Chapter IN

INTRODUCTION

By R.M. Flores and D.J. Nichols

in U.S. Geological Survey Professional Paper 1625-A
IN-ii

Contents

Perspectives .........................................................................................................IN-1

Objectives ............................................................................................................IN-1

Strategy ................................................................................................................IN-2

Background..........................................................................................................IN-2

Geologic Setting ..................................................................................................IN-3

 Coal geology......................................................................................................IN-3

 Coal stratigraphy................................................................................................IN-4

 Biostratigraphy...................................................................................................IN-5

Depositional Settings and their Influence on Coal Resources.............................IN-6

 Early Paleocene..................................................................................................IN-7

 Middle Paleocene...............................................................................................IN-7

 Late Paleocene ...................................................................................................IN-7

 Influence of Depositional Environments ...........................................................IN-8

Coal Quality.........................................................................................................IN-9

References..........................................................................................................IN-11

Figures

IN-1. Index map of Northern Rocky Mountains and Great Plains region

showing locations of sedimentary basins and distribution of Fort

Union Formation and equivalent strata and coal.

IN-2. Composite stratigraphic section of coal-bearing Paleocene rocks in the

four major basins studied in the Northern Rocky Mountains and Great

Plains region.

IN-3. Fluvial depositional model.
IN-iii

IN-4. Stratigraphic nomenclature for the Paleocene of the Northern Rocky

Mountains and Great Plains region.

IN-5. Ferris coal beds.

IN-6. Wyodak-Anderson coal zone.

IN-7. Beulah-Zap coal zone.

IN-8. Deadman coal zone.

IN-9. Some key species of fossil pollen used in biostratigraphic zonation of

the Paleocene and Eocene in the Rocky Mountain region.

IN-10. Biostratigraphic (palynostratigraphic) zonation of the Paleocene and

adjacent rocks in the Rocky Mountain region.

IN-11. Composite stratigraphic section for the Northern Rocky Mountains

and Great Plains region showing the assessment units with age

relations based on palynostratigraphy.

IN-12. Composite correlation of Paleocene sections based on

palynostratigraphy.

IN-13. Physiographic diagram showing the region in early Paleocene time.

IN-14. Physiographic diagram showing the region in middle Paleocene time.

IN-15. Physiographic diagram showing the region in late Paleocene time.

Tables

IN-1. Arithmetic means of heat-of-combustion (Btu/lb) and moisture, ash,

and total sulfur contents (percent) of coal in the Powder River and

Williston Basins

IN-2. Arithmetic means of pounds of SO2 per million Btu of coal in the

Powder River and Williston Basins

IN-3. Arithmetic means of concentrations of trace elements of

environmental concern in the Powder River and Williston Basins 
IN-1

PERSPECTIVES

The section entitled Perspectives is an Acrobat presentation that summarizes

the rationale for the coal assessment study in the Northern Rocky Mountains

and Great Plains region. The text and illustrations explain the “why,” “how,”

and “where” of the assessment, and demonstrate the benefits to society.

Click here to begin.

OBJECTIVES

The objectives of the coal resource assessment are to:

• Compile the information needed and assess selected coal beds and zones

of the Fort Union Formation and its equivalent formations that are

potentially minable in the next two or three decades.

• Identify clean and compliant coal that meets standards of the U.S.

Environmental Protection Agency for sulfur, ash, and trace elements of

environmental concern.

• Create a publicly available digital database of this coal that can be rapidly

accessed and analyzed to provide information critical to decision-making

by government, industry, and the public.

• Produce widely available digital products accessible in a variety of

interpretive and interactive forms. (Please contact Romeo M. Flores at

rflores@usgs.gov for more information.)
IN-2

STRATEGY

The high quality of coal in selected Fort Union and equivalent coal beds and

zones in the Northern Rocky Mountains and Great Plains region, in general,

and in the Powder River Basin, in particular, makes it an important energy

resource for continued development and expanded utilization within current

and future environmental constraints. Our strategy to investigate and assess

these important coal beds and zones is to create, manage, and analyze digital

databases from which derivative digital products can be generated.

