BLEED
A Summary of the U.S. Geological Survey 1999

Resource Assessment of Selected Coal Zones in the 

Northern Rocky Mountains and Great Plains Region, 

Wyoming, Montana, and North Dakota

By M.S. Ellis and D.J. Nichols

U.S. Geological Survey Bulletin 2189

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

Version 1.0

2002

This publication is only available online at:

http://geology.cr.usgs.gov/pub/bulletins/b2189/

Any use of trade, product, or firm names in this publication

is for descriptive purposes only and does not

imply endorsement by the U.S. Government
Contents

Abstract............................................................................................................................................................ 1

Introduction ..................................................................................................................................................... 1

Coal Assessed................................................................................................................................................. 2

Geologic Setting.............................................................................................................................................. 2

Coal Quality...................................................................................................................................................... 4

Coal Resources ............................................................................................................................................... 4

Conclusions ..................................................................................................................................................... 8

References Cited ............................................................................................................................................ 8

Figures

1. Map showing major coal basins in conterminous United States...................................................... 1

2. Map showing coal basins in Northern Rocky Mountains and Great Plains region ....................... 3

3. Diagram showing biostratigraphic (palynostratigraphic) zonation of the Paleocene 

and adjacent rocks in Rocky Mountain region ............................................................................ 5

4. Generalized sections showing relative age, thickness, and stratigraphic relationship

of coal assessed for the National Coal Resource Assessment in Northern

Rocky Mountains and Great Plains region ................................................................................... 6

5. Diagram showing how lithologic data are interpreted to determine net coal thickness

at each data point location.............................................................................................................. 7

6. Index map showing coal fields studied for National Coal Resource Assessment in

Northern Rocky Mountains and Great Plains region .................................................................. 8

7. Map showing surface management of land in Northern Rocky Mountains

and Great Plains region.................................................................................................................... 9

8. Diagram of coal resources for assessed coal in Northern Rocky Mountains and

Great Plains region reported by Federal and non-Federal surface management

and coal ownership .......................................................................................................................... 9

Tables

1. Coal production from Wyoming, Montana, and North Dakota in 1999 ............................................. 2

2. Coal basins, coal fields, assessment units, and coal beds included in the

Northern Rocky Mountains and Great Plains region coal resource assessment.................. 4

3. Average total sulfur content and ash yield, pounds of SO2 per million Btu,

and calorific value of assessed coal ............................................................................................. 6

4. Coal resources reported by coal field.................................................................................................... 7
Abstract

In 1999, 1,100 million short tons of coal were produced 

in the United States, 38 percent from the Northern Rocky 

Mountains and Great Plains region. This coal has low ash 

content, and sulfur content is in compliance with Clean Air Act 

standards (U.S. Statutes at Large, 1990).

The National Coal Resource Assessment for this region 

includes geologic, stratigraphic, palynologic, and geochemical 

studies and resource calculations for 18 major coal zones 

in the Powder River, Williston, Green River, Hanna, and 

Carbon Basins. 

tons. 

Survey Professional Paper 1625–A (Fort Union Coal Assessment Team, 1999) and Open-File Report 99-376 (Flores and 

others, 1999) in CD-ROM format. 

Introduction

The U.S. Geological Survey (USGS) assessed coal 

resources in the conterminous United States to determine the 

quantity, quality, and minability of coal that is likely to be 

produced within the next 20-30 years. The National Coal 

Resource Assessment (NCRA) included studies of coal in fi ve 

regions—the Northern Rocky Mountains and Great Plains (fi g.

1), the Colorado Plateau, the Illinois Basin, the Gulf Coast, 

and the Appalachian Basin.

The Northern Rocky Mountains and Great Plains region 

contains an abundance of coal with a high potential for development. 

production was from Wyoming, Montana, and North Dakota 

(table 1). Coal in the region is generally low in total sulfur and 

ash content and compliant with Clean Air Act standards for use 

in coal-fired power plants. 

more than the equivalent of 1.24 lb of SO2 per million Btu be 

released in flue emissions (U.S. Statutes at Large, 1990). 

