirteenmile
Creek KCLA and the northern fringe of the Redwater River study area.
The Redwater River valley, and its tributaries were inundated by glacial
Lake Circle during this time, as ice blocked the northward flowing
stream. Glacial Lake Jordan covered the southwestern part of the
Wei don-Timber Creek area and much of the eastern Garfield County area
(Colton, et.al., 1961). Glacial Lake Lambert, near the present town of
Lambert, Montana drained down the present North Fork of Burns Creek,
cutting an impressive valley which is wider and flatter than other
streams of comparable size in the area (Howard, 1960). Except for the
North Fork of Burns Creek and small valleys farther east, however,
the situation of underfit streams is non-existent and the terrace
sequence found along the streams of each of the areas has developed
since retreat of the ice (i.e., post-glacial).
* 1 cm = 0.39 inches
-17-
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ESTIMATES OF AREA INVOLVED AND COAL RESOURCE
UNDERLYING ALLUVIAL VALLEY FLOORS
The results of this study are presented in several topographic
maps, photo-maps, tables, and cross sections provided in the Appendix.
Figure 2 shows the four study areas and the mapped alluvial valley
floors of each area. This figure also serves as an index for topo-
graphic quadrangles and aerial photos of a more detailed nature. Topo-
graphic 7%-minute quadrangle maps (Figures 3-13) show alluvial valley
floors, related alluvial deposits, and strippable coal in the Burns
Creek-Thriteenmile Creek KCLA (Area 1). Also included are othophoto
quadrangles (Plates 20-30) of the same area showing characteristics
of the alluvial valley floors. Plates 1-19 are mapped air photos showing
coal resources, alluvial valley floors, and valley floor characteristics
in the Wei don-Timber Creek (Area 2) and Redwater River strippable coal
areas (Area 3). Also included are maps of alluvial valley floors, re-
lated alluvial deposits, and nominated coal lease tracts in eastern
Garfield County (Figures 14-17). Transects showing the topography and
vegetation at selected points across the alluvial valley floors are
provided in the Appendix (Figures 18-33).
The amounts of coal underlying valley floors have been estimated
for the Burns Creek-Thirteenmile Creek KCLA and the Wei don-Timber Creek
and Redwater River strippable coal areas. Since no strippable coal data
or thickness-of-coal data have been published for eastern Garfield County,
no tonnage estimates were made. Maps of this area are included to permit
visual evaluation of the relation of alluvial valley floors to lands of
potentially strippable coal (industry nominated BLM lands) and to permit
evaluation of the characteristics of those alluvial valley floors.
The evaluation of coal tonnage underlying valley floors shows that:
1. A small percentage of the total reserves of the high potential
strippable coal deposits of the Burns Creek-Thirteenmile Creek
KCLA (Area 1) and the Weldon-Timber Creek (Area 2) strippable
coal area underlie alluvial valley floors (1.5 and 2.4%, re-
spectively).
2. A small (2.8%) percentage of the reserves in Area 1 underlie
the entire valley fill (mapped as related alluvial deposits)
of the valleys containing alluvial valley floors.
3. Eight percent of the tonnage of the Redwater River strippable
coal deposit (Area 3) underlies alluvial valley floors and
about sixteen percent underlies the entire valley fill area
of the valleys containing alluvial valley floors.
-18-
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4. Examination of the mapped air photos for the Redwater River
deposit (Area 3) shows that in some areas, the organization of
mining units might be constrained by the prohibition of mining
in the alluvial valley floor and related alluvial deposits. As
such, the affected reserves might be much greater than the
percent of the tonnage if mining were prohibited in the entire
valley fill.
The development of coal strip mines depends on the ability of
a company to economically recover the coal reserves of an area.
It is important for a company to balance areas of thick and thin
overburden so that steady production levels are maintained.
Thus, the prohibition of mining in the valley floor of the Red-
water River, where overburden thickness is least, might limit
the ability of a company to mine other areas of greater overburden,
It appears that despite the potential for alluvial valley
floors to affect the creation of logical mining units in the
Redwater River deposit area, substantial strippable coal re-
serves remain available in the area.
5. A similar situation to that cited in (4) does not appear to be
the case in either the Burns Creek-Thirteenmile Creek KCLA or
the Wei don-Timber Creek strippable coal deposit (Areas 1 and 2).
In other words, in Areas 1 and 2, the constraints on mining
that would be imposed if operations had to avoid alluvial
valley floors would probably not be great.
-19-
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Area 1 Burns Creek - Thirteenmile Creek KCLA
The results of field mapping in Area 1 are contained in a combination
of topographic quadrangle maps (Figures 3 through 13), orthophoto quad-
rangles (Plates 20 through 30) and transects drawn in cross-section (Fig-
ures 18 through 29). All are contained in the Appendix. The topographic
maps provide coal resource data and show the location of alluvial valley
floors and the surrounding related alluvial deposits. The orthophoto
quadrangles show the identical alluvial valley floors, plus upstream wild-
life areas. These wildlife areas are mapped as extending well up into the
headwaters of the major drainages (See Clay Butte Orthophoto: Plate 20).
Hayed lands and saline areas are also mapped in the orthophoto quadrangles
(e.g., Butler Table Orthophoto: Plate 24). Note that in some instances
the hayed lands are completely within the alluvial valley floors (Plate
25 Intake NW) while in other areas the hayed lands extend into highland
areas (Plate 20 Clay Butte).
The locations of transects are shown on the orthophoto quadrangles.
The transects provide more detailed analyses of the topography and vege-
tation found at selected locations in Area 1. Specific vegetative communi-
ties are described and located along with designations of alluvial valley
floors and wildlife areas where encountered.
Of the 2.64 billion metric tons* of coal lying under less than 45.8m
of overburden (High Potential Development Areas) in the Burns Creek-Thir-
teenmile Creek KCLA (Spencer, 1976), 39.18 million metric tons underlie
alluvial valley floors mapped and 72.20 million metric tons underlie the related
alluvial deposits mapped of these same valleys. These constitute 1.5 per-
cent and 2.8 percent, respectively, of the high potential development coal
reserves. Table 3 summarizes the affected reserves in each quadrangle for
these levels of potential development. No alluvial valley floors were
identified in areas investigated north of Clay Butte, Enid SE, and Butler
Valley, (Figures 3, 5, 7), within the KCLA boundary. Coal reserve data
from Spencer (1976) for these quadrangles is included in the data for
total KCLA reserves.
* 1 metric ton = 1.10 short tons
-20-
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Table 3
Tons of Coal Underlying Alluvial Valley Floors (AVF)
And All Related Alluvial Deposits (AD)
Burns Creek-Thirteenmile Creek KCLA
USGS 7.5-minute High Potential Moderate Potential Low Potential Total
Quadrangle Development Area3) Development Area3) Development Area3)
Map (Million Metric Tons)(Million Metric Tons)(Million Metric Tons)
Allard Ranch
(Figure 10)
Bl cornfield
(Figure 4)
Butler Table
(Figure 7)
Clay Butte
(Figure 3)
Crane
(Figure 13)
Enid SE
(Figure 5)
Intake NW
(Figure 8)
Larson School
(Figure 11 )
McCone Heights
(Figure 9)
AVF
4.7
0.5
13.7
1.3
0.4
3.5
12.2
ADC) AVF ADC) AVF
9.1
0.5
30.4 1.8 1.8 9.9
2.4
1.8
5.6 11.8 13.5 8.5
17.1
0.3
0.4
ADC) AVF
4.7
0.5
12.1 25.4
1.3
0.4
8.8 23.9
12.2
ADC)
9.1
0.5
44.3
2.4
1.8
27.9
17.1
0.3
0.4
36.4
67.0 13.6
15.6 18.4
20.9 68.4 103.9
Estimated Total
Reserves in KCLA
(Spencer, 1976)
2400
1600
2400
6400
Percent of Reserves
Under Alluvial Valley
Floors and Alluvial
Deposits 1.5%
2.8% 0.
1.0% 0.8%
0.9% 1.1% 1.6%
a) Potential for mining of coal determined by Spencer (1976). "High Potential" for
extraction exists with shallow overburden and thick coal. Coal data are based on
the Pust Seam.
b) 1 metric ton = 1.10 short tons
c) Related alluvial deposits include alluvial valley floors.
-21-
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Table 4 shows that only 536 ha of alluvial valley floors were mapped
within the KCLA, and that the entire mapped alluvial deposts amounted to
1,168 ha. The total area of alluvial valley floors outside the KCLA was
not determined.
Table 4
Area of Alluvial Valley Floors (AVF) and All Related
Alluvial Deposits (AD) Overlying Coal Reserves
Burns Creek-Thirteenmile Creek KCLA
High Potential
Total
Quadrangle Development Areaa) Development Areaa) Development Area3'
Map (hectares)b) (hectares)1^ (hectares)b)
Allard Ranch
Bloomfield
Butler Table
Clay Butte
Enid SE
Intake NW
Larson School
McCone Heights
AVF
31.08
5.18
98.42
36.26
25.9
90.65
ADC) AVF ADC) AVF
59.57
5.18
391.1 12.95 12.95 69.93
80.29
41.44 88.06 101.01 77.70
132.10
10.36
7.70
ADC) AVF ADC)
31.08 59.57
5.18 5.18
85.47 181.30 489.51
36.26 80.29
98.42 191.66 385.91
93.24 132.09
10.36
7.70
536.13 1168.09
a) Potential for mining of coal determined by Spencer (1976). "High Potential" for
extraction exists with shallow overburden and thick coal. Coal data are based on
the Pust Seam.
b) 1 hectare = .003861 square miles.
c) Related alluvial deposits include alluvial valley floors.