Interpretive and interactive digital presentations and databases are provided

in this report for users to utilize the data and metadata. Thus, this detailed

investigation of these clean and compliant coal resources provides new and

needed information for coal availability and recoverability, and for future

mining development into the next century. The coal data and resource

estimates provided in this report are also needed on a basinwide scale for

potential coal-bed methane resource assessments.

BACKGROUND

• The Fort Union Formation (Paleocene) and equivalent rocks of Paleocene

age in the Northern Rocky Mountains and Great Plains region contain 18

coal beds and zones that yielded more than 38 percent (383 million short

tons) of the greater than 1 billion short tons of coal produced in the

United States in 1998.
IN-3

• Coal in the Fort Union Formation and equivalent rocks is a valuable

resource because the coal beds and zones within these stratigraphic units

are thick, and the coal is clean and compliant (low in ash, low in sulfur,

and relatively low in concentrations of trace elements of environmental

concern named in the Amendments to the 1990 Clean Air Act).

• The coal beds and zones in the Fort Union and equivalent rocks are

targets for continued development and expanded utilization in the next

20-30 years.

• The coal in the Fort Union and equivalent rocks is in demand by as many

as 144 electric power generation plants in 25 States of the conterminous

United States, and also in foreign countries.

• Thus, Fort Union and equivalent coal will make an important

contribution to the economic and industrial growth of the Nation, and its

utilization deserves recognition and assessment.

GEOLOGIC SETTING

COAL GEOLOGY

• The Northern Rocky Mountains and Great Plains region of Wyoming,

Montana, and North Dakota contains a vast expanse of the Fort Union

Formation and equivalent Paleocene coal-bearing rocks (fig. IN-1).

• These coal-bearing rocks (fig. IN-2) exist from the surface down to a

depth of about 6,000 ft in shallow basins, such as the Powder River,
IN-4

Williston, and Greater Great River Basins, and from the surface to a

depth of 12,000 ft in deep basins such as the Hanna Basin.

• The apparent rank of Fort Union and equivalent coal ranges from lignite

to subbituminous in the shallow basins and subbituminous to bituminous

in deep basins.

• Deep basins were influenced more extensively by Tertiary Laramide

deformation than were the shallow basins.

• Paleotectonic history and depositional settings (fig. IN-3) of the swamps

in which this coal accumulated contributed to the high quality of the Fort

Union and equivalent coal.

COAL STRATIGRAPHY

• The Fort Union Formation (fig. IN-4) is present in the Powder River,

Williston, and Greater Green River Basins.

• Stratigraphically equivalent to the Fort Union Formation are coal-bearing

rocks in the Ferris (fig. IN-5) and Hanna Formations in the Hanna and

Carbon Basins of Wyoming.

• Major production of Fort Union coal in the Powder River Basin is from

the Wyodak-Anderson (fig. IN-6), Rosebud, and equivalent coal beds and

zones. These coal deposits, which range from 25 to 140 ft thick, produce

from 25 mines more than 38 percent of the total U.S. coal production.
IN-5

• The producing Fort Union coal beds and zones in the Williston Basin

include the Beulah-Zap (fig. IN-7), Hagel, and Harmon coal beds and

zones. These coal beds and zones range in thickness from 20 to 40 ft.

• Coal production in the Ferris and Hanna Formations in the Hanna Basin

is from the Ferris Nos. 23, 25, 31, 50, and 65 coal beds and Hanna Nos.

77, 78, 79, and 81 coal beds, which are each as much as 36 ft thick.

• The producing Fort Union coal zone in the Greater Green River Basin is

the Deadman coal zone (fig. IN-8), which has beds ranging from 2 to 33

ft thick.

BIOSTRATIGRAPHY

• Biostratigraphy uses fossils to determine age relations and correlations of

coal deposits in the Northern Rocky Mountains and Great Plains region.

