Chapter B

A Summary of the Coal Deposits

in the Colorado Plateau: Arizona,

Colorado, New Mexico, and Utah

By Mark A. Kirschbaum1 and Laura R.H. Biewick1

U.S. Geological Survey Professional Paper 1625–B*

U.S. Department of the Interior

U.S. Geological Survey

National Coal

Resource

Assessment

Click here to return to Disc 1 

Volume Table of Contents

Chapter B of

Geologic Assessment of Coal in the Colorado Plateau:

Arizona, Colorado, New Mexico, and Utah

Edited by M.A. Kirschbaum, L.N.R. Roberts, and L.R.H. Biewick

1

 U.S. Geological Survey, Denver, Colorado 80225

* This report, although in the USGS Professional Paper series,

is available only on CD-ROM and is not available separately
Contents

Introduction .................................................................................................................................................B1

Acknowledgments........................................................................................................................................ 1

Coal-Field Summaries .................................................................................................................................. 3

Arizona................................................................................................................................................... 3

Black Mesa Coal Field ............................................................................................................... 3

Pinedale Coal Field ..................................................................................................................... 6

Colorado ................................................................................................................................................ 8

Book Cliffs Coal Field.................................................................................................................. 8

Carbondale Coal Field .............................................................................................................. 10

Crested Butte Coal Field .......................................................................................................... 12

Danforth Hills Coal Field .......................................................................................................... 14

Durango–Pagosa Springs Coal Field..................................................................................... 16

Grand Hogback Coal Field....................................................................................................... 18

Grand Mesa Coal Field............................................................................................................. 20

Lower White River Coal Field.................................................................................................. 22

Nucla-Naturita Coal Field........................................................................................................ 24

Somerset Coal Field.................................................................................................................. 26

Tongue Mesa Coal Field........................................................................................................... 28

Yampa Coal Field....................................................................................................................... 30

New Mexico ....................................................................................................................................... 33

Barker Creek Coal Field ........................................................................................................... 33

Bisti Coal Field........................................................................................................................... 35

Chaco Canyon Coal Field......................................................................................................... 37

Chacra Mesa Coal Field........................................................................................................... 39

Crownpoint Coal Field .............................................................................................................. 41

Datil Mountains Coal Field ...................................................................................................... 43

Fruitland Coal Field ................................................................................................................... 45

Gallup Coal Field ....................................................................................................................... 47

Hogback Coal Field................................................................................................................... 49

La Ventana Coal Field............................................................................................................... 51

Monero Coal Field..................................................................................................................... 53

Mount Taylor Coal Field ........................................................................................................... 55

Navajo Coal Field ...................................................................................................................... 57

Newcomb-Toadlena Coal Field............................................................................................... 59

Rio Puerco Coal Field ............................................................................................................... 61

Salt Lake Coal Field .................................................................................................................. 63

San Mateo Coal Field ............................................................................................................... 65

Standing Rock Coal Field......................................................................................................... 67

Star Lake Coal Field.................................................................................................................. 69
Tierra Amarilla Coal Field ........................................................................................................ 71

Zuni Coal Field ........................................................................................................................... 73

Utah...................................................................................................................................................... 75

Alton Coal Field ......................................................................................................................... 75

Book Cliffs Coal Field................................................................................................................ 77

Emery Coal Field........................................................................................................................ 79

Henry Mountains Coal Field.................................................................................................... 81

Kaiparowits Plateau ................................................................................................................. 84

Kolob-Harmony Coal Fields..................................................................................................... 86

Salina Canyon Coal Field ......................................................................................................... 88

Sego Coal Field.......................................................................................................................... 90

Tabby Mountain Coal Field ...................................................................................................... 92

Vernal Coal Field ....................................................................................................................... 94

Wales Coal Field........................................................................................................................ 96

Wasatch Plateau Coal Field .................................................................................................... 98

Figure

 1. Map showing location of study area and selected coal fields within Arizona, 

Colorado, New Mexico, and Utah............................................................................................B2
Introduction

This report provides an overview of the geologic setting, distribution, and quality 

of coal deposits of the Colorado Plateau. The Colorado Plateau contains more than 40 

individual coal fi elds within the four-State region of Arizona, Colorado, New Mexico, and 

Utah (fi g. 1). This chapter summarizes data for 47 coal fi elds of the Colorado Plateau 

and provides basic information on the location, general geology, coal resources and 

quality, and what we consider the most useful references for these areas. Each summary 

is essentially an annotated bibliography of the coal fi eld. The coal fi elds can be accessed 

individually by scrolling through the text, by selecting from the bookmarks provided in 

Acrobat Reader 4.0 or higher, or by clicking on the appropriate heading in the chapter 

B table of contents. The summaries can also be accessed from the Colorado Plateau 

ArcView project, which resides on both disc 1 and disc 2 of this 2-CD-ROM set (the 

ArcView project on disc 1 may be queried by means of ArcView Data Publisher; the 

ArcView project on disc 2 provides for full functionality for users who own ArcView 

3.1 or later versions).

Acknowledgments

Digital coverages used in this report were compiled, in part, by Raymond Colley, 

Tracey Mercier, and Jason Stoker, with the help of Bill Larson and Dave Ferderer. Coal 

mine production data was assembled from the Mine Safety and Health Administration 

(MSHA) and Energy Information Administration (EIA) data by Gerald Sullivan. The 

report was reviewed by Vito Nuccio, David Wheeler, Gretchen Hoffman, Rick Scott, Tom 

Judkins, and Bill Keefer. Reviews of selected coal fi elds were by Michael Brownfi eld, 

Robert Hettinger, and Edward Johnson.