The coal assessment in the Northern Rocky Mountains 

and Great Plains region covered 18 priority coal assessment 

units in five coal basins (fig. 2). In addition to the resource 

calculations, the project included local and regional geologic, 

stratigraphic, palynologic, and coal-geochemical studies. Objectives of the NCRA in this region were to compile all 

pertinent information on the selected coal beds, identify clean 

and compliant coal in the region, compile a publicly available 

digital database, and publish spatial digital products in a 

variety of interpretive and interactive forms. 

Final products for the assessment include two CDROMs that present the results of the study in a variety of formats. These CD-ROMs contain resident software for viewing, printing, querying, and downloading text, graphics, spatial layers, and raw data (Fort Union Coal Assessment Team, 

1999; Flores and others, 1999). 

A Summary of the U.S. Geological Survey 1999

Resource Assessment of Selected Coal Zones in the 

Northern Rocky Mountains and Great Plains Region, 

Wyoming, Montana, and North Dakota

By M.S. Ellis and D.J. Nichols

Other coal basins

Coal basins in the

Northern Rocky Mountains

and Great Plains region 

EXPLANATION

Figure 1. Major coal basins in conterminous United States.

Calculated resources are 660,000 million short 

Results of the study are available in U.S. Geological 

In 1999 more than 38 percent of national coal 

Current standards require that no 
2 Selected Coal Zones, Northern Rocky Mountains and Great Plains Region 

Coal Assessed 

Coal assessment units in the Northern Rocky Mountains 

and Great Plains region included the Wyodak-Anderson, Anderson-Canyon, Rosebud-Robinson, and Knobloch coal in the 

Powder River Basin of Wyoming and Montana; the Harmon, 

Hansen, Beulah-Zap, and Hagel coal in the Williston Basin; 

the Deadman coal in the Greater Green River Basin, and 

the Ferris, Hanna, and Johnson-107 coal in the Hanna and 

Carbon Basins (fig. 2). The assessment units and the coal 

beds within the assessment units are shown in table 2. Coal 

in the Bighorn, Bull Mountain, Denver, North Park, Raton, 

and Wind River Basins was not assessed in detail for this 

study, because it has a lower potential for development. These 

basins are discussed in a general manner in the final report 

(Chapters SB, SM, SD, SN, SR, and SW in Fort Union Coal 

Assessment Team, 1999). 

Geologic Setting 

Coal assessed for this study occurs in basins of Tertiary 

age. The coal developed from peat that was deposited in 

swamps adjacent to fluvial drainages during middle to late 

Paleocene time. Palynologic time zones have been identified, 

based on palynostratigraphy, for the coal assessed (Nichols, 

1994, 1999; Fort Union Coal Assessment Team, 1999) (figs. 3, 

4). Biozones were identified using fossil pollen and spores that 

occur only in certain intervals in lower Eocene, Paleocene, and 

Upper Cretaceous rocks. The palynologic biozones were used 

to define the age of individual coal beds and other lithologic 

units for stratigraphic correlation and to aid in determining 

which beds were to be included in the priority assessment units. 

The environments of deposition of peat in the Northern 

Rocky Mountains and Great Plains region differed in detail in 

the four basins, although the primary environment of deposition in the basins was fluvial, with drainage generally flowing 

to the northeast or the east. The thickness of peat accumulation, amount and type of detritus in the peat, lateral variability 

of the beds, and apparent rank (as defined by American Society 

for Testing and Materials, 1999) of the coal were dependent 

on the environment of deposition of the peat and subsequent 

factors affecting the coalification. Some of the factors affecting the coal characteristics were the rate of subsidence of the 

basin, the dynamics of the drainage system, the proximity of 

the swamp to the origin or the terminus of the drainage, the 

susceptibility of the peat swamp to flooding, and the location 

of sediment source areas. 

Thick peat accumulated in deep portions of the Powder 

River Basin where the basin was rapidly subsiding. During 

middle to late Paleocene time much of the peat accumulated in 

raised bogs, which led to the formation of coal that was thick 

and contained little clastic detritus. Although the coal beds 

in the Wyodak-Anderson coal zone are relatively thick, they 

are not laterally continuous because braided, meandering, and 

anastomosed rivers cut through and eroded away portions of 

the peat swamps. The assessed coal in the basin is subbituminous in apparent rank. 