• The most common and most useful fossils in coal and coal-bearing rocks

are microscopic spores and pollen grains of ancient plants. Thus,

palynology (the study of plant microfossils) has been applied throughout

the region to provide the biostratigraphic framework.

• Biostratigraphy based on fossil spores and pollen (fig. IN-9) is called

palynostratigraphy.

• In the Northern Rocky Mountains and Great Plains, palynostratigraphic

age determinations of the uplifts, basins, and coal deposits support
IN-6

interpretations of the evolution of the basins and the origin of Fort Union

Formation and equivalent coal resources.

• The regional palynostratigraphic zonation divides the Paleocene into six

biozones designated, from oldest to youngest, P1 through P6 (fig. IN-10).

The biozones are defined by occurrences of species of the related genera

Momipites and Caryapollenites and other species of fossil pollen.

• Palynostratigraphy is used to place all coal beds and zones in the

assessment region in a stratigraphic framework (fig. IN-11).

• Palynostratigraphy is the basis of correlations of coal-bearing rocks

between basins in the Northern Rocky Mountains and Great Plains region

(fig. IN-12).

DEPOSITIONAL SETTINGS AND THEIR INFLUENCE ON

COAL RESOURCES

About 55 to 60 million years ago when the Fort Union and equivalent coalforming peat accumulated, the Northern Rocky Mountains and Great Plains

region was primarily continental (Brown, 1958). Marine and coastal-plain

environments were restricted to areas near the Cannonball Sea in what is

now North Dakota and South Dakota. Areas west and southwest of the

Cannonball Sea, in what is now Montana and Wyoming, were in constant

change as a result of continuing uplift of mountain ranges and formation of

basins between these uplifts. After a few million years had elapsed, river

systems and their associated floodplains, lakes, and swamps formed a

network of waterways and wetlands in the basins.
IN-7

EARLY PALEOCENE

Large river systems (fig. IN-13) in what is now Montana and Wyoming

generally flowed eastward and northeastward toward the Cannonball Sea

(fig. IN-13) in what is now North Dakota and South Dakota (Flores, 1986).

Coal-forming swamps or mires formed between river channels near the

headwaters and downstream parts of river systems. Along the coast of the

Cannonball Sea, delta, barrier, and tidal deposits (fig. IN-13) were formed

(Flores, 1998).

MIDDLE PALEOCENE

Some of the large river systems changed to short, high-gradient streams as

mountain building (fig. IN-14) continued to reshape the landscape. Coalforming mires along river channels and associated lakes were widespread

from the headwaters of the rivers to the coastal plain. The Cannonball Sea

retreated northeastward, followed by an encroaching coastal plain where

mires formed on abandoned delta, barrier, and tidal deposits.

LATE PALEOCENE

As mountain building continued, short, high-gradient drainage systems

within developing basins were either ponded into lake systems (fig. IN-15)

or flowed through the basins toward the seaway. Large coal-forming mires

(fig. IN-15) developed in the basins between river channels and along lake

margins. The extent and distribution of the swamps were controlled partly
IN-8

by the size and pattern of these networks of rivers and lakes, and partly by

mountain-building activity. As a result, coal beds that formed from these

swamps are generally discontinuous and lenticular. Many of the thick peat

accumulations, which resulted in thick coal beds, developed in multiple,

stacked, domed mires (fig. IN-15) that sheltered the peat from floods and

burial by sediments. Coal beds in the Powder River Basin in excess of 200 ft

thick reflect the repeated life cycle of swamp growth, demise, and

rejuvenation over long periods of time within tectonically subsiding basins.