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Area 2 Wei don-Timber Creek Deposit
The results of field mapping in Area 2 are contained on aerial photographs
(Plates 1 through 8) contained in the Appendix. These plates illustrate the
alluvial valley floors. The areas of stn'ppable coal mapped by Matson (1970)
are shown along with legal descriptions of lands nominated for future competi-
tive coal leasing as part of the EMARS process of the Department of Interior's
land planning system. Hayed lands and areas of saline soils were also mapped.
Wildlife areas extending upstream from the alluvial valley floors may be
seen in the Skull Creek (Plate 4) and other areas.
Noteworthy is the fact that saline-tending soils exist along many of the
alluvial valley floors. However, it is not uncommon to have hayed lands on
the saline soils of the alluvial valley floors (e.g., Nelson Creek - West
Aerial Photograph, Plate 3). Plates 6 and 7 show examples of some entrenched
streams that provide refuge for wildlife.
Table 5 shows that 2.4 percent of the tonnage of the Wei don-Timber Creek
deposit underlies alluvial valley floors. Only 17.4 million metric tons of
the 722 million metric tons of the entire deposit are under alluvial valley
floors. The "related" alluvial deposits were not mapped for this area. The
areal extent of the high terraces in the valleys of this study area is not
great. It is not felt that substantially greater reserves underlie the related
alluvial deposits than lie adjacent to the alluvial valley floors.
-23-
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Table 5
Area of Deposits and Coal Tonnage Underlying Alluvial Valley Floors
Wei don-Timber Creek Deposit3)
Mapped Air Photo
14
16
17
19
Area (hectares)
AVF
25.90
126.91
88.88
95.83
Tons
(million metric) AVF
1.8
8.3
2.6
3.1
331.52
15.9
Estimated Reserves
in KCLA (Matson, 1970)
657 million metric tons
Percent of Coal Reserves (Tonnage)
Under Alluvial Valley Floors
a) Coal Data for "s" Bed (Matson, 1970)
2.4 percent
-24-
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Area 3 - Redwater River Deposit
In the Redwater River deposit, 8 percent of the coal reserve tonnage
underlies alluvial valley floors, and 15.6 percent underlies alluvial
valley floors and the related alluvial deposits (Table 6). If alluvial
valley floors and related deposits were excluded from mining, other areas
bordering the valley fill of the deposit might become uneconomical to mine
because of problems in developing a logical mining unit. As such, the
estimate of affected reserves might be substantially increased. There are
about 532.40 ha of alluvial valley floors overlying the deposit and about
1,787 ha including related alluvial deposits. Although much of the coal
resource underlies the Redwater River and Horse Creek in the vicinity
of Circle and lies under or near alluvial valley floors, other reserves
are found away from the river valley, expecially in the area between
Buffalo Creek and Duck Creek (see Plate 16). This "upper" coal reserve
is almost totally unaffected by alluvial valley floors. The strippable
reserves are known to extend into Dawson County (Matson, 1970), and these
reserves would be overlain by the alluvial valley floors of Sullivan and
Pasture Creeks (unpublished mapping by author).
The results of field mapping conducted in Area 3 are represented on
aerial photographs (Plates 9 through 19) and transects (Figures 30 through
33). The aerial photographs show alluvial valley floors and the location
of strippable coal deposits as mapped by Matson (1970). Hayed lands, lands
nominated for future coal leasing, and areas of saline soils are shown on
Area 3 photographs as they were for Area 2 (Plates 1 through 8). Wildlife
areas are not mapped, but would be expected to extend upstream from such
tributaries as the North and South Forks of Buffalo Creek (Plate 12), McCone
Creek and Hell Creek (Plate 14). It would appear that much of the hayed
lands are located in areas resembling the related alluvial deposits al-
though they were not mapped. (See, for example, Plate 13.)
Transect locations for Area 3 are shown on the aerial photographs. A
characteristic transition from a blue gramma to a reedgrass-dominated assoc-
iation as one progresses toward the alluvial valley floor is evident in
Figures 30 and 31. In Figures 32 and 33, the reedgrass is replaced by a
saltgrass-dominated association in much of the alluvial valley floor.
-25-
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Table 6
Area of Deoosits and Coal Tonnaae Underlying Alluvial Valley Floors
(AVF) and All Related Alluvial Deposits
Redwater River Deposit
Mapped Air
Photo
Number
1
3
4
8
10
Area (hectares)'3^
AVF ADd)
98.42
170.49
230.51
414.40
15.54
98.42
310.80
603.47
753.69
15.54
Tons (mill
AVF
0.4
6.3
9.0
29.6
1.2
ion metric )c)
ADd)
0.4
11.3
23.6
59.1
1.2
929.81 1,781.92
Estimated Reserves in Redwater
River Deposit (Matson, 1970)
Percent of Coal Reserves (Tonnage)
Under Alluvial Valley Floors
And Alluvial Deposits
46.4
90.6
582 million metric tons
8.0 percent
15.6 percent
a) Coal Data for "s" Bed (Matson, 1970)
b) 1 hectare = .003861 square miles
c) 1 metric ton = 1.10 short tons
d) Related alluvial deposits include alluvial valley floors
-26-
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Area 4 - Eastern Garfield County
Area 4 was examined in a somewhat limited fashion due to the absence of
published coal resource data. As noted earlier, the area was investigated
because of the high degree of interest indicated by nominators of potential
coal lease tracts during the recent call for nominations issued by the Depart-
ment of the Interior under the EMARS.
The results of field investigations of the location of alluvial valley
floors are presented in topographic quadrangle maps (Figures 14 through 17)
in the Appendix. Shown on these maps are the alluvial valley floors, related
alluvial deposits, the sections of land nominated for leasing, and lands that
were in hay production during the field season of 1976. Also shown are
those areas of saline crusts and/or apparent saline seeps where such were
found along the drainage channels.
There appears a moderate degree of positive correlation between the
areas mapped as related alluvial deposits, which include alluvial valley
floors, and the hayed lands. Potential overlap of alluvial valley floors
and surface mineable coal reserves appear to be located principally along
Timber Creek (Figures 14 and 15).
-27-
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VALLEY FLOOR CHARACTERISTICS
Several characteristics of valley floor areas were identified and
mapped. These included vegetation, salinity, gravel areas, hayed lands,
and property value assessment (See plates and figures in Appendix).
The evaluation of valley floor characteristics shows that:
(1) Valley floor areas have different vegetative communities
than upland areas, and that these valley floor areas are more productive
for forage use.
(2) Valley floor productivity in Dawson County is reflected in
higher land value assessments for these areas, however, this is not the
case in McCone County.
(3) The poor condition of most valley floor areas of western
McCone and eastern Garfield County may be a function of grazing pressure,
based on discussions with the SCS. Thus, the potential forage productivity
of these areas is probably much greater than is found today.
(4) Soil salinity is a significant characteristic of many valley
floors of McCone and Garfield County. It is generally considered a
limitation to agricultural use in SCS soil surveys and irrigation
capability surveys by the Montana Water Resources Board. However,
local farms and ranchers have developed many saline areas for hay production.
(5) Although exact percentage figures were not determined, hayed
and irrigated lands in each study area probably comprise no more than twenty-
five percent of the mapped valley floors.
(6) The relationship of silver sagebrush to low terrace areas
observed in the Powder River Basin (Malde and Boyles, 1976) is not clear
within the study area. Dense stands of silver sagebrush were observed on
terraces four meters above the bottom of the dry channel of Prairie Elk Creek
in McCone County; three meters above the channel of the Redwater River; in many
flat-floored valleys in "breaks" country where no channel is observed to
cut the valley floor, and on many alluvial fans in Dawson County. Although
silver sagebrush is often found in valley floor areas, it is not identified
as part of the climax vegetation community of either the overflow or saline
lowland rangesites. Its abundance on valley floor terraces in the study
area may be a function of past grazing pressure.
(7) Important areas of wildlife habitat and livestock shelter
(mapped as Wildlife Habitat) exist in the headwaters of many streams, up-
stream of the agriculturally-important alluvial valley floors. These areas
provide an important contrast in habitat to the general flat-lying and
open character of most of the area. Although the agricultural potential
of these areas is low, they are an important aspect of the wildlife habit.
The main finding is that valley floors in these study areas are most
important as forage producers and secondarily as sites of hay production.
-28-
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Vegetation
Valley floor vegetation is illustrated in the series of transects
prepared for the Burns Creek-Thirteenmile Creek KCLA and for the Redwater
River area, and the preliminary plant coverage summary data for saline
lowland sites in the Weldon-Timber Creek area. Richard Pokorny* ident-
ified species composition for the transects and Richard Prodgers (unpub-
lished) compiled the results of his first field season's work at the
proposed Burlington Northern mine site (within the Weldon-Timber Creek
area) for the saline lowland sites. Comparisons with productivity of low-
land and upland range sites were made using general data available from
the Soil Conservation Service and discussions with Gene Handle, Range
Conservationist, SCS, Miles City.
Typically, species diversity and productivity on lower terraces
increases as available moisture increases. Species such as blue grama
(Bouteloua gracilis) and western wheatgrass (Agropyron smithii) which
are common on upland range sites decrease as a percentage of the total
plant cover with increasing moisture, and there is an increase in species
such as switch panicgrass (Panicum virgatum), kentucky bluegrass
(Poa pretensis), Canada wildrye (Elymus canadensis). prairie sand
reecTgrass (Calamovilfa longfolia), dropseed (Sporobolus spp.) and slender
wheatgrass (Agropyron trachycaulum). Shrubs and trees correlated with
moister conditions include woods rose (Rose woodsii), common snowberry
(Symphoricarpos albus), Canadian buffaloberry (Shepherdia canadensis),
and plains cottonwoods, (Pppulus deltoides). Horsetail (Equisetum spp.)
is also found in some of these areas.