A Summary of the Coal Deposits 

in the Colorado Plateau: Arizona, 

Colorado, New Mexico, and Utah

By Mark A. Kirschbaum and Laura R.H. Biewick

B1
B2 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

2. Pinedale

1. Black Mesa

5. Durango-Pagosa Springs 

6. Kolob-

 Harmony

1. Alton 

Utah

5. Kaiparowits 

9. Nucla-Naturita 

4. Henry Mtns 

3. Crested Butte

10. Somerset 

8. Sego 

7. Grand Mesa

12. Wasatch

 Plateau 

11. Wales

7. Salina

 Canyon

2. Carbondale 

1. Book Cliffs

8. Lower White River

2. Book Cliffs 

6. Grand Hogback

3. Emery

4. Danforth Hills

10. Vernal 

9. Tabby Mtn 

11. Yampa 

17. Salt Lake 

6. Datil Mtns

16. Rio Puerco 

21. Zuni 

7. Fruitland

11. Monero

5. Crownpoint 

3. Chacra Mesa

4. Chaco Canyon

19. Standing Rock

10. La Ventana 

2. Bisti

15. Tierra Amarilla 

13. Navajo

14. Newcomb-Toadlena

9. Gallup 

12. Mount Taylor

1. Barker Creek 

8. Hogback

18. San Mateo 

20. Star Lake 

1

1

2 

3 2 

3

4

4

5 5

7

7

6

6

8

8

9

9

5

10

10

11

11

12

Colorado

New Mexico

Arizona

1

1 2

2

3

4

6

5

12

7

8

9

10

11

13

15

14

16

18

20

21

19

17

Coal fields Study area

113

113

106

34 34

40 40

106

0 100 Miles

Figure 1. Map showing location of study area and selected coal fi elds within Arizona, Colorado, New Mexico, and Utah. Different colors are 

used for the coal fi elds to clearly delineate boundaries between the fi elds.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B3

Coal-Field Summaries

Arizona

Black Mesa Coal Field

Location

Black Mesa is located in northeast Arizona within Apache, Coconino, and Navajo 

Counties and is entirely within the Navajo and Hopi Indian Reservations.

Stratigraphy

Early work on the stratigraphy was by Gregory (1917), and the preliminary coal 

geology work was by Campbell and Gregory (1911) and Repenning and Page (1956). 

Biostratigraphic relationships were studied by Peterson and Kirk (1977). The stratigraphic 

nomenclature and thickness of units are from Eaton and others (1987); depositional 

environments are from Eaton and others (1987) and Franczyk (1988).

Table. Stratigraphy—Black Mesa coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Yale Point Sandstone nearshore marine 0-300 

Wepo Formation coastal plain; major coal 300-750 

Rough Rock Sandstone nearshore marine/tidal 0-60 

Toreva Formation nearshore marine; coastal plain, minor coal; fluvial 100-300 

Mancos Shale marine shale 600 

Dakota Sandstone fluvial; nearshore marine; minor coal 45-100 

Coal Deposits

Coal is present in the Dakota, Toreva, and Wepo Formations. Extensive work on 

the coal deposits was completed by Williams (1951) as summarized in Peirce and others 

(1970). Carr (1991) studied the depositional environments of the Wepo coals. Eight coal 

zones are mined from the Wepo and are between 4 and 30 ft thick (Moore, 1977; Fellows, 

1998).

Coal Quality

Most of the coal in all three formations is high-volatile bituminous C, although some 

samples in the Dakota are subbituminous C or, in higher ash samples, lignite (Peirce and 

others, 1970). Proximate/ultimate analyses were compiled by Peirce and others (1970, 

table 1, p. 20: analysis of 11 coals from the Dakota show ash contents between 10.0 and 

30.74 percent, sulfur contents between 0.7 and 2.29 percent, and heating values between 

5,119 and 10,550 Btu/lb; analysis of 7 coals from the Toreva show ash contents between 

8.8 and 19.0 percent, sulfur contents between 0.9 and 1.3 percent, and heating values 

between 9,807 and 11,200 Btu/lb; analysis of 11 coals in the Wepo show an ash content 

between 3.4 and 8.7 percent, sulfur contents between 0.4 and 0.9 percent, and heating 

values of between 10,450 and 12,060 Btu/lb). The table below is compiled from seven 

analyses from Wepo coals collected at the Kayenta and Black Mesa mines (Moore, 1977).
B4 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Original resource estimates for the Dakota, Toreva, and Wepo are 9.6, 6, and 5.65 

billion short tons, respectively (Peirce and others, 1970, p. 27). All estimates are from 

beds greater than 1 ft thick and down to a maximum depth of 1,700 ft of overburden (this 

minimum thickness is assumed from discussion in Peirce and others, 1970, p. 26–34). 

Strippable coal in the Wepo equals about 800 million short tons in areas with less than 

130 ft of overburden (Peirce and others, 1970).

Production History

Ten small underground mines have produced about 300,000 short tons of coal since 

the early 1900’s (Pierce and others, 1970). The Kayenta and Black Mesa surface mines 

have been active since the early 1970’s and produced about 12 million short tons of 

coal in 1995.