INFLUENCE OF DEPOSITIONAL ENVIRONMENTS

Depositional environments influence the thickness, shape or geometry, and

distribution of Fort Union and equivalent coal. Generally, coal thickness

depends on how long peat is permitted to accumulate within the swamp or

mire. In this region, peat accumulation was primarily influenced by

incursion of river sediments due to floods. Thus, how far the swamp was

from river channels, how low or high was the topography of the mire, and

the chemical and biological conditions existing in the mire determined the

nature and duration of peat accumulation. Thick peat formed in chemically

highly reduced, raised mires removed from river channels, with plant growth

sustained by high rate of rainfall. The shape and distribution of coal beds are

reflected by the location of the peat-forming swamps in the depositional

environments. For example, peat-forming swamps between river channels

formed lenticular shapes. Furthermore, when these river channels are

abandoned, these discontinuous, lenticular, peat-forming swamps advanced

and coalesced over channel deposits, forming a continuous bed.
IN-9

The quality of coal (as demonstrated by sulfur, ash, and trace elements

contents) is directly related to the depositional environment. For example,

peat that accumulated in coastal swamps that were transgressed by brackish

and marine water commonly produces coal that has a high sulfur content.

Peat that accumulates in fluvial or continental areas far removed from

marine influence produces coal that has a low sulfur content. Peat mires that

are protected from sediment-carrying floods by raised topography produce

coal that contains low amounts of ash or fine particulates. However, peat

mires that are topographically low-lying and flooded by sediments produce

coal high in ash and trace-element content.

COAL QUALITY

• Fort Union and equivalent Paleocene coal is considered clean, low

contaminant-bearing, and compliant with the 1990 Clean Air Act

Amendments.

• Coal in the Powder River and Williston Basins contains less sulfur and

ash than coal produced from other regions in the conterminous United

States, as shown in table IN-1 (arithmetic means for the Powder River

Basin based on 279 samples; arithmetic means for the Williston Basin

based on 281 samples).

• When sulfur values are compared on pounds of SO2 per million Btu basis

(table IN-2), Powder River Basin coal has the lowest mean content of

SO2 per million Btu of any coal in the conterminous United States.
IN-10

• The quantity of trace elements of environmental concern named in the

1990 Clean Air Act Amendments (antimony, arsenic, beryllium,

cadmium, chromium, cobalt, lead, manganese, mercury, nickel, selenium,

and uranium) is of increasing importance in meeting compliance

standards.

• Powder River Basin coal has among the lowest concentrations of most of

these elements when compared to coal from other coal-producing regions

in the conterminous United States (table IN-3) on a whole-coal, remnantmoisture basis.
IN-11

REFERENCES

Brown, R.W., 1958, Fort Union Formation in the Powder River Basin,

Wyoming: Wyoming Geological Association Guidebook, 13th

Annual Field Conference, p. 111-113.

Energy Information Administration, 1998, Coal Industry Annual 1997: U.S.

Department of Energy Report DOE/EIA-0584, 256 p.

Flores, R.M., 1986, Styles of coal deposition in Tertiary alluvial deposits,

Powder River Basin, Montana and Wyoming, in Lyons, P.C., and

Rice, C.L., eds., Paleoenvironmental and Tectonic Controls in Coalforming Basins of the United States: Geological Society of America,

Special Paper 210, p. 9-104.

_____1998, Chronostratigraphic distribution and depositional sequences of

producing Paleocene Fort Union coals in the northern Great Plains

[abs.]: Geological Society of America, 1998 Annual Meeting,

Abstracts with Programs, v. 30, no. 7, p. 48.