Detailed field investigations were made across drainage channels at
selected locations. The results of these investigations are shown on
transects contained in the Appendix (Figures 18-33). Characteristically,
the larger valley floors of the Burns Creek-Thirteenmile Creek KCLA are
predominantly grass covered with isolated cottonwood and shrub growth
on lower terraces (Figures 18,20,21). Some stream transects have thick
stands of cottonwoods (Figure 19). Upstream transects in wheat fanning
areas show narrower valley floors that are sometimes incised by channels
two meters deep. Alluvial valley floor vegetation usually reflects moist
conditions (Figures 23-26). In "breaks" country, or simply where the
upstream valley has cut a deep flat-floored trench, trees and brush are
common (Figures 22,24). These valleys in "breaks" country have been
mapped as wildlife habitat. The smaller streams of the KCLA, east of
Burns Creek, have vegetation similar to the transects described (Figures
27, 29), or they are gravel bed, braided streams with little surface
vegetation (Figure 28).
*Range Specialist, Montana Reclamation Division
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In many of the headwater areas of streams draining lands where
wheat farming is common, vigorous vegetative growth and subirrigation
is common. Often these stream channels are marshy, and they may, or may
not, be connected with the integrated drainage system. The source of the
waters in these channels is believed to be surface and ground water flow
from nearby wheatfields.
Transects M-M1, N-N1, 0-0' in the Redwater River valley indicate that
vegetation on the widest and most continuous high terraces is more character-
istic of upland areas (Figures 30, 31, and 32). These areas are predominantly
covered by blue grama and western wheatgrass. Only the lower terraces
have vegetation similar to vegetation in the valleys of the KCLA. The
vegetation of Horse Creek (Transect P-P1 in Figure 33) is typical of saline
areas throughout McCone County. Percent coverage of inland saltgrass
(Distich!is stricta) is very high, and trees and shrubs are very rare.
If observed water level in the stream channel reflects water level
in the nearby alluvium, then low terrace vegetation herein described
can be used in future field work in identifying subirrigated areas.
These grass species would identify areas where ground water would be
available for subirrigation of alfalfa or natural hay crops. Only
observation wells can document alluvial ground water table levels.
Table 7 is a summary of plant coverage data for partially to very
saline alluvial terraces near Nelson Creek in the Wei don-Timber Creek
coal deposit area (Prodgers, 1976). These data confirm the signifi-
cance of inland saltgrass on McCone County terraces. Other important
species are blue grama, American bullrush (Scirpus americanus), western
wheatgrass, needle-and-thread (Stipa comata), crested wheatgrass
(Agropyron cristatum), and bluegrass (Poa spp).
The importance of alluvial valley floors for forage production
can be seen in Table 8, which shows production data for the various
range sites of Dawson County. Range sites are groupings of soil types
whose climax vegetative cover is similar. Each range site listed
in Table 8 is thus a soil association that covers a percentage of
the total area of the county. The overflow range site consists only of
channel and terrace soils and the saline lowland range site consists
only of saline channel and terrace soils. It can be seen that forage
production in overflow and saline lowland range sites, which charac-
terize almost all the mapped alluvial valley floors, is higher than for
any other range sites and that production from these range sites in less
favorable years is greater than favorable year production for many of
the county's other range sites.
-30-
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Growing conditions for vegetation of overflow range sites (one of
the kinds of areas characteristic of alluvial valley floors) vary de-
pending on management, but the potential climax community of these
areas is estimated by the SCS to be:
% composition by weight
western wheatgrass 30%
other tall grasses 20%
green needlegrass 15%
woody plants 10%
needle-and-thread 5%
big bluestem 5%
little bluestem 5%
slender wheatgrass 5%
perennial forbs 5%
(Holder and Pescador, 1976)
The SCS makes the following observations regarding the overflow
range site:
This site is mostly in fair and good condition. In
some areas good management has allowed the better grasses
to maintain themselves, and the site is in excellent con-
dition. Most of this site has been overgrazed in the past
by sheep and cattle. In some small areas silver sagebrush,
rosebush, and snowberry have increased and are a dominant
part of the plant cover. This site generally recovers
rapidly if proper grazing use and a planned grazing system
are employed. Response is slow where the plant cover is
dominated by Kentucky bluegrass or smooth brome. Brush
control is feasible in small local areas where silver sage-
brush, rosebush, or snowberry are dominant in the plant
cover. Most of this site is not suited to mechanical im-
provement because of the erosion hazard if the plant cover
is destroyed.
An even balance of grazing between this site and adjacent
sites is difficult to obtain because of the shade, shelter,
longer green grass period, and available water on this site.
Consequently, where tracts of this site are sufficiently
large, grazed areas should be separated by fences to fac-
ilitate good grazing management.
(Holder and Pescador, 1976)
-31-
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Table 7
Summary of plant coverage data for partially to quite saline alluvial
terraces, near Nelson Creek, McCone County. Visual estimates of cov-
erage, modified from Daubenmire (1959), were made for four by eight meter
plots. Data are compiled from twenty plots.
Inland saltgrass
Blue grama
American bull rush
Needle-and thread
Crested wheatgrass
Bluegrass
Triglochin maritima
Alkaligrass
Nuttall saltbush
Fringed sagewort
Alkali cordgrass
Tumblegrass
Treadleaf sedge
Kochia
Plantago patagonica
Rough false pennyroyal
Common dandelion
White milkwort
Foxtail barley
Cheatgrass brome
Plains pricklypear
Broom snakeweed
Common salsify
Blue flax
Yarrow
Small-leaf pussytoes
Common milkweed
American vetch
Silver sagebrush
Scarlet globemallow
Conyza canadenis
Stiff stem flax
Coryphantha vivipara
Indian ricegrass
Constancy!
35%
15%
30%
10%
40%
10%
15%
10%
15%
10%
10%
10%
25%
25%
15%
15%
10%
10%
10%
10%
5%
5%
5%
5%
5%
5%
5%
5%
5%
5%
5%
Average Coverage2
TOTAL
I Constancy = number of plots species found
total number of plots (20)
2 Average coverage
Cover class estimates used in field evaluation were:
Summation of "midpoint." coverage nf species from all plots
total number of plots where species found
T =
1 =
2 =
3 =
4 =
5
6
1%
1-5%
5-25%
25-50%
50-75%
75-95%
95-100%
"Mid point"
1.0
3.0
15.0
37.5
62.5
85.0
97.5
Methodology: designations T through 6
were made in field. Utilizing the con-
versions for these cover classes (e.g.,
2 = 5-25%) the midpoint of each class
was substituted in the equation for
average coverage.
(Prodgers, unpublished)
-32-
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Table 8
Generalized Range Site Productivity Data: Dawson County
(Holder and Pescador, 1976)
range site
alluvial valley floor
overflow
saline lowland
non alluvial valley floor
sands
sandy
silty
clayey
thin hilly
shallow clay
gravel
shallow to gravel
dense clay
panspots
very shallow
saline upland
estimated annual yield
(Kgl of air-dry herbage)
favorable yr.^less favorable yr.
1134
998
916
726
680
590
544
408
363
363
363
363
181
272
680
544
454
408
363
363
45
181
181
181
181
181
91
136
percent of annual yield
available as forage
95%
90%
90%
95%
95%
95%
85%
95%
95%
90%
10%
estimated annual yield of forage
(Kgl of air-dry herbage)
favorable yr^ less favorable yr.
964
948
735
653
646
561
517
347
345
345
327
290
163
27
578
517
408
367
348
348
43
154
172
172
163
145
82
14
1 One Kilogram = 2.2 pounds
2 This is-SCS term; no definition available
-------
Productivity of the saline lowland range site is also high. In
Dawson County, the climax plant community of these areas is estimated to
be:
alkali sacaton 45%
western wheatgrass 15%
saltgrass 10%
alkali cordgrass 10%
alkali grass 5%
slender wheatgrass 5%
bearded wheatgrass 5% (Total exceeds 100% since
sedge 5% certain species occur as
squirrel tail 3% overstory or understory.)
The SCS makes these comments on the saline lowland range site:
Under continued heavy grazing, alkali sacaton and western
wheatgrass decrease and are replaced by saltgrass, mat muhly,
foxtail barley, curlycup gumweed, tumblegrass, rushes, and
annual plants.
The site ranges from fair to excellent in condition, depending
on how severe the use of the area by livestock has been in the
past. In some areas good management has allowed the better
plants to maintain themselves, and the site is in excellent
condition. In some areas saltgrass has increased and is the
dominant plant. This site recovers rapidly when proper grazing
use and a grazing system are employed if enough of the better
grasses are present. These saline-alkali soils are not suited
to mechanical improvement practices.
(Holder and Pescador, 1976)
Range site descriptions for the other study areas are generally
comparable with those of Dawson County (Gene Handle, pers. comm.).
The abundance of inland saltgrass in McCone County and Garfield County is
believed to be a function of sustained high grazing pressure. Rehabili-
tative programs could decrease the coverage of inland saltgrass (Handle,
pers. comm.) in these areas.
These data for overflow and saline lowland sites (Table 8) indi-
cate that the vegetative characteristics of valley floor areas include
differences in species composition and higher forage productivity in
terms of hay production than upland range areas.
-34-
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Saline Areas
The extent of saline lands can be seen on the maps and air photos
of the study areas. Saline soils are most significant in Garfield
County, the Wei don-Timber Creek area, tributaries of the Redwater River
flowing from the west, and much of the North Fork of Thirteenmile Creek.
Salt-lined channels are common in McCone and Garfield County, as are
saline seeps in valley floors. No studies were made of the sources of
this salinity, but it is likely to be a combination of naturally occurring
salts leached from bedrock, aggravated by increased ground water flow in wheat
farming areas. Because wheat fanning is not extensive in the Weldon-Timber
Creek of Garfield areas, salinity is apparently related to natural conditions
in these areas.