The Williston Basin was subsiding slowly, and therefore 

was shallower than the Powder River Basin during Paleocene 

time. Because the peat was not deeply buried, it has lower 

apparent rank than coal in the other basins. All of the 

assessed coal in the Williston Basin is lignite. Peat swamps 

were adjacent to slow-moving fluvial drainages that emptied 

into the Cannonball Sea. The beds are relatively thin, cut by 

channels, and contain large quantities of clastic detritus. 

The Hanna and Carbon Basins were surrounded by uplifts 

consisting of rocks of marine origin. These basins rapidly 

subsided subsequent to peat accumulation. Deep burial of the 

peat led to the formation of coal that is of higher apparent rank 

than coal in the other basins, subbituminous to bituminous. 

Coal that has been deeply buried has undergone a higher level 

of coalification caused by high temperature and high pressure. 

Higher level of coalification translates to higher calorific value 

and lower moisture content. The higher content of sulfur 

Table 1. Coal production from Wyoming, Montana, and North Dakota in 1999. 

[Modified from Freme and Hong (2000)] 

Area of production Coal production (In millions of short tons) 

Wyoming 335 

Montana 41 

North Dakota 30 

Total from these States 416 

Total from all of conterminous United States 1,094 
Geologic Setting 3 

1. River Basin 

2. 

3. 

4. eater Green River Basin 

5. 

6. 

7. 

8. 

9. Williston Basin 

MONTANA 

NEBRASKA 

NORTH 

DAKOTA 

SOUTH 

DAKOTA 

WYOMING 

NEW 

MEXICO 

8 

3 

6 

2 

5 

10 

1 

4 

7 

9 

COLORADO 

EXPLANATION 

Powder

Carbon Basin 

Denver Basin 

Gr

Hanna Basin 

North & Middle Park Basins 

Big Horn Basin 

Raton Basin 

10. Wind River Basin 

0 100 200 MILES Fort Union Formation and equivalent strata 

at the surface 

Fort Union Formation and equivalent strata 

in the subsurface 

Coal mine or lease areas 

Coal beds and zones 

Figure 2. Coal basins in Northern Rocky Mountains and Great Plains region. Basins indicated in bold type 

contain priority assessment units studied in detail for USGS coal assessment. 
4 Selected Coal Zones, Northern Rocky Mountains and Great Plains Region 

Table 2. Coal basins, coal fields, assessment units, and coal beds included in the Northern Rocky Mountains 

and Great Plains region coal resource assessment. 

Coal field / Assessment unit Coal beds in assessment unit 

Powder River Basin, Wyoming and Montana 

Wyodak-Anderson / Wyodak-Anderson 

Anderson, Dietz, Canyon, Monarch, Werner, Wyodak, 

Smith, Swartz, Sussex, School, and Badger 

Powder River Basin, Montana 

Decker/ Anderson-Canyon Anderson, Kirby, Dietz 1, 2, and 3, Cox, and Canyon 

Ashland/Knobloch Knobloch 

Colstrip/Rosebud-Robinson Rosebud, McKay, and Robinson 

Williston Basin, North Dakota 

Bowman-Dickinson / Harmon-Hansen Harmon and Hansen 

Beulah/Beulah-Zap Beulah-Zap 

Center-Falkirk/ Hagel Hagel 

Greater Green River Basin, Wyoming 

Black Butte–Point of Rocks/ Deadman Deadman 1-5 and A-C 

Hanna and Carbon Basins, Wyoming 

Ferris/Ferris Ferris 23, 25, 31, 50, and 65 

Hanna/Hanna Hanna 77, 78, 79, and 81 

South Carbon/ Johnson-107 Johnson, Finch, C106, and C107 

(table 3) in the coal is most likely caused by the influx of 

detritus derived from the marine rocks into peat swamps. 

The Deadman coal in the Greater Green River Basin 

formed in swamps that were probably low-lying and prone to 

floods by the braided and anastomosed rivers that meandered 

through them. The coal is of subbituminous apparent rank, 

contains moderately high ash content (table 3), and is laterally 

discontinuous. 