Nichols, D.J., 1996, Palynological zonation of the Paleocene of Rocky

Mountain intermontane basins [abs.]: Geological Society of America,

1996 Annual Meeting, Abstracts with Programs, v. 28, no. 7, p. 372.

_____1998, Palynostratigraphy of the Fort Union Formation (Paleocene) in

the North Dakota part of the Williston basin and its application to coal

resource assessment [abs.]: Geological Society of America, 1998

Annual Meeting, Abstracts with Programs, v. 30, no. 7, p. 366.
IN-12

Perry, W.J., Flores, R.M., and Nichols, D.J., 1996, The role of sequential

Laramide deformation in the northern Rocky Mountains, Montana,

Wyoming and South Dakota [abs.]: Geological Society of America,

1996 Annual Meeting, Abstracts with Programs, v. 28, no. 7, p. 372.

Resource Data International, Inc., 1996, Outlook for Coal and Competing

Fuels, Number 3, Winter 95/96: Resource Data International, Inc.,

1320 Pearl St., Suite 300, Boulder, Colorado 80302.

_____1998, COALdat-Coal Database: Resource Data International, Inc.,

1320 Pearl St., Suite 300, Boulder, Colorado 80302.

U.S. Bureau of Land Management, 1994, Public Land Statistics: U.S.

Bureau of Land Management, v. 178, 143 p.

U.S. Geological Survey, 1996, Assessing the coal resources of the United

States: U.S. Geological Survey Fact Sheet FS-157-96, 8 p.
1. POWDER RIVER BASIN

2. CARBON BASIN

3. DENVER BASIN

4. GREATER GREEN RIVER BASIN

5. HANNA BASIN

6. NORTH & MIDDLE PARK BASIN

7. BIG HORN BASIN

8. RATON BASIN

9. WILLISTON BASIN

10. WIND RIVER BASIN

Montana

Nebr.

North

Dakota

South

Dakota

Colorado

Wyoming

New Mexico

8

3

6

2

5

10

1

4

7

Surface Fort Union Fm

and equivalent strata

Subsurface Fort Union Fm

and equivalent strata 

Coal mine or lease areas

Coal beds and zones

0 200 Miles

9

Figure IN-1. Index map of Northern Rocky Mountains and Great Plains region showing locations of 

sedimentary basins and distribution of Fort Union Formation and equivalent Paleocene strata and coal.
Wyodak-Anderson

Beulah-Zap 

Hagel 

Harmon

Hansen

Knobloch

Rosebud

Deadman seams 1-5 and A-C

}

}

........................................Powder River Basin

...........................................................Williston Basin

.....................................................................Williston Basin

.....................................................Powder River Basin

...............................................................Williston Basin

............Greater Green River Basin

Hanna Nos. 77-79, 81

Ferris Nos. 23, 

25, 31, 50, & 65 }.......................................................Hanna Basin

................................................Hanna Basin

Johnson-107 .............................................................Carbon Basin

Figure IN-2. Composite stratigraphic section of coal-bearing Tertiary (Paleocene) 

rocks in the four major basins studied in the Northern Rocky Mountains and Great 

Plains region. The named coal beds and zones in the Fort Union Formation and 

equivalent rocks are covered in detail in this assessment. Fort Union Formation and equivalent Paleocene rocks
Braided Streams

Alluvial Fans

Floodplain Lake

Swamp or Mire

Meandering

Stream

Anastomosed 

Stream

Crevasse Splay

Figure IN-3. Fluvial depositional model.

Mountains
Figure IN-4. Stratigraphic nomenclature for the Paleocene of the Northern Rocky 

Mountains and Great Plains region.

Williston

Basin

Powder River

Basin

Greater Green

River Basin

Hanna and

Carbon Basins

Fort Union FormationFort Union Formation

Fort Union

Formation

Tongue River

Member

Lebo

Member

Tullock

Member

Tongue River

Member

Ludlow

Member

Sentinel Butte

Member Hanna

Formation

(part)

Ferris

Formation

(part)

(upper part)

Cannon- (lower part)

ball Mbr.
Figure IN-5. Ferris coal beds.
gure IN-6. Wyodak-Anderson coal zone.
gure IN-7. Beulah-Zap coal zone.
Figure IN-8. Deadman coal zone.
C

G H

A - Momipites wyomingensis, B - Momipites actinus, C - Momipites ventifluminis, 

D - Platycarya platycaryoides, E - Aquilapollenites spinulosus, F - Pistillipollenites mcgregorii, 

G - Insulapollenites rugulatus, H - Caryapollenites veripites

Figure IN-9. Some key species of fossil pollen used in biostratigraphic 

zonation of the Paleocene and Eocene in the Rocky Mountain region.