Although saline areas are not recommended by the SCS for irrigation
or ground breaking (Holder and Pescador, 1976), many areas are presently
under such use. A portion of the North Fork Thirteenmile Creek, several
eastward flowing tributaries to the Redwater River, and portions of
Timber and Nelson Creeks are under such use. Recent irrigation of
terraces has led to saline problems along Little Dry Creek (T17N, R43E,
Sec.33) in eastern Garfield County. It is difficult to assess the
limitations of salinity on hay production in the saline areas, since
several ranchers raise hay where salinity has been mapped. Over long
periods of time, production is likely to decrease in these areas and
their best use will probably be as rangeland. ~~
Gravel Areas
Gravel bed areas in the Burns Creek-Thriteenmile Creek KCLA are
locally significant where streams drain deposits of the Flaxville and
Cartwright Gravels. The characteristics of such streams have been
illustrated (Transect L-L1). Some gravel areas were found upstream of
the alluvial valley floors mapped (see Figure 11). However, these
areas are probably hydrologically related to the alluvial valley
floors located downstream. The presence of scattered cottonwoods within
the gravel areas indicates the availability of ground water. It is likely
that the gravel areas located upstream of alluvial valley floors, and
upstream of wildlife areas, serve as recharge zones for the alluvial
aquifers. Thus, disruption of these areas would affect the subirrigation
of downstream alluvial valley floors to some, as yet undetermined, degree.
Hayed Lands
Hayed lands include undeveloped lands cropped for hay, flood irrigated
lands, and ditch irrigated lands in all valleys other than the Yellowstone.
Some areas mapped in the Water Resources Surveys as hayed lands may not
be cropped for hay. It is estimated that over seventy five percent of
mapped alluvial valley floors are not currently in hay production.
-35-
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This is probably due to several factors. Some lands are cut only
once every several years for hay and might not have been observed in
1976 or recorded under the land classification. Only systematic con-
tact with all ranchers and farmers could produce data on all lands
ever cut for hay. Also, many of the alluvial valley floors are sinuous
and difficult to crop.
Although data are lacking, conversations with ranchers indicate that
new lands are now being brought into production as the cost of hay in-
creases. This has been observed on Middle Fork Burns Creek and Bluff
Creek in Dawson County.
In the Burns Creek-Thirteenmile Creek KCLA scattered blocks of land
are hayed along North Fork Burns Creek (Plates 24, 26). Most hay is raised
on the high terraces where about one cutting is obtained per year. On lower
Middle and South Forks of Burns Creek (Plates 25, 27), much of the alluvial
valley floors are in hay production or are being brought into production.
Conversations with ranchers indicate that these lands are crucial to success
of the ranchers of this area. Scattered valley floor areas in the upper
portions of the Middle and South Forks of Burns Creek are cropped. This
is an area of extensive wheat farming and interest in hay cropping may
be less than in ranching areas. Little hay cropping is done in the
Thirteenmile Creek drainage (Plates 21, 23). Some portions of the South
Fork of Fox Creek (Plate 28) are used to produce alfalfa. Irrigation in
the Yellowstone River Valley is extensive but is not for hay production.
No flood irrigation from Redwater River onto its terraces has been
observed anywhere in the study area. Lower terraces which might well be
suited for flood irrigation have been mapped as the alluvial valley
floor. Floodflows from tributaries to the Redwater, however, are ex-
tensively diverted onto Redwater terraces at Duck Creek, Buffalo Springs
Creek, and Dry Ash Creek. Haying also takes place on several southeast-
ward flowing tributaries and along Cow, Duck, and Horse Creeks (Plates 15,
19, 9). Ditch irrigation onto high terraces and nearby upland plains also
occurs.
On Timber Creek in the western McCone study area little hay is raised
(Plate 1). On Nelson Creek, however, significant acreage of alluvial valley
floor is used for hay even where soil salinity is high (Plate 6). Also,
parts of Dirty Creek are used for haying (Plate 7). In this study area,
valley floors were the only sites where hay production was found to take place.
Irrigation is extensive along Little Dry Creek in Garfield County (Plate
14). This land is used for hay and wheat production. Lands along the
mainstem of Timber Creek, and in the headwaters of Uall and Crow Rock Creeks
are flood irrigated for hay. No hay production occurs on the mainstems of
Uall or Crow Rock Creeks (Plate 16). Salinity is high in the channels and
the upper terraces are cropped for wheat.
-36-
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Property Value
The Montana Department of Revenue, Property Valuation Division, has
assessed the value of all lands with the state. This assessment serves
as the basis for taxation. Grazing lands are assessed relative to their
productivity. Grades of grazing lands found within the study area are:
Hectares needed for 10-month
grazing season per 454 kg steer
Grade or equivalent
G2B 9-11 ha
G3 ll-15ha
G4 15-22ha
G5 23-40ha
Wild hay land is also classed on productivity. Grades of wild hay lands
found within the study area are:
Grade Metric tons of hay/hectare
W5 2.24-3.14
W6 1.12-2.01
W7 less than 1.12
Assessments were completed in 1962 and reflect land conditions at that
time.
The assessment records for Dawson County were compared with the in-
dicated alluvial valleys using 1:24,000 scale base air photos. Thus, an
overall evaluation of land values in the Burns Creek-Thirteenmile Creek
KCLA could be made. Over ninety-five percent of the mapped alluvial val-
ley floors in the KCLA are classed as G2B lands. Upland areas range in
classification from G2B to G5 with most lands being G3 and G4. In most
areas where wheat farming is the predominanat land use, G2B lands exist
in wide bands along streams, beyond the limits of the alluvial valley
floors. Wild hay lands are sporadically located along streams and range
in classification from W5 through W7.
In contrast, little land in the Weldon-Timber Creek or Redwater River
strippable coal areas is classed G2B. Most of the terrace lands are classed
G3 or G4. Time did not permit mapping to compare lowland and upland areas.
Hay lands are classed W5 or W6.
Thus, it can be seen, that for purposes of land taxation, Dawson County
alluvial valley floors are classified as the most productive rangeland in
the county, and that their productivity is rated higher than valley bottom
lands of McCone County. Productivity of wild hay lands is about the same
in both counties.
-37-
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CONCLUSIONS
This report has indicated the importance of valley floor areas for
the production of forage and in some localities, for the production of
hay. (See page 35.) This report has also shown that substantial coal
reserves with high potential for development exist in areas not over-
lain by alluvial valley floors or their related alluvial deposits. (See
page 18.) Thus, if alluvial valley floors, and their related alluvial
deposits, were protected from surface coal mining, extensive reserves of
coal could still be extracted.
Reconnaissance identification of alluvial valley floors is not a
substitute for detailed ground water studies to actually identify the
nature of the alluvial ground water system of concern to a particular
mining operation. Drilling of observation wells could document not only
the level (elevation) of the alluvial ground water table, but also the
quantity of water flowing in the alluvium and its quality.
This reconnaissance study is also no substitute for a detailed
economic assessment of these valley floor areas. Some mapped alluvial
valley floors in these study areas provide the critical supply of water,
forage, and/or winter feed to the ranching operation using the valley
lands. Other valley floors are viewed by ranchers as a future source of
hay production. Some valley floor areas are little used by livestock but
supply important wildlife habitat. No assessment has been made to date
of the economic importance of these areas; no studies have been made of
how selected ranchers would be affected if the valley floors they uti-
lize were to be lost from production due to failure of revegetation ef-
forts or detrimental off-site impacts. No assessments have been made
of the importance of valley floor habitat to the maintenance of certain
wildlife populations.
The results of this report show that further reconnaissance mapping
of alluvial valley floors might better use characteristic valley bottom
grass species, and observed use of lands for haying, as indicators of
the existence of alluvial valley floors. Indicator grass species, when
identified by a competent field botanist in late spring and early sum-
mer, are believed to provide an excellent characteristic to establish
that certain valleys receive greater than average moisture. Existence
of similiar communities on higher terraces would justify inclusion of
these areas within the alluvial valley floor.
If time does not permit extensive field work, it seems that iden-
tification of hayed lands on air photos provides an excellent indicator
of which valleys have the potential for development of that land use.
Most alluvial valley floors mapped in this study area already are hayed
in part.
-38-
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This report has identified extensive parts of valley floors where
saline soils are predominant. These valley floors serve as important
sources of forage production, where overgrazing has not reduced the
range quality to inland saltgrass dominance. Some of these saline soil
areas are also used to produce hay. Even so, the SCS does not recommend
tillage of these saline soils.
Proposed mining activities in these areas will have to address
these saline conditions. Special handling of saline materials might
permit its burial and improve the quality of ground waters in the alluvial
system. It is also possible that mining activity might detrimentally
affect these saline valley floors if even greater saline concentrations
were the result of mining disturbance. In this latter case, downstream
landowners who might be using valley floors for haying might suffer
productivity losses from an increasingly saline water supply.
Future research concerning alluvial valley floors in the semi-arid west
and the impacts of surface mining should focus on identifying the critical
geologic, hydrologic, biologic factors supporting the agricultural uses of
these lowland and terrace areas. Identification of the factors will assist
in protection of alluvial valley floors by describing the conditions that
must be recreated after mining. The resulting information can be used to
establish mining and reclamation guidelines which enable policy makers to
determine suitability of alluvial valley floors for future mining.
-39-
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ACKNOWLEDGEMENTS
This report was funded by a grant from the Office of Energy Activities,
Environmental Protection Agency, (EPA). The Montana Energy Advisory
Council (MEAC) provided most of the administrative support for the project.
The Montana Environmental Sciences Division donated accounting services
necessary for proper administration of the grant. Without the efforts of
Sharon Solomon, MEAC, and John Hardaway, EPA, this project would not have
taken place. They deserve special thanks.