References

Campbell, M.R., and Gregory, H.E., 1911, The Black Mesa coal fi eld, Arizona, in Campbell, M.R., ed., 

Contributions to Economic Geology 1909, Part II. Mineral Fuels: U.S. Geological Survey Bulletin 

431, p. 229–238.

Carr, D.A., 1991, Facies and depositional environments of the coal-bearing upper carbonaceous 

member of the Wepo Formation (Upper Cretaceous), northeastern Black Mesa, Arizona, in

Nations, J.D., and Eaton, J.G., eds., Stratigraphy, Depositional Environments, and Sedimentary 

Tectonics of the Western Margin, Cretaceous Western Interior Seaway: Geological Society of 

America Special Paper 260, p. 167–188.

Eaton, J.G., Kirkland, J.I., Gustason, E.R., Nations, J.D., Franczyk, K.J., Ryer, T.A., and Carr, D.A., 1987, 

Stratigraphy, correlation, and tectonic setting of Late Cretaceous rocks in the Kaiparowits and 

Black Mesa basin, in Davis, G.H., and Vanden Dolder, E.M., eds., Geologic Diversity of Arizona and 

its Margins; Excursions to Choice Areas, Geological Society of America 100th Annual Meeting 

Field Trip Guidebook: Arizona Bureau of Geology and Mineral Technology Special Paper 5, p. 

113–125.

Gregory, H.E., 1917, Geology of the Navajo country—A reconnaissance of parts of Arizona, New 

Mexico, and Utah: U.S. Geological Survey Professional Paper 93, 161 p.

Franczyk, K.J., 1988, Stratigraphic revision and depositional environments of the Upper Cretaceous 

Toreva Formation in the northern Black Mesa area, Navajo and Apache Counties, Arizona: U.S. 

Geological Survey Bulletin 1685, 32 p.

Fellows, L.D., 1998, Coal geology of Arizona, in Keystone Coal, p. 573.

Moore, R.T., 1977, Chemical analyses of coal samples from the Black Mesa fi eld, Arizona: The 

Arizona Bureau of Mines Circular 18, 14 p.

Peirce, H.W., Keith, S.B., and Wilt, J.C., 1970, Coal, oil, natural gas, helium, and uranium in Arizona: 

The Arizona Bureau of Mines Bulletin 182, 289 p.

Peterson, F., and Kirk, A.R., 1977, Correlation of Cretaceous rocks in the San Juan, Black Mesa, 

Kaiparowits and Henry Basins, southern Colorado Plateau, in Fassett, J.E., ed., Guidebook of San 

Juan Basin III in northwestern New Mexico: New Mexico Geological Society Guidebook, 28th 

Field Conference, p. 167–178.

Table. Coal in Wepo Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

4.7-9.1 0.3-0.5 9,490-11,560 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B5

Repenning, C.A., and Page, H.G., 1956, Late Cretaceous stratigraphy of Black Mesa, Navajo and Hopi 

Indian Reservations, Arizona: American Association of Petroleum Geologists, v. 40, p. 255–294.

Williams, G.A., 1951, The coal deposits and Cretaceous stratigraphy of the western part of Black 

Mesa: Tucson, University of Arizona, unpub. Ph.D. dissertation, 307 p.
B6 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Pinedale Coal Field

Location

The small Pinedale coal fi eld is located in the southern part of Navajo and Apache 

Counties, Arizona. (Only the Navajo County part of the coal fi eld is shown on fi gure 1).

Stratigraphy

The fi rst and probably only detailed study of the coal was by Veatch (1911). He 

placed the coal within the Cretaceous System. The ages of these rocks were further 

documented by Kirkland (1982), who also provides thickness data.

Table. Stratigraphy—Pinedale coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Tertiary rocks 

Undifferentiated Cretaceous 

 rocks alluvial to marine 200+ 

Triassic rocks 

Coal Deposits

The fi eld contains two coal beds separated by about 15 ft of non-coaly rock. The 

lower bed is generally only 2–3 ft thick, and the upper bed is as much as 12 ft thick but 

contains at least 50 percent non-coal material (Veatch, 1911).

Coal Quality

The rank of the coal is assumed to be subbituminous by Averitt and O’Sullivan 

(1969). The chemistry data is from three analyses by Cooper and others (1947); samples 

are from the Merwin coal prospect.

Table. Coal in undifferentiated Cretaceous rocks. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

16.6-41.1 2.2-3.3 7,100-10,430 

Resources

Averitt and O’Sullivan (1969) made a provisional estimate of 25 million short tons of 

coal in the fi eld based on the data of Veatch (1911).

Production History

The Merwin prospect was opened to obtain coal-thickness and quality information in 

the early 1900’s (Veatch, 1911), and there is no known production from the fi eld.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B7

References

Averitt, Paul, and O’Sullivan, R.B., 1969, Coal, in Mineral and Water Resources of Arizona: Arizona 

Bureau of Mines Bulletin 180, p. 59–69.

Cooper, H.M., Snyder, N.H., Abernethy, R.F., Tarpley, E.C., and Swingle, R.J., 1947, Analyses of mine, 

tipple, and delivered samples: U.S. Bureau of Mines Technical Paper, p. 27–47.

Kirkland, J.I., 1982, Reassessment of the age of the Late Cretaceous section at Mesa Redonda, 

Apache County, Arizona: Journal of Paleontology, v. 56, no. 2, p. 547–550.