Coal Quality 

Coal in the Northern Rocky Mountains and Great Plains 

region is considered to be clean, low in contaminants, and 

compliant with 1990 Clean Air Act emission standards for 

acceptable levels of pounds of sulfur per million Btu from 

coal-fired power plants (U.S. Statutes at Large, 1990). Wyodak-Anderson coal from the Powder River Basin has the 

lowest mean content of pounds of SO2 per million Btu of any 

of the coal assessed for the NCRA (table 3). 

The apparent coal rank ranges from bituminous in the 

Hanna Basin, where it has been mined underground, to lignite 

in the Williston Basin, where it is surface mined. A more 

detailed description of coal quality for beds assessed for the 

NCRA is provided in Stricker and Ellis (1999a, b, c, and d). 

Coal Resources 

Data for this study were acquired through cooperation 

with the U.S. Bureau of Land Management, State geological 

surveys, U.S. Office of Surface Mining, and coal companies. 

The USGS National Coal Resource Data System (NCRDS) 

database was also a source of digital data. This database 

includes proprietary and public stratigraphic and lithologic 

information from coal and oil and gas exploratory drill holes, 

and measured sections at over 18,900 locations. Coal quality 

and coal geochemistry data were from the U.S. Geological 

Survey COALQUAL database (Bragg and others, 1994) and 
Coal Resources 5 

Caryapollenites 

veripites 

lower 

Eocene 

upper 

Paleocene 

middle 

Paleocene 

lower 

Paleocene 

Upper 

Cretaceous 

(part) 

Platycarya 

platycaryoides 

Caryapollenites 

Momipites 

species 

Wodehouseia spinata 

Assemblage 

P6 

P5 

P4 

P3 

P2 

P1 

Momipites 

ventifluminis 

Momipites 

actinus 

Momipites 

wyomingensis 

Figure 3. Biostratigraphic (palynostratigraphic) zonation of the Paleocene and adjacent rocks in Rocky Mountain 

region. Biozones are defined by occurrences of fossil pollen and spores (palynostratigraphy). “P” biozones of the 

Paleocene are defined by species of the related fossil pollen genera Momipites and Caryapollenites. 

from proprietary sources. The coal quality and coal geochemistry information consists of sample analyses from about 1,000 

data point locations. 

In the Northern Rocky Mountains and Great Plains 

region, most coal is discontinuous. Within short distances the 

beds are quite variable in thickness. Because of the lack of 

continuity of individual coal beds in this region, beds were 

grouped and correlated in zones. For coal resource calculations and categories, the thickness of the coal was represented 

by the net coal thickness in the zone (fig. 5). 

Coal beds, coal zones, and related rocks were correlated 

in a relational database. The assessment was organized by 

study areas or coal fields (fig. 6). The pertinent data were 

downloaded from the relational database and run through a 

custom program that uses the definition of partings and splits 

of Wood and others (1983) to determine the thickness of coal 

beds and calculate net coal thickness at each data point location (fig. 5). Net coal thickness does not include coal beds that 

are less than 2.5 ft thick. 

The net coal and overburden thickness was gridded 

and modeled using geologic modeling software, and the isopach maps were exported into geographic information system 

(GIS) software to generate polygon coverages. The layers of 

information (coverages) were then combined. The layers of 

information include not only the coal and overburden thicknesses but also land status, coal ownership, 7.5-minute quadrangle map areas, counties, clinker areas, and mine and lease 

areas. The union coverage, containing all attributes from each 

of the coverages, was used to calculate coal resources within 

each of the coverage polygons. Coal resource tables were 

produced from the final ASCII data output. The total coal 

resource numbers reported do not include areas extrapolated 

to contain net coal less than 2.5 feet thick, or coal in mine, 

lease, or clinker areas (Heffern and others, 1993; E.L. Heffern, 

Bureau of Land Management, oral and written commun., 

1998, 1999). This resource calculation does not take into 

consideration many of the economic, technological, cultural, 

and environmental restrictions to coal development. 