A B D

E F
Figure IN-10. Biostratigraphic (palynostratigraphic) zonation of the Paleocene 

and adjacent rocks in the Rocky Mountain region.

Biozones are defined by the

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.

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
Wyodak-Anderson

Beulah-Zap 

Hagel 

Figure IN-11. Composite stratigraphic section for the region showing 

the assessment units and age relationships based on palynology.

Harmon

Hansen

Knobloch

Rosebud

Deadman seams

}

}

Powder River Basin

Williston Basin

Williston Basin

Powder River Basin

Williston Basin

Green River Basin

Paleocene

late

(Zones

P5-P6)

middle

(Zones

P3-P4)

early

(Zones

P1-P2)

Hanna Nos. 77-79, 81

Ferris Nos. 23, 

25, 31, 50, & 60 } Hanna Basin

Hanna Basin

Johnson-No. 107 Carbon Basin
Figure IN-12. Composite correlation of Paleocene sections based on 

palynostratigraphy.

500 Meters

Greater

Green River

Basin

Hanna and

Carbon Basins Powder River

Basin

Williston

Basin

Zones: P1 P2 P3

P4 P5 P6
Figure IN-13. Physiographic diagram showing the region in early Paleocene time.

Cannonball 

Sea

MT ND

SD

NE

WY

CO

ID

Mires

Uplifted mountains

Foothills, low plateaus,

or moderate uplands

River drainage

Volcanoes

Sea and lakes

Cordilleran Thrust Belt
Cannonball Sea

MT ND

SD

NE

WY

CO

ID

Mires

Uplifted mountains

Foothills, low plateaus,

or moderate uplands

River drainage

Volcanoes

Sea and lakes

Cordilleran Thrust Belt

Figure IN-14. Physiographic diagram showing the region in middle Paleocene time.
MT ND

SD

NE

WY

CO

ID

Mires

Uplifted mountains

Foothills, low plateaus,

or moderate uplands

River drainage

Volcanoes

Sea and lakes

Cordilleran Thrust Belt

Figure IN-15. Physiographic diagram showing the region in late Paleocene time.
Parameter

Heat-ofcombustion

Moisture

Total sulfur

Ash

Williston

Basin

Appalachian

Basin

Illinois

Basin

Gulf

Coast

Powder

River Basin*

8,220

0.48

6.44

27.66

6,780

1.09

15.12

30.84

6,510

0.84

7.96

37.88

11,600

3.55

10.43

7.86

12,710

2.14

11.58

3.32

* Only the Wyodak-Anderson coal zone is included in the Powder River Basin in this 

 study. All data on an as-received basis.

Table IN-1. Arithmetic means of heat-of-combustion (Btu/lb) and moisture, ash, and total 

sulfur contents (percent) of coal in the Powder River and Williston Basins compared to 

similar analyses from other coal-producing regions in the conterminous United States

Colorado

Plateau

10,020

0.83

13.08

12.21
Parameter

SO2/MMBtu

Williston

Basin

Appalachian

Basin

Illinois

Basin

Gulf

Coast

Powder

River Basin*

1.2 2.5 2.1 5.0 3.4

Table IN-2. Arithmetic means of pounds of SO2 per million Btu (SO2/MMBtu) of coal 

in the Powder River and Williston Basins compared to similar analyses from other coalproducing regions in the conterminous United States

* Only the Wyodak-Anderson coal zone is included in the Powder River Basin in this 

 study. All data on an as-received basis.