Veatch, A.C., 1911, Coal deposits near Pinedale, Navajo County, Arizona, in Campbell, M.R., ed., 

Contributions to Economic Geology 1909: U.S. Geological Survey Bulletin 431, p. 239–242.
B8 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Colorado

Book Cliffs Coal Field

Location

The Book Cliffs coal fi eld is located in Mesa and Garfi eld Counties in western 

Colorado, north of the towns of Fruita and Grand Junction. The coal fi eld is located on 

the southwestern margin of the Piceance Basin. The fi eld is bounded on the west by the 

Utah/Colorado State line, on the east by the Colorado River, and on the south by the 

limit of outcrop.

Stratigraphy

A reconnaissance study of the coal in this fi eld was conducted by Richardson 

(1909). The fi rst detailed mapping of the geology and coal deposits was by Erdmann 

(1934). Other stratigraphic studies of the coal interval have been conducted by Fisher and 

others (1960), Gill and Hail (1975), and Kirschbaum and Hettinger (1998). Thickness 

information is from Fisher and others (1960).

Table. Stratigraphy—Book Cliffs coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Hunter Canyon Formation alluvial plain 375-1,400 

Mount Garfield Formation nearshore marine/coastal plain; major coal 970-1,070 

Sego Sandstone nearshore marine/tidal 0-110 

Mancos Shale marine 3,800 

Coal Deposits

The main coal zones are the Anchor Mine, Palisade, Cameo, and Carbonera of the 

Mount Garfi eld Formation. Presently, the most important beds for mining are in the 

Cameo/Carbonera zone. The Cameo/Carbonera zone is generally poorly exposed due to 

extensive burning of the beds on outcrop. Where the coals are exposed, individual beds 

of the Cameo are as thick as 23 ft (Erdmann, 1934). The coal contains abundant methane 

gas, which has been a problem for the mines in the area since the early 1900’s (Murray 

and others, 1977).

Coal Quality

The table below includes data from the Anchor Mine, Palisade, Carbonera, Cameo, 

and Thomas coal zones in the Mount Garfi eld Formation. The information was compiled 

by Hettinger and others (chap. O, this CD-ROM) based on data in Hornbaker and others 

(1976), Murray and others (1977), Tremain and others (1996), and R.H. Affolter (written 

commun., 1998).

Table. Coal in Mount Garfield Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

4.9-23.3 0.4-1.7 9,833-13,560 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B9

Resources

Landis (1959) estimated about 2.3 billion short tons of bituminous coal as an original 

resource down to a depth of 3,000 ft in an area of 255 mi2. He included all coals greater 

than 14 inches thick in the measured, indicated, and inferred categories. This estimate 

was obtained from Richardson (1907, 1909) and Erdmann (1934), who derived their coalthickness data from outcrops and mines. Hornbaker and others (1976) estimated another 

1.3 billion tons from an additional 145 mi2

 of the fi eld with 3,000 ft of overburden and 

estimated 3.6 billion short tons in areas with 3,000–6,000 ft of overburden for a total of 

7.2 billion short tons of coal for the fi eld.

Production History

Numerous mines have operated in the Book Cliffs coal fi eld since 1888, producing 

from the Anchor Mine, Palisade, Carbonera, and Cameo coal beds (Erdmann, 1934; 

Murray and others, 1977). Currently, only the north portal of the Roadside mine is 

operating in the Book Cliffs fi eld (south portal of the Roadside mine is discussed under 

the Grand Mesa coal fi eld). The north portal has been producing coal since 1994, and 

production averages about 300,000 short tons of coal per year. The coal is transported to a 

unit train loadout on-site and provides coal for its mine-mouth power plant.

References

Erdmann, C.E., 1934, The Book Cliffs coal fi eld in Garfi eld and Mesa Counties, Colorado: U.S. Geological Survey Bulletin 851, 150 p.

Fisher, D.J., Erdmann, C.E., and Reeside, Jr., J.B., 1960, Cretaceous and Tertiary Formations of the 

Book Cliffs, Carbon, Emery, and Grand Counties, Utah, and Garfi eld and Mesa Counties, Colorado: 

U.S. Geological Survey Professional Paper 332, 80 p.

Gill, J.R., and Hail, W.J., Jr., 1975, Stratigraphic sections across Upper Cretaceous Mancos Shale–

Mesaverde Group boundary, eastern Utah and western Colorado: U.S. Geological Survey Oil and 

Gas Investigations Chart OC-68.

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Kirschbaum, M.A., and Hettinger, R.D., 1998, Stratigraphy and depositional environments of the 

late Campanian coal-bearing Neslen/Mount Garfi eld Formations eastern Book Cliffs, Utah and 

Colorado: U.S. Geological Survey Open-File Report 98-43.

Landis, E.R., 1959, Coal resources of Colorado: U.S. Geological Survey Bulletin 1072-C, p. 131–232.

Murray, D.K., Fender, H.B., and Jones, D.C., 1977, Coal and methane gas in the southeastern part of 

the Piceance Creek Basin, Colorado, in Veal, H.K., ed., Exploration Frontiers of the Central and 

Southern Rockies, Rocky Mountain Association of Geologists, 1977 Symposium, p. 379–405.