Coal resources were reported in tables using a variety of 

different parameters, including State, county, surface management, coal ownership, net coal thickness, overburden, reliability of the data (distance from a data point), and 7.5-minute 

quadrangle map area (Fort Union Coal Assessment Team, 

1999). Categories for coal thickness and overburden followed 

reporting standards for subbituminous or lignite apparent rank 

coal (Wood and others, 1983). Coal resources reported by coal 

field (fig. 6) and by surface management (fig. 7) are shown 

in table 4 and figure 8. The total resources (in millions of 
6 Selected Coal Zones, Northern Rocky Mountains and Great Plains Region 

Table 3. Average total sulfur content and ash yield, pounds of SO2 per million Btu, and calorific value of 

assessed coal. 

[Values for the Powder River Basin include only coal analyses from the Wyodak-Anderson coal zone] 

Coal basin Total sulfur content 

(percent) 

Ash yield 

(percent) 

SO 2 per million Btu 

(lb) 

Calorific value 

(Btu) 

Powder River 0.48 6.44 1.24 8,220 

Williston 0.84 7.96 2.54 6,510 

Greater Green River 0.56 11.18 1.27 9,000 

Hanna and Carbon 0.96 12.48 2.07 10,090 

WyodakAnderson 

and 

AndersonCanyon 

RosebudRobinson 

TERTIARY 

Paleocene 

Knobloch 

Ferris 

23, 25, 

31, 50

and 65 

Johnson107 

Hanna 

77, 78,

79, and 

81 

Deadman 

HarmonHansen 

BeulahZap 

Hagel 

Hanna Formation (part) Ferris Formation (part) 

Tullock 

Member 

Lebo 

Member 

Tongue 

River 

Member 

Ludlow 

Member 

Tongue 

River 

Member 

Sentinel 

Butte 

Member 

Fort 

Fort 

Fort 

P1 

P2 

P3 

P4 

P5 

P6 

P2 

P3 

P4 

P5 

P6 

P1 

P2 

P3 

P4 

P5 

P1 

P2 

P3 

P4 

P5 

P6 

P5 

Formation Union 

Formation Union 

Formation Union 

AGE POWDER RIVER 

BASIN WILLISTON BASIN GREATER GREEN 

RIVER BASIN 

HANNA AND 

CARBON BASINS 

Figure 4. Generalized sections showing relative age, thickness, and stratigraphic relationship of coal assessed for the National Coal Resource 

Assessment in Northern Rocky Mountains and Great Plains region. All coal assessed is Paleocene in age. Age of the coal is based on 

palynological biozones; “P” biozones 5 and 6 are late Paleocene; 3 and 4 are middle Paleocene; and 1 and 2 are early Paleocene (Nichols, 1994). 

(Modified from Fort Union Coal Assessment Team, 1999.) 
Coal Resources 7 

Wasatch/Fort Union? 

Rock (R) (p=parting, s=split) 

Fort Union Formation 

Fort Union Formation 

undifferentiated 

Coal (C) 

4 Coal thickness in feet 

4 C 

3 C 

78 Rs 

18 C 

70 Rs 

10 C 

3 Rs 

2 C 

161 Rs 

22 C 

4 Rp 

Number of coal beds = 5 

(the 2 ft bed was not included) 

Net coal thickness = 57 ft 

(includes beds > or equal to 

2.5 ft in thickness) 

Zone thickness = 375 ft 

Overburden thickness = 28 ft 28 R 

WyodakAnderson 

coal zone 

EXPLANATION 

STRATIGRAPHIC 

CORRELATIONS 

LITHOLOGIC 

COLUMN 

FINAL INTERPRETATION OF 

DATA USED FOR 

GEOLOGIC MODELING 

Figure 5. Diagram showing how lithologic data are interpreted to determine net coal thickness at each data point 

location. 

Table 4. Coal resources reported by coal field. 

[Resources are reported in millions of short tons (mst) rounded to two significant figures. Resources do not include coal in 

mine or lease areas, coal less than 2.5 ft thick, or coal in clinker areas] 

Basin State Coal field Coal resources (mst) 

Powder River 

Wyoming Wyodak-Anderson (WA) 550,000 

Montana 

Decker (also included in WA total) 45,000 

Ashland 6,000 

Colstrip 13,000 

Williston North Dakota 

Bowman-Dickinson 66,000 

Beulah 4,800 

Center-Falkirk 4,400 

Greater Green River Wyoming Black Butte–Point of Rocks 2,700 

Hanna and Carbon Wyoming 

Ferris 2,900 

Hanna 4,400 

South Carbon 1,100 
8 Selected Coal Zones, Northern Rocky Mountains and Great Plains Region 