Budget limitations necessitated the cooperation of several individuals
for the execution of this project. Dr. Harold E. Malde, USGS-Denver,
donated a week's field time at the beginning of the project and assisted
in establishing criteria for alluvial valley floor mapping in the general
study area. Air photos were loaned to the project by Mike Graves, Appraiser,
Dawson County; Allan Barnes, Garfield County Executive Director of the
Agricultural Stabilization and Conservation Service (ASCS); and Gerhard
Knudsen, Circle West program manager, Montana Energy Planning Division
(MEPD). Thomas Osberg, EPA-Warrenton, Virginia, prepared air photos of
Richland County. Max Botz, Montana Water Quality Bureau, provided advice
and aerial reconnaissance flights of the area. Richard Prodgers, plant
ecologist, MEPD, and Richard Pokorny, range specialist, Montana Reclamation
Division, donated field and office time assisting in plant identification
and vegetation data analysis. Shirley Lindsay of EPA carried out all of
the final editing effort.
Two people were especially important to the project. John Herrin
served as field assistant in August and September, 1976, completed the
initial interpretation of valley floors in the Burns Creek drainage, and
assisted in the McCone County work. Barbara Rusmore advised on report
preparation and editing, completed all drafting work, and provided beneficial
support during the project period.
-40-
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U.S. Department of Commerce. 1976. Montana climatological data: monthly
reports. National Weather Service. Asheville, North Carolina.
U.S. Geological Survey. 1976. Coal development potential map: Burns Creek-
Thirteenmile Creek Known Coal Leasing Area, Dawson and Richland Counties,
Montana. Unpublished.
-42-
-------
APPENDIX I
Area 1. Burns Creek - Thirteenmile Creek KCLA
A-l
-------
LEGEND
1:24,000 Topographic Maps
(Figures 3 - 13)
Burns Creek - Thirteenmile Creek KCLA
Alluvial Valley Floors. These are mapped as the low terrace, floodplain, and
channel of major drainages and those minor drainages whose low terraces are
either used in part for hay production or which have the potential for such
use. These areas may include soils which have potential salinity jDroblems.
Areas less than 7 m in width are excluded.
Related alluvial Deposits. Recent (?) alluvial deposits of streams whose low-
est terraces are mapped as alluvial valley floors. Includes surface colluvium
probably underlain by alluvium.
C0AI-
OUTCROP
Coal Potential Development Areas (USGS. 1976*). High Potential Development
Areas: overburden 0-46 m thick and stripping ratio 10:1 or less. Moderate
Potential Development Areas: overburden 46-61 m and stripping ratio 20:1
or. less. Low Potential Development Areas: overburden greater than 61 m and
stripping ratio greater than 20:1. Note: Where High Development Areas are
bounded by areas not designated (blank), the coal outcrops and is not con-
tained in the undesignated area.
* U.S. Geological Survey. 1976. Coal development potential map: Burns Creek-
Thirteenmile Creek Known Coal Leasing Area, Dawson and Richland Counties,
Montana. Unpublished.
A-2
-------
UNITED STATES
DEPARTMENT Of THE INTERIOR
GEOLOGICAL SUPVEY
FIG, 3 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
CLAY BUTTE QUADRANGLE, PIT
A-3
-------
UNITED STATES
DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
BLOOMFIELD QUADRANGLE
5 MINUTE SERIES (TOPOGRAPHIC]
""tl"°a*'"> -*1 -HIGH'
FIG, 4 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
BLOOMFIELD QUADRANGLE, ^T
A-4
-------
UNITED STATES
DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
ENID SE QUADRANGLE
7.5 MIHUTE SEJUES (TOP«JBAPmr ,
FIG, 5 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
ENID SE QUADRANGLE, MT
A-5
-------
UNITED STATES
DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
FIG, 6 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
RED TOP QUADRANGLE, MT
A-6
-------
FIG, 7 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
M
BUTLER TABLE QUADRANGLE, MT
A-7
-------
UNITED STATES
DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
INTAKE NW QUADRANGLE
MONTANA -DAWSON CO,
.5 MINUTE SERIES fTOPOOR
FIG, 8 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
INTAKE NW QUADRANGLE, MT
A-8
-------
UNITED STATES
.riTMENT OF THE INTERIO
GEOLOGICAL SURVEY
CONE HEIGHTS QUADRANGLE ^ ^'
FIG, 9 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
McCoNE HEIGHTS QUADRANGLE, MT
A-9
-------
UNITED STATES
DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
ALLARD RANCH QUADRANGLE
MONTANA
7 3 MINUTE SERIES (TOPOOHAPHIC)
FIG, 10 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
ALLARD RANCH QUADRANGLE, MT
A-10
-------
UNTOD STATES
DEPARTMENT Of THE INTERIOR
OEOLOOICAL SURVEY
LARSON SCHOOL QUADRANGLE
WOWTIWA-OTCHL^HD CO
IS ir.NUTE SEOIES f
FIG, 11 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
LARSON SCHOOL QUADRANGLE, MT
A-n
-------
UNITED STATES
DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
KNIFE RIVER MINE QUADRANGLE
MONTANA -HIGHLAND CO.
75 MINUTE SERIES (TOPOGRAPHIC)
FIG, 12 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
KNIFE RIVER ^INE QUADRANGLE, MT
A-12
-------
\* uwrrco STATES
\-, DEPARTMENT OF TME IHTERIOR
v QCOUXJICAL SURVEY
FIG, 13 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
CRANE QUADRANGLE, MT
A-13
-------
LEGEND
1:24,000 orthophoto quadrangle
maps (Plates 20-30)
Burns Creek-Thirteenmile Creek KCLA
Alluvial Valley Floors. These are mapped as the low terrace, floodplain, and
channel of major drainages and those minor drainages whose low terraces are
either used in part for hay production or which have the potential for such
use. These areas may include soils which have potential salinity problems.
Areas less than 7 m in width excluded.
Hayed lands. Lands where hay was observed to be harvested, and lands irri-
gated for that purpose; irrigated lands mapped by the Montana Water Resources
Board (1970), 1971a) except irrigated lands in the Yellowstone River valley;
and lands appraised as wild hay lands under the Montana Agricultural Land
Classification.
*
3
Saline Soils. "Nearly level areas of poorly drained...soil material that
contain such large quantities of soluble salts and alkali that only the
most salt-tolerant native plants can grow;..Most areas have a water table
at or within a few inches of the surface during most of the growing season
in most years." (Holder and Pescador, 1976)
A-14
-------
* *
Salt Crusts. Surface salt crusts observed in field or on air photographs,
•o*
*
Gravel Areas. Valley bottom areas with high percentages of surface gravels,
Delieved to limit agricultural use.
Marsh Areas. Wetland areas, usually not integrally related to the drainage
system.
/'/
Wildlife Areas. Valley bottom lands, wider than 7 m, with high bluffs on
their margins and generally covered with dense brush and trees.
Location of Transect. (See Figure 18-29) Fiducial marks indicate terminal
points of measurements.
A-15
-------
PLATE 20 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
CLAY BUTTE ORTHOPHOTO QUADRANGLE, MT
A-16
-------
PLATE 21 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
BLOOMFIELD ORTHOPHOTO OUADRANGLE, MT
A-17
-------
PLATE 22 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
ENID SE ORTHOPHOTO QUADRANGLE, MT
A-18
-------
PLATE 23 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
RED TOP ORTHOPHOTO QUADRANGLE, MT
A-19
-------
PLATE 2L\ LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
BUTLER TABLE ORTHOPHOTO PUADRANRLE, MT
A-20
-------
PLATE 25 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
INTAKE NW ORTHOPHOTO QUADRANGLE, ^T
A-21
-------
PLATE 26 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
HEIGHTS ORTHOPHOTO QUADRANGLE, ^T
A-22
-------
PLATE 27 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
ALLARD RANCH ORTHOPHOTO QUADRANGLE, NIT
A-23
-------
PLATE 28 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
LARSON SCHOOL ORTHOPHOTO QUADRANGLE, MT
A-24
-------
PLATE 29 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
KNIFE RIVER ^INE ORTHOPHOTO QUADRANGLE, MT
A-25
-------
PLATE 30 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
CRANE ORTHOPHOTO QUADRANGLE, MT
A-26
-------
TRANSECTS
Transects A - A' through L - L1 Burns Creek - Thirteenmile Creek KCLA
Legend
.0'
VfRT.
loo1 Moat.
Highest evidence of flood flow (where found)
indicated by fiducary marks on either side
of channel.