Richardson, G.B., 1907, The Book Cliffs coal fi eld, between Grand River, Colorado, and Sunnyside, 

Utah: U.S. Geological Survey Bulletin 316, 63 p.

Richardson, G.B., 1909, Reconnaissance of the Book Cliffs coal fi eld: U.S. Geological Survey Bulletin 

371, 54 p.

Tremain, CM., Hornbaker, A.L., Holt, R.D., and Ladwig, L.R., 1996, 1995 summary of coal resources 

in Colorado: Colorado Geological Survey Department of Natural Resources Special Publication 

41, 19 p.
B10 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Carbondale Coal Field

Location

The fi eld is located on the eastern side of the Piceance Basin within Garfi eld, Gunnison, and Pitkin Counties. The fi eld stretches from Redstone, Colo., northward for about 

25 mi to near the town of Carbondale. The Coal Basin area in the south part of the fi eld is 

an eroded anticline formed by the intrusion of a small laccolith (Collins, 1977).

Stratigraphy

The coal-bearing rocks are within the Iles and Williams Fork Formations of the 

Mesaverde Group. Thickness of the units is from Collins (1977), measured in the Coal 

Basin area.

Table. Stratigraphy—Carbondale coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Williams Fork Formation 

 undifferentiated alluvial plain 2,350 

 Paonia Shale Member alluvial plain; major coal 500 

 Bowie Shale Member marine-coastal plain; major coal 475-605 

Iles Formation 

 Rollins Sandstone 

 Member nearshore marine 84-145 

 Tongue of Mancos 

 Shale marine 800-1,000 

 Cozzette Sandstone 

 Member nearshore marine 40-45 

Mancos Shale marine 4,000+ 

Coal Deposits

The coals are present in three zones in the Williams Fork Formation, all located 

above major nearshore marine sandstones and each of which are separated by 100–200 

ft of section (Collins, 1977). In ascending order, the coal zones are the Wheeler, South 

Canyon, and Coal Ridge, and individual coal beds within the zones are as much as 25 ft 

thick (Hettinger and others, chap. O, this CD-ROM).

Coal Quality

In the northern part of the fi eld, the coals are high-volatile B bituminous and noncoking, whereas in the southern part of the fi eld, the coals are metamorphosed by igneous 

intrusions to high-volatile A bituminous, medium-volatile bituminous, and locally to 

semianthracite and anthracite and strongly coking (Hornbaker and others, 1976). The coal 

contains high methane levels, ranging from 1,000–4000 cubic ft gas per ton (Murray and 

others, 1977). The following table is from Hettinger and others (chap. O, this CD-ROM), 

summarizing data from Hornbaker and others (1976) and Murray and others (1977).
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B11

Resources

Original in-place resources for coal with as much as 6,000 ft of overburden were 

estimated to be 5.2 billion short tons for the fi eld (Hornbaker and others, 1976). 

Production History

At least 13 major coal mines have operated in the Carbondale fi eld from 1888 to 

1990 (Murray and others, 1977).

References

Collins, B.A., 1977, Geology of the Coal Basin area, Pitkin County, Colorado, in Veal, H.K., ed., Exploration Frontiers of the Central and Southern Rockies: Rocky Mountain Association of Geologists, 

1977 Symposium, p. 363–377.

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Murray, D.K., Fender, H.B., and Jones, D.C., 1977, Coal and methane gas in the southeastern part of 

the Piceance Creek Basin, Colorado, in Veal, H.K., ed., Exploration Frontiers of the Central and 

Southern Rockies, Rocky Mountain Association of Geologists, 1977 Symposium, p. 379–405.

Table. Coal in Williams Fork Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

1.9-16.2 0.3-2.1 10,160-15,190 
B12 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Crested Butte Coal Field

Location

This coal fi eld is located at the southeastern edge of the Piceance Basin in Gunnison 

County, Colorado. The fi eld, which comprises the Ohio Creek and Crested Butte coal 

districts, lies east of Grand Mesa and the West Elk Mountains along the Ohio Creek and 

Slate River valleys.

Stratigraphy

The coal-bearing unit is the Mesaverde Formation. The area and the coals have 

been structurally disrupted by numerous igneous intrusions, which have caused extensive 

folding and faulting (Lee, 1912; Gaskill and others, 1986).

Table. Stratigraphy—Crested Butte coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mesaverde Formation nearshore marine; coastal plain; major coal 1600-1700 

Mancos Shale marine 3,600 

Coal Deposits

The coals are poorly exposed on outcrops that are between about 9,000 and 11,500 ft 

above sea level (Lee, 1912). There are as many as four major coal beds as thick as 25 ft 

and numerous thin beds (Gaskill and others, 1986). Beds are named 1, 2 (Kubler), 3, 4, 5, 

and 6 in the Crested Butte district and A–B in the Ohio Creek district.

Coal Quality

The coal is reported as high volatile bituminous C through anthracite and is of 

coking quality (Gaskill and others, 1986). The following table is from Hettinger and 

others (chap. O, this CD-ROM) summarizing data from Hornbaker and others (1976) and 

Murray and others (1977).