108 ̊ 104 ̊ 

46 ̊ 

42 ̊ 

MONTANA 

SOUTH 

DAKOTA 

NORTH 

DAKOTA 

WYOMING 

0 50 100 

Hanna and 

Carbon Basins 

Greater Green River 

Basin (part) 

NEBRASKA 

Powder River Basin 

Williston 

Basin 

MILES 

EXPLANATION 

Coal fields 

Powder River Basin 

WyodakAnderson 

Ashland 

Colstrip 

Williston Basin 

Bowman-Dickinsen 

Beulah 

Center-Falkirk 

Greater Green River 

Basin 

Black Butte-Point 

of Rocks 

Hanna and Carbon 

Basins 

Ferris


Hanna


South Carbon


Tertiary coal basins

containing assessed

coal 

Figure 6. Index map showing coal fields studied for National Coal Resource Assessment in Northern Rocky 

Mountains and Great Plains region. 

short tons (mst) and rounded to two significant figures) for the 

coal assessed in each of the basin areas is 570,000 mst in the 

Powder River Basin; 76,000 mst in the Williston Basin, 2,700 

mst in the Greater Green River Basin, and 7,300 mst in the 

Hanna and Carbon Basins. 

Conclusions 

The National Coal Resource Assessment in the Northern 

Rocky Mountains and Great Plains region included detailed 

studies of selected coal beds. The total number of resources 

calculated for these coal beds and zones was about 660,000 

million short tons, 80 percent of which is Federally owned. 

The coal is generally low in contaminants and compliant with 

Clean Air Act emissions standards. Given the quantity and 

quality of coal in this region, the potential for continued development of coal that was assessed by this study, particularly in 

the Powder River Basin, is very high. 

References Cited 

American Society for Testing and Materials, 1999, Annual Book of 

ASTM Standards, Section 5, Petroleum products, lubricants and 

fossil fuels, Volume 05.05, Gaseous fuels; coal and coke: Philadelphia, Pa., American Society for Testing and Materials, 584 p. 

Bragg, L.J., Oman, J.K., Tewalt, S.J., Oman, C.L., Rega, N.H., Washington, P.M., and Finkelman, R.B., 1994, U.S. Geological Survey Coal 

Quality (COALQUAL) database: U.S. Geological Survey Open-File 

Report 94-205, Version 1.3, CD-ROM. 

Flores, R.M., Ochs, A.M., Stricker, G.D., Roberts, S.B., Ellis, M.S., 

Keighin, C.W., Murphy, E.C., Cavaroc, V.V., Jr., Johnson, R.C., and 

Wilde, E.M., 1999, National coal resource assessment non-proprietary data; Location, stratigraphy, and coal quality of selected 

Tertiary coals in the Northern Rocky Mountains and Great Plains 

region: U.S. Geological Survey Open-File Report 99-376, CD-ROM. 

Fort Union Coal Assessment Team, 1999, 1999 Resource assessment 

of selected Tertiary coal beds and zones in the Northern Rocky 

Mountains and Great Plains region: U.S. Geological Survey Professional Paper 1625–A, CD-ROM. 
Conclusions 

Bureau of Land Management 

National Park Service 

National Forest Service 

Other Federal Agencies 

State and private lands

Tribal lands 

EXPLANATION

MONTANA

WYOMING

NORTH 

DAKOTA

SOUTH 

DAKOTA

NEBRASKA

COLORADO

NEW

MEXICO

UTAH

IDAHO

1% 1%

14% 67%

9%

8%

 98,000

15%

560,000

85% 520,000 

80%

130,000

20%

0

100,000

200,000

300,000

400,000

500,000

600,000

Federal Non-Federal

Millions of short tons

Surface Management

Millions of short tons

Federal Non-Federal

Coal Ownership

0

100,000

200,000

300,000

400,000

500,000

600,000

COAL RESOURCES BY SURFACE MANAGEMENT

AND COAL OWNERSHIP

Figure 7. Surface management of land in Northern Rocky Mountains and Great Plains region.