Colorado

Plateau

1.5
Parameter

Table IN-3. Arithmetic means of concentrations of trace elements of environmental 

concern in parts per million in coal assessed in the Powder River and Williston Basins 

compared to similar analyses from other coal-producing regions in the conterminous 

United States

Arsenic

Beryllium

Cobalt

Cadmium

Colorado

Plateau

Williston

Basin

Appalachian

Basin

Illinois

Basin

Gulf

Coast

Powder

River Basin*

2.6 3.1

1.9

0.21

0.54

5.1

4.7

0.22

2.3

9.1

2.9

0.08

0.73

2.2

0.11

1.6

10

4.8

2.6

1.5

22

6.7

0.10

2.4

Chromium

Mercury

Nickel

Manganese

6.1 8.0

4.6

26.0

0.13

15

12

130

0.20

7.4

4.3

75.0

0.14

5.9

35

0.095

9.6

15

69

0.11

17

16

25

0.19

Lead

Antimony

Uranium

Selenium

3.0 9.2

1.3

1.1

0.50

8.8

5.0

5.0

0.89

3.5

1.5

0.60

2.0

1.5

0.78

27

2.3

2.0

1.0

8.9

1.8

3.4

1.1

0.74

* Only the Wyodak-Anderson coal zone is included in the Powder River Basin in this 

 study. All data on a whole-coal and remnant-moisture basis.
National Coal Resource Assessment

Perspectives

Northern Rocky Mountains and Great Plains
Why?

How?

Where?

What are benefits to society?

Assessment basins

The USGS is assessing coal in the

Northern Rocky Mountains and Great Plains
 

(1) Utilization of coal 

is rising in the U.S., 

primarily because it 

is the least expensive 

fuel for electrical 

1900 1920 1940 1960 1980 1998 power generation

200

400

600

800

1000

1200

Why? ...three reasons:

MILLIONS OF TONS OF COAL

Source: modified from USGS Fact Sheet FS-157-96
1960 1970 1980 1990 1998

50

0

100

150

200

250

300

350

MILLIONS OF TONS OF COAL

Much of the Nation's coal comes from Wyoming

North Dakota

Montana

Wyoming

Regional Total

About a third of the Nation's coal comes from this assessment region;

more than a fourth comes from the Powder River Basin, Wyoming 

Sources: 

Energy Information

Administration (1998)

and Resource Data

International, Inc. (1998)

400
Where Powder River Basin coal goes

Sales of coal from the Powder River Basin to electric utilities in various 

states, shown as percentages of total production from the basin in 1998

 

Source: Resource Data International, Inc. (1998)

TX

MO

OK

KS

IA

IN

AR

IL

WI

WY

MI

NE

LA

GA

MN

CO

AL

OR

Powder River Basin

4

5

15

12

< 1

FL

2 2

7

6

6

6

< 1

KY

MS

3

3

3

MT

< 1 < 1

< 1

ND

< 1

OH

7

< 1

7

5

3

< 1

AZ
(2) Increased demand for

Powder River Basin coal 

is due to its clean compliant

properties and inexpensive

extraction methods

Why? ... three reasons:
2000

4000

6000

8000

10000

12000

1960 1970 1980 1990 1998

Amount of coal under lease, Powder River Basin, Wyoming

Data from Wyoming State Inspector of Mines 

and U.S. Bureau of Land Management

MILLIONS OF TONS OF COAL
0

50

100

150

200

250

1960 1970 1980 1990 1997

Annual coal production in Powder River Basin, Wyoming

Data from Wyoming State Inspector of Mines

and U.S. Bureau of Land Management

MILLIONS OF TONS OF COAL
(3) The supply of coal 

that is clean, compliant, and

meets socio-economic and

environmental restrictions

is being depleted

Why? ... three reasons:
How much coal will be left in the next century?