Table. Coal in Mesaverde Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

3.2-9.1 0.4-1.9 11,080-14,440 

Resources

Hornbaker and others (1976) reported about 1.5 billion short tons of coal from beds 

with less than 6,000 ft of overburden in an area of about 240 mi2.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B13

Production History

Historically, 11 major mines and numerous smaller mines operated in the Crested 

Butte coal fi eld from 1881 into the late 1970’s (Gaskill and others, 1986; Murray and 

others, 1977). Most of the coal produced from the area was of coking grade. Cumulative 

production from the Crested Butte #1 and #2 mines was more than 10 million short tons 

of coking coal from 1883 until 1952. Most was mined from the number 2 (Kubler) and 

number 3 beds (Hornbaker and others, 1976).

References

Lee, W.T., 1912, Coal fi elds of Grand Mesa and the West Elk Mountains, Colorado: U.S. Geological 

Survey Bulletin 510, 237 p.

Gaskill, D.L., Colman, S.M., DeLong, J.E., Jr., and Robinson, C.H., 1986, Geologic map of the Crested 

Butte quadrangle, Gunnison County, Colorado: U.S. Geological Survey Geologic Quadrangle Map 

GQ-1580, scale 1:24,000.

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Murray, D.K., Fender, H.B., and Jones, D.C., 1977, Coal and methane gas in the southeastern part of 

the Piceance Creek Basin, Colorado, in Veal, H.K., ed., Exploration Frontiers of the Central and 

Southern Rockies: Rocky Mountain Association of Geologists, 1977 Symposium, p. 379–405.
B14 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Danforth Hills Coal Field

Location

The Danforth Hills coal fi eld is located within Rio Blanco and Moffat Counties in 

northwestern Colorado.

Stratigraphy

The fi rst major mapping of the geology with detailed descriptions of the coal was 

by Gale (1910). More detailed mapping and measurements of the coal deposits were 

completed by Hancock (1925) and by Hancock and Eby (1930). Thicknesses of units are 

from Hancock and Eby (1930).

Table. Stratigraphy—Danforth Hills coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mesaverde Group nearshore marine; coastal plain 

 Williams Fork 

 Formation 

major coal 4,500-5,000 

 Iles Formation minor coal 1,350-1,600 

Mancos Shale marine 5,000 

Coal Deposits

The Black Diamond coal group of the Iles Formation contains coal as thick as 14 ft 

(Hancock and Eby, 1930). The Williams Fork contains three major coal zones (groups). 

In ascending order, these are the Fairfi eld coal group (as thick as 29 ft with a parting), 

and the Goff and Lion Canyon coal groups (each generally less than 10 ft thick, but as 

thick as 18 ft) (Hancock and Eby, 1930). The Fairfi eld is the most important coal group 

and contains seven coal zones. The Fairfi eld coal group contains at least 26 coal beds 

greater than 5 ft thick; 20 of these coal beds have a maximum thickness greater than 12 ft 

(Brownfi eld and others, chap. M, this CD-ROM).

Coal Quality

The coals are mainly high-volatile B and C bituminous; average ash contents are 

3.7–10.0 percent in the Iles and 2.2–9.6 percent in the Williams Fork; average sulfur 

contents are 0.4–0.6 percent in the Iles and 0.3–1.4 percent in the Williams Fork (Murray, 

1981). Brownfi eld and others (chap. M, this CD-ROM) contains a detailed discussion of 

the quality of the Fairfi eld coal group coals.

Resources

Hancock and Eby (1930) reported an estimated original coal resource on a coalgroup basis of 10.6 billion short tons in areas with less than 3,000 ft of overburden 

for the Meeker quadrangle. Landis (1959) reported an estimated original coal resource 

on an individual-bed basis of 7.9 billion short tons in areas under less than 3,000 ft of 

overburden for the Danforth Hills coal fi eld. Hornbaker and others (1976) reported an 

estimated original coal resource of 10.5 billion short tons in areas under less than 6,000 ft 

of overburden for the Danforth Hills coal fi eld.

The Fairfi eld coal group of the Williams Fork Formation (Hancock and Eby, 1930) 

contains many potentially economic coal beds in the Danforth Hills coal fi eld and was the 

only unit newly assessed during the present study (see Brownfi eld and others, chap. M, 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B15

this CD-ROM). The Fairfi eld coal group contains an estimated original coal resource of 

about 21 billion short tons in the identifi ed and hypothetical resource categories.

Production History

Coal is currently mined by surface methods in the Danforth Hills coal fi eld at the 

Colowyo mine, operated by Kennecott Corporation. Coal production averaged about 4.5 

million short tons per year from 1991 to 1995 from the upper part of the Fairfi eld coal 

group (G. Sullivan, written commun., 1997—compiled from Mine Safety and Health 

Administration data).

References

Gale, H.S., 1910, Coal fi elds of northwestern Colorado and northeastern Utah: U.S. Geological Survey 

Bulletin 415, 265 p.

Hancock, E.T., 1925, Geology and coal resources of the Axial and Monument Butte quadrangles, 

Moffat County, Colorado: U.S. Geological Survey Bulletin 757, 134 p.

Hancock, E.T., and Eby, J.B., 1930, Geology and coal resources of the Meeker quadrangle, Moffat 

and Rio Blanco Counties, Colorado: U.S. Geological Survey Bulletin 812-C, p.191–242.

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Landis, E.R., 1959, Coal resources of Colorado: U.S. Geological Survey Bulletin 1072-C, p. 131–232.