Location of vegetation survey. Observations de-
scribed below transect in terms of percent
of total vegetative cover each species com-
prises. Descriptions are for a band fifteen
meters wide along transect
(transects based on pace and compass measurements,
not surveys)
Scale
A-27
-------
A'
Location shown on
Plate 25, Intake NW
4 flowing
vf
1 yellow sweetclover 50%
western wheatgrass 20%
blue grama T
western yarrow T
2 yellow sweetclover 50%
western wheatgrass 20%
blue grama T
western yarrow T
Canada wildrye T
3 yellow sweetclover 30%
big bluestem 20%
buffaloberry]
woods rose j 15%
little bluestem 10%
prairie sand reedgrass 5%
western wheatgrass 5%
fringed sagewort 5%
switch panicgrass 5%
5 yellow sweetclover 40%
fringed sagewort 30%
blue grama 10%
cordgrass 5%
western wheatgrass T
creeping juniper swards
reed canarygrass
Kentucky bluegrass
rushes
willow
50%
10%
40%
FIGURE 18
SOUTH FORK BURNS CREEK
A-28
-------
Location shown on
Plate 27, Allard Ranch
1 Kentucky bluegrass 80%
slender wheatgrass 10%
snowberry 10%
goosefoot swards
western Yarrow T
mustard T
quackgrass T
FIGURE 19
MIDDLE FORK BURNS CREEK
A-29
-------
Location shown on
Plate 26, McCone Heights
C'
wet
avf
1 broom snakeweed
crested wheatgrass
fescue
western wheatgrass
broom snakeweed
blue grama
little bluestem
slender wheatgrass
quackgrass
prairie cordgrass
cultivated
15-20%
15%
10%
5%
5%
4 slender wheatgrass
woods rose }
buffaloberry]
common snowberry
switch panicgrass
cordgrass
squirrel tail
40%
40%
10%
3%
T
T
5 baltic rush
100%
western wheatgrass
Kentucky bluegrass
common snowberry
yellow sweetclover
woods rose ]
buffaloberry]
fririqed sagewort
50%
30%
5%
5%
5%
T
6 slender wheatgrass 60%
Kentucky bluegrass 30%
western wheatgrass T
A-30
FIGURE 20
NORTH FORK BURNS CREEK
-------
Location shown on
Plate 24, Butler Table
-avf-
1 common sixweeksgrass 80%
needle-and-thread 5%
junegrass T
blue grama T
horsetai 1 15-20%
fringed sagewort 15%
little bluestern 10%
prairie sand reedgrass 10%
junegrass 7-10%
yellow sweetclover 5%
blue grama T
Kentucky bluegrass T
western wheatgrass T
slender wheatgrass T
baltic rush
switch panicgrass
woods rose J
buffaloberryj
common snowberry
slender wheatgrass
reed canarygrass
4 no vegetation
80%
5%
5%
T
T
T
Kentucky bluegrass 60%
slender wheatgrass 30%
common snowberry 10%
woods rose T
buffaloberry T
Kentucky bluegrass 60%
blue grama 10%
western wheatgrass)
needle-and-thread V 30%
fringed sagewort j
FIGURE 21
NORTH FORK BURNS CREEK
A-31
-------
E'
Location shown on
Plate Z4, Butler Table
wildlife
habitat
Kentucky bluegrass 80%
common snowberry 15%
silver sagebrush
buffaloberry]
woods rose j
5%
5%
2 common sixweeksgrass 30%
Kentucky bluegrass 30%
slender wheatgrass 15%
baltic rush 10%
common snowberry 5%
fringed sagewort T
squirrel tail T
3 baltic rush 80%
common snowberry]
woods rose j
Kentucky bluegrass
slender wheatgrass
fringed sagewort
needle-and-thread
silver sagebrush
fringed sagewort
slender wheatgrass
blue grama
30%
20%
T
35%
20%
5%
5%
T
A-32
FIGURE 22
NORTH FORK BURNS CREEK
-------
Location shown on
Plate 22, Enid SE
-avf
1 wheat
2 woods rose 30%
Kentucky bluegrass 25%
fescue 8-10%
big bluestern 5%
Canada wildrye 5%
common snowberry T
sunflower T
silver sagebrush T
crested wheatgrass T
slender wheatgrass T
3 same as 2 with
common snowberry
5%
FIGURE 23
MIDDLE FORK BURNS CREEK
A-33
-------
Location shown on
Plate 20, Clay Butte
wildlife
habitat
1 wheat
broom snakeweed
prairie sand reedgrass
yellow sweetclover
little bluestem
buffaloberry
wild licorice
3 woods rose ]
biiffaloberryj
Kentucky bluegrass
smooth brome
'30%
25%
20%
20%
T
T
sedges
reeds
foxtail barley
Kentucky bluegrass 70%
prairie sand reedgrass 20%
buffaloberry 5-10%
thimothy T
thistle T
goosefoot T
slender wheatgrass T
Kentucky bluegrass 25%
prairie sand reedgrass 20%
horsetail 20%
yellow sweetclover 15%
slender wheatgrass 15%
little bluestem 5%
thistle T
thimothy T
fringed sagewort T
goosefoot T
7 prairie sand reedgrass 50%
blue grama 30%
Kentucky bluegrass 15%
broom snakeweed 5%
junegrass 3-4%
T
T
FIGURE 24
NORTH FORK
THIRTEENMILE CREEK
-------
H
H'
Location shown on
Plate 20, Clay Butte
avf
prairie sand reedgrass 40%
yellow sweetclover 25%
little bluestem 20%
alkali sacaton 10%
forbs T
horsetail T
junegrass T
woods rose T
2 rush 90%
switch panicgrass 25%
dropseed 25%
forbs 25%
slender wheatgrass 20%
little bluestem 5%
slender wheatgrass 50%
switch panicgrass 20%
dropseed 5%
common snowberry swards
forbs T
5 prairie sand reedgrass 60%
hairy golden aster 15%
little bluestem 12-15%
juniper T
6 wheat
FIGURE 25
NORTH FORK
THIRTEENMILE CREEK
A-35
-------
Location shown on
Plate 22, Enid SE
avf-
1 blue gramma 90%
broom snakeweed 5%
fringed sagewort T
2 western wheatgrass 95%
broom snakeweed 5%
sandberg bluegrass 40%
western wheatgrass 40%
little bluestem 3%
switch panicgrass T
common snowberry T
curlycup gumweed T
American sloughgrass 60%
sedges 10%
Canada wildrye T
little bluestem T
woods rose T
5 American sloughgrass 50%
curly dock 40%
6 woods rose
common snowberry
90%
6 little bluestem T
Canada wildrye T
western wheatgrass T
7 western wheatgrass 80%
blue grama 15%
broom snakeweed T
wild licorice T
8 wheat
FIGURE 26
SOUTH FORK BURNS CREEK
A-36
-------
Location shown on
Plate 28, Larson School
-avf-
1 prairie cordgrass
slender wheatgrass 80%
switch panicgrass 10%
hairy golden aster 5%
prairie cordgrass T
woods rose T
common snowberry T
rush 95%
Kentucky bluegrass T
reed canarygrass T
hairy golden aster T
blue grama 60%
western wheatgrass 30%
slender wheatgrass T
curlycup gumweed T
A-37
FIGURE 27
CRANE CREEK
-------
K
Location shown on
Plate 30, Crane
K'
40% bare ground
30 '/<> gravel
blue grama 95%
sideoats grama 5%
sandberg bluegrass 5%
broom snakeweed 5%
western wheatgrass 5%
blue grarna 50%
prairie sand reedgrass 10-15%
sideoats grama 10%
little bluestem 5%
red threeawn 2-3%
brome snakeweed T
yucca T
curlycup gumweed T
western wheatgrass I
needle-and-thread T
blue grama 90%
western wheatgrass 5%
cudweed sagewort T
fringed sagewort T
blue grarria 50%
cudweed sagewort 45%
needle-and-thread 4-5%
woods rose T
5 needle-and-thread
hairy golden aster
woods rose
western wheatgrass 60%
blue grama 30%
needle-and-thread 10%
little bluestem T
woods rose T
plains prickly pear T
club moss T
red threeawn T
little bluestem 50%
blue grama 45%
sideoats grama T
prairie sand reedgrass T
woods rose T
broom snakeweed T
6 blue grama 50%
fringed sagewort 50%
prairie sand reedgrass swards
woods rose swards
FIGURE 28
DUNLAP CREEK
A-33
-------
Location shown on
Plate 30, Crane
L'
avf
1 western wheatgrass 30%
blue grama 25%
prairie sand reedgrass 25%
fringed sagewort 4%
hairy golden aster T
horsetail T
prairie cordgrass T
woods rose T
dropseed 50%
switch panicgrass 30%
prairie cordgrass 5%
slender wheatgrass 5%
blue grama 5%
curlycup gumweed 2-3%
yellow sweetclover 40%
horsetail 25%
Canada wildrye 5%
rose T
prairie cordgrass T
wild licorice T
curlycup gumweed T
fringed sagewort T
squirrel tail T
western wheatgrass 30%
Canada wildrye 20%
green bristlegrass T
prairie cordgrass T
buffaloberry T
forbs T
blue grama 45%
little bluestem 25%
prairie sand reedgrass 5%
horsetail 2-3%
yellow sweetclover T
Canada wildrye T
western wheatgrass T
fringed sagewort T
pussytoes T
buffaloberry T
switch panicgrass T
Other areas, same
dropseed ,
switchgrass
buffaloberry
slender wheatgrass
little bluestem
prairie cordgrass
terrace
45%
30%
20%
10%
swards
T
blue grama
western wheatgrass
prairie sand reedgrass
horsetail
fringed sagewort
woods rose
7 blue grama
western wheatgrass
60%
30%
5%
T
T
T
60%
FIGURE 29
SEARS CREEK
A-39
-------
APPENDIX II
Area 2. Wei don - Timber Creek Deposit
A-40
-------
LEGEND
1:76,000 aerial
(Plates 1-8)
photographs
Weldon-Timber Creek Deposit
A11uvial Val1ey FToors. These are mapped as the low terrace, floodplain,
and channel of major drainages and those minor drainages whose low terraces
are either used in part for hay production or which have the potential for
such use. These areas may include soils which have potential salinity pro-
blems. Areas less than 15 m wide are excluded (see text).
Strippable Coal Deposits (Matson, 1970)
under less than 46 m of overburden.
Denotes area of the "S" coal seam
Nominated BLM Lands for Coal Leasing (BLM, 1976). Lands nominated in 1976
for leasing by Bureau of Land Management for coal development; shown only
beyond the limits of indicated strippable coal (Matson, 1970) to suggest
additional area of coal resource.
H
Hayed Lands. Lands where hay was observed to be harvested,
irrigated for that purpose. Irrigated lands mapped by the
and lands
Montana Water
Resources Board (1971b) and lands appraised as wild hay land under the
Montana Agricultural Land Classification.
A-41
-------
Location of Saline Soils. Where valley soils were mapped as "typic
fluvaquents, 0-2% slopes, saline. Tend to have surface and subsurface
gypsum crystals", or be the Alona series soils which have a moderately
alkaline surface, moderately to strongly alkaline subsoils, and strongly
alkaline parent material. (Strom, in progress) Includes observed salt
crusts where soil survey data unavailable.