Projected annual life of reserves in mining areas in Powder River Basin,

Wyoming, based on a composite of coal and utility company forecasts

planned leasing

no leasing

1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 0

5

10

15

20

25

30

35

RESERVE BASE (YEARS)

Forecast by U.S. Bureau of Land Management (1994)
120

100

80

60

40

20

0

8400-8600

High quality coal is selectively produced

Quantities produced according to thermal quality 

in the Powder River Basin, Wyoming, 1995

MILLIONS OF TONS OF COAL

QUALITY IN BTU'S PER POUND

< 8200 8200-8400 8600-8800 > 8800(limited resource available)

Data from U.S. Bureau of Land Management
Years of life remaining for 19 coal mines in 

the southern Powder River Basin as of 1994

1

4

5

0

Years remaining

Number of mines

< 10 < 15 < 20 < 25 < 30 < 40 < 50 < 60 > 60

Less than

20 years of

resources

20-30

years of

resources

longer-term

resources

4

1 1 1 1

< 35

1

Data from U.S. Bureau of Land Management
(1) Collect data 

and create a modern 

digital coal database 

for public users

How? ... three methods:
(2) Produce various 

digital products such as

maps, text and graphics

presentations, charts, 

and tables

How? ... three methods:
(3) Estimate available 

coal resources and 

identify areas having 

deposits of clean and

compliant coal

How? ... three methods:
Coal exists in 

abundance in lower

Tertiary rocks in the 

assessment region

MT ND

SD

CO

WY

Strippable coal 

Fort Union Formation

and equivalents

Where? ... in the Northern Rocky Mountains and Great Plains
Most clean compliant

Tertiary coal is found

in four basins in the 

assessment region

MT

ND

SD

WY

CO

NM

49o

109o

1 Williston Basin

2 Powder River Basin

3 Hanna and Carbon Basins

4 Greater Green River Basin

 Other basins

45o

41o

37o

105o101o

1

2

3

4

Where? ... in the Northern Rocky

Mountains and Great Plains
Clean compliant coal 

currently is mined in 12

coalfields in four basins in 

the assessment region

1. Gillette

2. Sheridan

3. Decker

5. Colstrip

 Bowman- 6. 

 Dickinson

7. Center-Falkirk

8. Beulah-Zap

 9. Hanna

10. Ferris

12. Point of Rocks-

 Black Butte

MT

ND

SD

WY

CO

NM

49o

 109o

45o

41o

37o

 105o 101o

1

3

2

4

5

6

8

9 10

12

11. South Carbon

4. Ashland

7

11

Where? ... in the Northern Rocky Mountains and Great Plains
(1) Unbiased, publicly available data about 

the Nation's public lands and their energy resources

(2) More knowledgeable management of energy 

resources to strengthen local, State, and 

National economies

Benefits to society:
28%

48.9%

4.2%

5.7%

36.3%

Montana

South Dakota

North Dakota

Colorado

Wyoming

Percent of State acreage

in the assessment region 

that is Federally owned

Data from

U.S. Bureau of Land Management
Montana

North Dakota

South Dakota

Colorado

Wyoming

Data from U.S. Bureau of Land Management

Patented acreage that has coal reserved to the U.S.

1.348

0.187

 Millions of acres of non-Federal 

land in which the U.S. retains 

exclusive rights to coal 

6.659

4.637

2.297
Services

 (includes 

 transportation

 & utilities)

Minerals

 (includes coal)

 

Government 

& Education

Construction

Manufacturing

Agriculture

Sources of income in northeastern Wyoming

26%

43%

6%

5%

2%

18%

Data from U.S. Bureau of Land Management
1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014

$2.50

$3.00

$3.50

$4.00

$4.50

$5.00

$5.50

$6.00

Price of high-Btu coal is expected to increase

Powder River Basin price forecast in 1994 dollars per ton FOB

Source: Resource Data International, Inc. (1996)

8500 Btu

> 8800 Btu

PRICE PER TON OF COAL
0

30

60

90

120

150

180

MILLIONS OF DOLLARS

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Wyoming Federal coal royalty

About half of coal royalty income from Campbell and Converse

Counties (Powder River Basin) was returned to the State of Wyoming

Data from U.S. Minerals Management Service
0

5

10

15

20

25

30

35

40

50

1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Montana Federal coal royalty

Income from Big Horn and Rosebud Counties (Powder River Basin)

MILLIONS OF DOLLARS

Data from U.S. Minerals Management Service