Murray, D.K., 1981, Upper Cretaceous (Campanian) coal resources of western Colorado, in Epis, R.C. 

and Callender, J.F., eds., Western Slope Colorado: New Mexico Geological Society Guidebook, 

32nd Field conference, p. 233–239.
B16 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Durango–Pagosa Springs Coal Field

Location

The fi eld is located in Archuleta, La Plata, and Montezuma Counties in southwestern 

Colorado. The fi eld is located on the northern edge of the San Juan Basin (Murray, 1980). 

Part of the fi eld is within the Southern Ute Indian Reservation (Sandberg, 1990).

Stratigraphy

The geology of the coal deposits was mapped in detail in three separate studies: Zapp 

(1949) completed the western part of the area (Durango fi eld), Barnes (1953) completed 

the central part of the area (Los Pinos River fi eld), and Wood and others (1948) completed 

the geology of the eastern part of the area. Thicknesses of units are from Zapp (1949) and 

Wood and others (1948); the coal-bearing Fruitland and Menefee Formations thin toward 

the eastern part of the area.

Table. Stratigraphy—Durango-Pagosa Springs coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Fruitland Formation coastal plain; major coal 0-310 

Pictured Cliffs Sandstone nearshore marine 0-220 

Lewis Shale marine 1,830-2,400 

Cliff House Sandstone nearshore marine maximum 320 

Menefee Formation coastal plain; major coal maximum 200 

Point Lookout Sandstone nearshore marine maximum 400 

Mancos Shale marine 1,890-2,370 

Dakota Sandstone alluvial/coastal plain; minor coal 160-270 

Coal Deposits

Coal is present in the Dakota Sandstone and the Menefee and Fruitland Formations. 

In the Dakota, an individual coal bed reaches a maximum thickness of 8 ft (Shomaker and 

Holt, 1973). In the Menefee, there are as many as nine coal zones (Tremain and others, 

1996) that are as thick as 9 ft (Zapp, 1949). In the Fruitland, there are numerous beds, 

and the maximum composite thickness is thought to be as much as 40 ft of coal in an 

80-ft-thick zone (Zapp, 1949).

Coal Quality

The Menefee coals are high volatile A and B bituminous and the Fruitland coals are 

high volatile B and C bituminous (Murray, 1980). The ash, sulfur, and heating contents in 

the following tables are from (Murray, 1981).

Table. Coal in Fruitland Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

19.5-26.6 0.7-0.8 11,230-12,140 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B17

Resources

For the Ute Mountain Ute and Southern Ute Indian Reservations (both Tribal and 

non-Tribal ownership), Shomaker and Holt (1973) estimated total coal resources in all 

overburden categories: 12 billion short tons of coal in the Dakota Sandstone; 16 billion 

short tons in the Menefee; and 35 billion short tons in the Fruitland. Sandberg (1990) 

estimated 16 billion short tons for the Fruitland in the Southern Ute Reservation alone. 

Within the rest of the Durango fi eld north of the reservations, Zapp (1949) estimated 

13 billion short tons in the Menefee, of which about 3 billion short tons are in beds 

greater than 14 inches thick and under less than 3,000 ft of overburden. No reliable 

estimates were found for the eastern part of the area near Pagosa Springs, but the coals 

are generally thinner and the dips of strata are steeper than in the western part of the 

area (Shomaker, 1971).

Production History

As of 1981, 9.5 million short tons of coal have been produced from the combined 

area (called San Juan River region in some reports) from about 200 mines (Murray, 

1981).

References

Barnes, H., 1953, Geology of the Ignacio area, Ignacio and Pagosa Springs quadrangles, La Plata and 

Archuleta Counties, Colorado: U.S. Geological Survey Oil and Gas Investigations Map OM-138.

Murray, D.K., 1980, Coal in Colorado, in Kent, H.C., and Porter, K.W., eds., Colorado Geology: Rocky 

Mountain Association of Geologists, p. 205–216.

Murray, D.K., 1981, Upper Cretaceous (Campanian) coal resources of western Colorado in Epis, R.C. 

and Callender, J.F., eds., Western Slope Colorado: New Mexico Geological Society Guidebook, 

32nd Field conference, p. 233–239.

Sandberg, D.T., 1990, Coal resources of Upper Cretaceous Fruitland Formation in the Southern Ute 

Indian Reservation, southwestern Colorado, in Zech, R.S., ed., Geology and Mineral Resources of 

the Southern Ute Indian Reservation: U.S. Geological Survey Professional Paper 1505-D, 24 p.

Shomaker, J.W., 1971, Pagosa Springs Cretaceous area, in Shomaker, J.W., Beaumont, E.C., and 

Kottlowski, F.E., eds., Strippable low-sulfur coal resources of the San Juan Basin in New Mexico 

and Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 99–102.

Shomaker, J.W., and Holt, R.D., 1973, Coal resources of Southern Ute and Ute Mountain Ute Indian 

Reservations, Colorado and New Mexico: New Mexico State Bureau of Mines and Mineral 

Resources Circular 134, 22 p.

Tremain, C.M., Hornbaker, A.L., Holt, R.D., and Ladwig, L.R., 1996, 1995 summary of coal resources 

in Colorado: Colorado Geological Survey Department of Natural Resources Special Publication 

41, 19 p.

Wood, G.H., Kelley, V.C., and MacAlpin, A.J., 1948, Geology of southern part of Archuleta County, 

Colorado: U.S. Geological Survey Oil and Gas Investigations Preliminary Map 81.