A-42
-------
N
PLATE 1 TIMBER CREEK (HREA 2)
-------
N
PLATE 2 SKULL AND TIMBER CREEKS G;-\REA 2)
-------
. 4i: >
N
PUTE 3 JELSON CREEK WEST (*REA 2)
-------
PLATE 4 SKULL CREEK (AREA 2)
-------
N
PLATE 5 McGuiRE CREEK (AREA 2)
-------
N
PLATE G .JELSON CREEK LAST (AREA 2)
/Hid
-------
N
PLATE 7 DIRTY CREEK (MREA 2)
-------
N
PLATE b HORSE AND PRAIRIE ELK CREEK (AREA 2)
A-50
-------
APPENDIX III
Area 3. Redwater River Deposit
A-51
-------
LEGEND
1:76,000 aerial photographs
(Plates 9 - 19)
Redwater River Deposit
Alluvial Valley Floors. These are mapped as the low terrace, floodplain,
and channeT of major drainages and those minor drainages whose low ter-
races are either used in part for hay production or which have the poten-
tial for such use. These areas may include soils which have potential
salinity problems. Areas less than 15 m wide excluded (see text).
Related Alluvial Deposits. Dashed lines show upper boundaries of
higher alluvial deposits along Redwater River. Includes recent (?)
alluvial deposits of the Redwater River. Includes surface colluvium pro-
bably underlain by alluvium.
Strippable Coal Deposits (Matson, 1970).
under less than 46 m of overburden.
Denotes area of the "S" coal seam
Nominated BLM Lands for Coal Leasing (BLM, 1976). Lands nominated in 1976
for leasing by Bureau of Land Management for coal development; shown only
beyond the limits of indicated strippable coal (Matson, 1970) to suggest
additional areas of coal resource.
A-52
-------
H
Hayed Lands. Lands where hay was observed to be harvested, and lands irri-
gated for that purpose. Irrigated lands mapped by the Montana Water Resources
Board (1971b) and lands appraised as wild hayland under the Montana Agricultural
Land Classification.
Location of Saline Soils.
Where valley soils were mapped as "typic fluvaquents,
Tend to have surface and subsurface gypsum crystals", or
soils which have a moderately alkaline surface, moderately
0-2% slopes, saline.
to strongly alkaline subsoils, and strongly alkaline parent material (Strom,
in progress). Includes observed salt crusts where soil survey data unavailable.
Location of Transect. (See Figures 30-33). Fiducial marks indicate terminal
points of measurements.
A-53
-------
N
PUVTE 9 HORSE CREEK (AREA 5)
-------
KEDWATBRi RIVER
PUTE 10 TIMBER AND JRY ASH CREEKS (AREA 3)
A-55
-------
N
PLATE II Cow CREEK WEST (AREA 3)
A-56
-------
N
PLATE 12 BUFFALO CREEK (AREA 3)
-------
jfl
Mfilt*^
pl|(Hlffl!fi!i.- '. iUi'l
N
PLATE 13 LOST AND BUFFALO SPRINGS CREEJ:
(AREA :
A-5o
-------
N
PLATE m McCuNE CREEK (AREA
-------
PLATE ]5 Cow CREEK LAST (MREA 3)
-------
N
PLATE 16 DUCK AND SPRING CREEKS (/AREA 3)
A-61
-------
PLATE 17 COTTONWOOD CREEK (AREA 3)
A-62
-------
N
PLATE io BERRY CREEK (HREA 3)
-------
\QEDtfAfBR RIVER
PLATE 19 BLUFF CREEK (AREA 3)
-------
TRANSECTS
Transects M - M1 through P - P' Redwater River Deposit
Legend
•OO'MORZ.
C*>"*>
10*
vmt
(S*>
Highest evidence of flood flow (where found)
indicated by fiducary marks on either side
of channel.
Location of vegetation survey. Observations
below transect are in terms of percent of
total vegetative cover each species comprises.
Descriptions are for a band fifteen meters
wide along transect.
(transects based on pace and compass measurements,
not surveys)
Scale
A-65
-------
Location shown on Plate 13
Lost and Buffalo Springs Creeks
M
1 blue grama 75%
western wheatgrass 25%
silver sagebrush T-40%
needle-and-thread T
curlycup gumweed T
cudweed sagewort T
hairy golden aster T
2 Canada wild rye 40%
Kentucky bluegrass 30%
yellow sweetclbver 20%
switch panicgrass 10%
fringed sagewort T
wild licorice T
rose T
cudweed sagewort T
crested wheatgrass T
baltic rush 90%
switch panicgrass T
Canada wildrye 65%
slender wheatgrass 20%
switch panicgrass 10%
prairie cordgrass T
horsetail T
wild licorice T
prairie sand reedgrass 60%
western wheatgrass 25%
yellow sweetclover 5%
switch panicgrass 3%
wild licorice T
cudweed sagewort T
woods rose T
Canada wildrye T
Kentucky bluegrass T
6 western wheatgrass 45%
silver sagebrush 20%
prairie sand reedgrass 15%
blue grama 10%
needle-and-thread 5%
woods rose T
fringed sagewort T
clubmoss T
broom snakeweed T
hairy golden aster T
yellow sweetclover T
common snowberry T
7 blue grama grass
v/estern wheatgrass 25%
silver sagebrush T
broom snakeweed T
hairy golden aster T
fringed sagewort T
clubmoss T
yellow sweetclover T
FIGURE 30
REDWATER RIVER
A-66
-------
Location Shown on Plate 10
Timber and Dry Ash Creeks
1 wheat
2 crested wheatgrass 70%
blue grama , 20%
needle-and-thread 5-8%
western wheatgrass T
3 (high areas)
blue grama 70%
western wheatgrass 20%
needle-and-thread 10%
silver sagebrush T
3 (low areas)
prairie sand reedgrass 50%
blue grama 20%
needle-and-thread 20%
western wheatgrass 10%
little bluestem T
crested wheatgrass T
horsetail T
avf
4 blue grama
needl e-and-thread
prairie sand reedgrass
horsetail
switch panicgrass
crested wheatgrass
silver sagebrush
prairie sand reedgrass
yellow sweet clover
crested wheatgrass
silver sagebrush
blue grama
horsetail
6 yellow sweetclover
switch panicgrass
slender wheatgrass
7 baltic rush
40%
30%
30%
T
T
T
T
70%
25%
T
T
T
T
10
95%
switch panicgrass 40%
Kentucky bluegrass 25%
prairie sand reedgrass 20%
yellow sweet clover 10-15%
Canada wildrye . T
common snowberry T
crested wheatgrass 100%
Kentucky bluegrass T
silver sagebrush T
cudweed sagewort T
prairie sand reedgrass 25%
Kentucky bluegrass 20%
blue grama 20%
western wheatgrass 15%
silver sagebrush 10%
crested wheatgrass 10%
cudweed sagewort T
15
11 blue grama 100%
fringed sagewort T
silver sagebrush T
12 wheat
13 crested wheatgrass 952»
blue grama 5%
silver sagebrush T
14 western wheatgrass 35%
crested wheatgrass 25%
silver sagebrush 15%
common snowberry 10%
needle-and-thread 10%
green needlegrass T
broom snakeweed T
15 blue grama 50%
western wheatgrass 50%
dropseed T
crested wheatgrass T
silver sagebrush T
fringed sagewort T
needle-and-thread T
broom snakeweed T
slender wheatgrass T
rubber rabbitbrush T
14
FIGURE 31
REDWATER RIVER
A-67
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Location shown on Plate 10
Timber and Dry Ash Areeks
gravel
20% 5%
O'
avf
1 needle-and-thread 75%
blue grama 25%
silver sagebrush T-5%
2 needle-and-thread 80%
blue grama 10%
cudweed sagewort 5%
silver sagebrush 2-3%
yellow sweetclover T
horsetail T
western wheatgrass 60%
needle-and-thread 30%
silver sagebrush 5%
Kentucky bluegrass T
sandberg bluegrass T
fringed sandwort T
Kentucky bluegrass 75%
inland saltgrass 25%
horsetail T
yellow sweetclover T
slender wheatgrass T
silver sagebrush T
switch panicgrass T
Canada wildrye T
baltic rush 90%
slender wheatgrass T
curlycup gumweed T
prairie cordgrass T
6 inland saltgrass 45%
needle-and-thread 35%
yellow sweetclover 20%
silver sagebrush T
switch panicgrass T
blue grama 50%
needle-and-thread 30%
western wheatgrass 10%
prairie sand reedgrass 10%
silver sagebrush 3%
blue grama 80%
needle-and-thread 20%
western wheatgrass T
silver sagebrush T
FIGURE 32
REDWATER RIVER
A-68
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Location shown on Plate 13
Lost and Buffalo Springs Creeks
P'
avF-
wet
1 blue grama 90%
inland saltgrass 7%
western wheatgrass 3%
2 inland saltgrass 95%
western wheatgrass T
inland saltgrass 80%
blue grama 10%
wild licorice T
switch panicgrass T
silver sagebrush T
slender wheatgrass T
Kentucky bluegrass T
sedges T
blue grama 50%
needle-and-thread 25-30%
western wheatgrass 20%
silver sagebrush T-3%
broom snakeweed T
woods rose T
buffaloberry T
fringed sagewort ... T
curlycup gumweed JT
plains prickly pear (T
blue grama
western wheatgrass '5%
needle-and-thread 243%
silver sagebrush JT
broom snakeweed T
fringed sagewort T
plains prickly pear T
A-69
FIGURE 33
HORSE CREEK
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APPENDIX IV
Area 4. Eastern Garfleld County
A-70
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LEGEND
1:24,000 topographic maps
(Figures 14-17)
Eastern Garfield County
Alluvial Valley Floors. These are mapped as the low terrace, floodplain, and
channel of major drainages and those minor drainages whose low terraces are
either used in part for hay production or which have the potential for such
use. These areas may include soils which have potential salinity problems.