Figure 8. Coal resources for assessed coal in Northern Rocky Mountains and Great Plains region 

reported by Federal and non-Federal surface management and coal ownership. 

rounded to two signifi cant figures. otals do not sum because of independent rounding of coal 

resources in each category. fied from U.S. Geological Survey, 2000.)

9

Coal resources are 

T

(Modi
10 Selected Coal Zones, Northern Rocky Mountains and Great Plains Region 

Freme, F.L., and Hong, B.D., 2000, U.S. coal supply and demand; 1999 

Review: Energy Information Administration, 8 p. 

Heffern, E.L., Coates, D.A., Whiteman, Jason, and Ellis, M.S., 1993, 

Geologic map showing distribution of clinker in the Tertiary Fort 

Union and Wasatch Formations, Northern Powder River Basin, 

Montana: U.S. Geological Survey Coal Investigations Map C–142, 

scale 1:175,000. 

Nichols, D.J., 1994, Palynostratigraphic correlation of Paleocene 

rocks in the Wind River, Bighorn, and Powder River Basins, Wyoming, in Flores, R.M., Mehring, K.T., Jones, R.W., and Beck, T.L., 

eds., Organics and the Rockies Field Guide: Wyoming State Geological Survey Public Information Circular 33, p. 17–29. 

Nichols, D.J., 1999, Stratigraphic palynology of the Fort Union Formation (Paleocene) in the Powder River Basin, Montana and Wyoming—A guide to correlation of methane-producing coal zones, in 

Miller, W.R., ed., Coalbed methane and the Tertiary geology of the 

Powder River basin, Wyoming and Montana: Wyoming Geological 

Association Fifteenth Field Conference Guidebook 1999, p. 25–41. 

Stricker, G.D., and Ellis, M.S., 1999a, Coal quality and geochemistry, 

Powder River Basin, Wyoming and Montana, Chapter PQ in Fort 

Union Coal Assessment Team, 1999 Resource assessment of 

selected Tertiary coal beds and zones in the Northern Rocky Mountains and Great Plains Region: U.S. Geological Survey Professional 

Paper 1625–A, CD-ROM disk 1. 

Stricker, G.D., and Ellis, M.S., 1999b, Coal quality and geochemistry, 

Hanna Basin, Wyoming, Chapter HQ in Fort Union Coal Assessment 

Team, 1999 Resource assessment of selected Tertiary coal beds 

and zones in the Northern Rocky Mountains and Great Plains 

Region: U.S. Geological Survey Professional Paper 1625–A, 

CD-ROM disk 1. 

Stricker, G.D., and Ellis, M.S., 1999c, Coal quality and geochemistry, 

Williston Basin, North Dakota, Chapter WQ in Fort Union Coal 

Assessment Team, 1999 Resource assessment of selected Tertiary 

coal beds and zones in the Northern Rocky Mountains and Great 

Plains Region: U.S. Geological Survey Professional Paper 1625–A, 

CD-ROM disk 1. 

Stricker, G.D., and Ellis, M.S., 1999d, Coal quality and geochemistry, 

Greater Green River Basin, Wyoming, Chapter GQ in Fort Union 

Coal Assessment Team, 1999 Resource assessment of selected 

Tertiary coal beds and zones in the Northern Rocky Mountains and 

Great Plains Region: U.S. Geological Survey Professional Paper 

1625–A, CD-ROM disk 1. 

U.S. Statutes at Large, 1990, Public Law 101-549, Provisions for attainment and maintenance of National ambient air quality standards: 

101st Congress, 2nd Session, 104, Part 4, p. 2353–3358. 

U.S. Geological Survey, 2000, Federally owned coal and Federal lands 

in the Northern Rocky Mountains and Great Plains Region: U.S. 

Geological Survey Fact Sheet FS-011-00, 6 p. 

Wood, G.H., Jr., Kehn, T.M., Carter, M.D., and Culbertson, W.C., 1983, 

Coal resource classification system of the U.S. Geological Survey: 

U.S. Geological Survey Circular 891, 65 p. 

Manuscript approved for publication December 21, 2001


Published in the Central Region, Denver, Colorado


Graphics by the author


Edited by L.M. Carter