Areas less than 15 m excluded.
Related Alluvial Deposits. Recent (?) alluvial deposits of streams whose
lowest terraces are mapped as alluvial valley floors. Includes surface
colluvium probably underlain by alluvium.
Nominated BLM Lands for Coal Leasing (BLM, 1976). Lands nominated in 1976
for leasing by Bureau of Land Management for coal development.
Hayed Lands. Lands where hay was observed to be harvested and lands irrv
gated for that purpose. Irrigated lands mapped by the Montana Water Re-
sources Board (unpublished).
A-71
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Salt Crusts. Surface salt crust observed in field or on air photos,
A-72
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UNTOD VTATU
anamaHT or TMC Krone*
OEOUX1ICAL SIMVEY
EASTERN GARFIELD COUNTY
FIG, M LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
HEDSTROM LAKE NW AND HEDSTROM LAKE QUADRANGLES, MT
A-73
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UNITED STATES
DEPARTMENT OF THE INTERIOR
GEOLOGICAL SURVEY
EASTERN GARFIELD COUNTY
FIG, 15 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
TREE COULEE SCHOOL AND HEDSTROM LAKE SE QUADRANGLES, MT
A-74
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UWTED STATES
DEPARTMENT OF THE INTERIOR
OEOL001CAL SURVEY
EASTERN GARFIELD COUNTY
FIR, 16 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
LITTLE CHALK BUTTE AND CROW ROCK QUADRANGLES., MT
A-75
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UMTU tTATM
vtnamam or -nil ammo*
onwa
EASTERN GARFIELD COUNTY
FIG, 17 LOCATION OF ALLUVIAL VALLEY FLOORS AND RELATED FEATURES
ROCK SPRINGS SCHOOL AND CROW ROCK SE QUADRANGLES, MT
A-76
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COMMON AND SCIENTIFIC NAMES OF VEGETATION FOUND IN STUDY AREAS1
Alkali cordgrass
Alkali sacaton
Alkaligrass
American bull rush
American sloughgrass
American vetch
Baltic rush
Big bluestem
Blue flax
Blue grama
Bluegrass
Broom snakeweed
Buffaloberry
Canada wildrye
Cheatgrass brome
Clubmoss
Common dandelion
Common milkweed
Common salsify
Common sixweeksgrass
Common snowberry
Cordgrass
Creeping juniper
Crested wheatgrass
Cudweed sagewort
Curly dock
Curlycup gumweed
Dropseed
Fescue
Foxtail barley
Fringed sagewort
Goosefoot
Green bristlygrass
Hairy golden aster
Horsetail
Indian ricegrass
Inland saltgrass
Junegrass
Juniper
Kentucky bluegrass
Kochia
Little bluestem
Mustard
Nuttall Saltbush
Apartina gracilis
SporoboTus airoTcfes
Pucinellia airoides
Scirpus americanus
Beckmannia svzigachne
Vicia americana
Juncus balticus
Andropoqon qerardii
Linum perenne
Boutelous gracilis
Poa spp.
Gutierrezia sarothrae
Sheperdia argentea
Elymus canadensis
Bromus tectorum
Lvcopodium
Taraxacum officinale
Asclepius syriaca
Tragopagon dubius
Vulpia octoflora
Symphoricarpus albus
Spartina spp.
Juniperus horizontal is
Agropvron cristatum
Artemesia ludoviciana
Rumex crispus
Grindelis squarrosa
Sporobolus spp.
Festuca spp.
Hordeum .iu bat urn
Artemesia friqida
Chenopodiaceae
Setaris viridis
Chrvsopsis villosa
Equisetum spp.
Orvzopsis hvmenoides
Distich!is stricta
Koeleria cristata
Juniperus spp.
Poa pretensis
Kochia scoparia
Andropogon scoparius
Cruciferae
Atriplex nuttallii
Booth, W. E. 1972. Grasses
Boseman, MT. 305pp.
Booth, W.E. and J.C. Wright.
Montana State University,
of Montana. Montana State University,
1966. Flora of Montana, dicotyledons
Bozeman, MT. 305pp.
A-77
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Prairie cordgrass
Prairie sand reedgrass
Pussytoes
Quackgrass
Red threeawn
Reed canarygrass
Rough false pennyroyal
Rubber rabbitbrush
Rushes
Sandberg bluegrass
Scarlet globemallow
Sedge
Sideoats grama
Silver sagebrush
Slender wheatgrass
Small leaf pussytoes
Smooth brome
Squirrel tail
Still stem flax
Sunflower
Switch panicgrass
Thimothy
Thistle
Treadleaf sedge
Tumble grass
Western wheatgrass
Western yarrow
White milkwort
Wild licorice
Willow
Woods rose
Yellow sweetclover
Yucca
Spartina pectinata
Calamovilfa longifolia
Antennaria spp.
AgropyronTrepens
Aristada lonaiseta
Phalaris arundinacea
Hedeoma hispida
Chrvsothamnus nauseosus
Juncus spp.
Poa secunda
Sphaeralcae coccinea
Carex spp.
Bouteloua curtipendula
Artemesia cana
Agrpyron trachvcaulum
Antennaria parviflora
Bromus inermis
Sitanion hvstrix
Linum rigidum
Helianthus spp.
Panicum virgatum
Phleum pratensis
Carduus spp.
Carex fillifolia
Schedonnardus paniculatis
Agropyron smithii
Achillea lanulosa
Polvgala alba
Glvcvrrhiza lipidota
Salix_ spp.
Rosa woodsii
Melilotus officinal is
Yucca^ spp.
A-78
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing/
1. REPORT NO.
OEA 76-1
3. RECIPIENT'S ACCESSIOf»NO.
4. TITLE AND SUBTITLE
ALLUVIAL VALLEY FLOORS IN EAST-CENTRAL MONTANA AND
THEIR RELATION TO STRIPPABLE COAL RESERVES
Reconnaissance report
5. REPORT DATE
January 1977
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Jack Schmidt
8. PERFORMING ORGANIZATION REPORT NO.
OEA 76-1
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Montana Department of Natural Resources
Water Quality Bureau and
Montana Energy Advisory Council
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Enerqv Activities
1860 Lincoln St., Suite 10
Denver, Colorado 80295
13. TYPE OF REPORT AND PERIOD COVERED
Information 1976
14. SPONSORING AGENCY CODE
EPA - Region VIII
15. SUPPLEMENTARY NOTES
16. ABSTRACT
This reconnaissance study indicates that small percentages of
strippable coal underlie the valley floors of east central Montana.
Extensive coal reserves underlie upland areas and small tributary streams.
Valley floors serve an important role in the local economy and are the
most productive lands of the region. They are primarily high-quality
sources of range forage and secondarily produce harvestable hay crops.
Stream channels, floodplains, and low terraces were mapped as
alluvial valley floors in those valleys used for hay production or which
appeared to have the potential for such use. This mapping is considered
to be consistent with the previous work of Malde and Boyles (1976) and
the Environmental Protection Agency (1976). Alluvial valley floors
overlie 1.5 percent of the tonnage of high potential development coal
reserves of the Burns Creek-Thirteenmile Creek Known Coal Leasing Area
(KCLA), Dawson and Richland Counties; 2.4 percent of the tonnage of the
Weldon-Timber Creek strippable coal deposit, western McCone County; and
8 percent of the tonnage of the Redwater River strippable coal deposit,
eastern McCone County. Mapping of the more extensive high terraces along
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COS AT I Field/Group
Agriculture Surface mining
Alluvium Soil
Alluvial Valley Floors Vegetation
Coal Reclamation
Geology
Grazing
Hydrology
18. DISTRIBUTION STATEMENT
Release to Public
19. SECURITY CLASS (ThisReport)
Unclassified
21. NO. OF PAGES
80
20. SECURITY CLASS (Thispage)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
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alluvial valley floors in the Burns Creek-Thirteenmile Creek KCLA and
the Redwater River deposit show that about twice as much coal underlies
the total alluvial deposit area than underlies the more restrictively
defined alluvial valley floor. If mining were excluded in the total
alluvial valley floor area, an even greater percentage of reserves would
be made unavailable because of the impracticality of developing logical
mining units. Despite this fact, extensive strippable coal reserves exist
in each area studied in this report, outside of valley floor areas.
Various characteristics of valley floor areas were mapped and
vegetation was investigated along several transects in the Burns Creek-
Thirteenmile Creek KCLA and in the Redwater River area. These data show
that valley floors support distinctive vegetative communities (species
lists are included in the report) and produce the most forage of any
range sites in the area. Soil salinity is the most important factor
limiting use of valley floors, particularly in McCone and eastern Garfield
Counties, and also may pose a significant challenge to mining reclamation.
This work supports conclusions of previous investigations in demon-
strating that the quasi land use category of alluvial valley floors can
be mapped by combining topographic maps, selected aerial photography,
and reconnaisance field work. This work identifies the alluvial valley
floor as a part of a larger mappable geologic unit which includes the
alluvial deposits extending out from the alluvial valley floors and
While it remains evident that more detailed hydrologic, geologic, and en-
gineering work is necessary to identify the specific impacts of a mining opera-
tion on a particular valley floor, this effort shows that it is possible to use
reconnaissance methods to identify and map those valley floors of agriculture
and hydrologic significance. Future reconnaissance mapping efforts should focus
on valleys used in part for hay production since most all alluvial valley floors
mapped in this study contain some areas of hay production. It is estimated that
25 percent of all mapped alluvial valley floors were in hay production at the
time of the field investigations. Those areas mapped as related alluvial depo-
sits included most of the remaining hay lands.
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* U.S. Government Printing Office: 1977-778-495/134 Region 8
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