Zapp, A.D., 1949, Geology and coal resources of the Durango area, La Plata and Montezuma Counties, Colorado: U.S. Geological Survey Oil and Gas Investigations Preliminary Map 109.

Table. Coal in Menefee Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

3.4-16.6 0.6-1.3 10,860-14,700 
B18 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Grand Hogback Coal Field

Location

The Grand Hogback coal fi eld is located on the east side of the Piceance Basin in 

Garfi eld and Rio Blanco County, Colorado. The fi eld extends along the Grand Hogback 

monocline from Meeker to Glenwood Springs, Colo. The monocline dips steeply to the 

west, ranging from about 40° to almost vertical.

Stratigraphy

The best synopsis of the stratigraphy and coal geology of the area is by Collins 

(1976).

Table. Stratigraphy—Grand Hogback coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Williams Fork Formation nearshore marine/coastal plain: major coal 3,600-5,155 

Iles Formation nearshore marine/coastal plain: minor coal 915-1,060 

Coal Deposits

Most of the coal mined from the area came from the Fairfi eld (Middle) coal group 

of the Williams Fork Formation. As many as nine individual coal beds are present within 

a stratigraphic interval of about 470 ft (Collins, 1976, p. 26, Rifl e Gap section). Beds are 

identifi ed, in ascending order: A, B, C, D, Allen, Anderson, Wheeler, E, and F (Hornbaker 

and others, 1976). The Wheeler coal bed is the thickest (as thick as 50 ft) near New 

Castle, Colo. (Collins, 1976). Coal is also present in the South Canyon coal group in the 

upper part of the Williams Fork Formation.

Coal Quality

The following table is from a compilation by Hettinger and others (chap. O, this 

CD-ROM) summarizing data from Hornbaker and others (1976), Murray and others 

(1977), and Tremain and others (1996).

Table. Coal in Williams Fork Formation. 

[Values reported on an as-received basis]

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

3.1-11.3 0.3-0.9 11,020-13,270 

Resources

Total original resources to a depth of 6,000 ft of overburden were estimated by 

Hornbaker and others (1976) at 3.1 billion short tons.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B19

Production History

At least nine major mines operated in the area from 1888 to 1968, producing mainly 

from the Wheeler and Allen coal beds (Murray and others, 1977). In the 1990’s, only 

the Eastside mine was operating in the coal fi eld. As of 1994, the Eastside produced less 

than 4,000 short tons of coal.

References

Collins, B.A., 1976, Coal deposits of the Carbondale, Grand Hogback, and southern Danforth Hills 

coal fi elds, eastern Piceance Basin, Colorado: Quarterly of the Colorado School of Mines, v. 71, 

no. 1, 138 p.

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Murray, D.K., Fender, H.B., and Jones, D.C., 1977, Coal and methane gas in the southeastern part of 

the Piceance Creek Basin, Colorado, in Veal, H.K., ed., Exploration Frontiers of the Central and 

Southern Rockies: Rocky Mountain Association of Geologists, 1977 Symposium, p. 379–405.

Tremain, CM., Hornbaker, A.L., Holt, R.D., and Ladwig, L.R., 1996, 1995 summary of coal resources 

in Colorado: Colorado Geological Survey Department of Natural Resources Special Publication 

41, 19 p.
B20 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Grand Mesa Coal Field

Location

The Grand Mesa coal fi eld extends from the Colorado River to Leroux Creek, 

located near the town of Cedaredge within Mesa and Delta Counties, Colorado. Numerous mines produced coal in the area just northwest of Cedaredge since the 1920’s (Murray 

and others, 1977).

Stratigraphy

The stratigraphy of the fi eld was fi rst studied in detail by Lee (1912). Few studies 

have followed, probably because of the generally poor exposures of the coal. Approximate 

thicknesses of units in the following table are from Lee (1912).

Table. Stratigraphy—Grand Mesa coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mesaverde Formation 

 undifferentiated alluvial plain 1,500 

 Paonia Shale Member coastal plain 400 

 Bowie Shale Member coastal plain; major coal 400 

 Rollins Sandstone 

 Member nearshore marine 100 

Mancos Shale marine 3,000+ 

Coal Deposits

Coal is present in a zone within about 200 ft above the Rollins Sandstone Member 

of the Mesaverde Formation. The coals are named A through F in ascending order, and 

generally only a couple of the seams are of minable thickness at any one place (Hornbaker 

and others, 1976).

Coal Quality

The table below includes data from the Palisade and Cameo coal zones in the Mount 

Garfi eld Formation. The information was compiled by Hettinger and others (chap. O, this 

CD-ROM) and is based on data collected from Hornbaker and others (1976), Murray and 

others (1977), Tremain and others (1996), and R.H. Affolter (written commun., 1998).

Table. Coal in Mount Garfield Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

2.1-23.3 0.4-2.2 8,300-13,490 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B21

Resources

Hornbaker and others (1976) estimated about 8.6 billion short tons of coal resource 

in beds greater than 5 ft thick and having as much as 6,000 ft of overburden.

Production History

Presently, only the south portal of the Roadside mine, in the extreme northwestern 

part of the fi eld, produces coal. Ten major mines operated from 1914 to 1972 around the 

town of Cedaredge, Colo. (Murray and others, 1977).

References

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Lee, W.T., 1912, Coal fi elds of Grand Mesa and the West Elk Mountains, Colorado: U.S. Geological 

Survey Bulletin 510, 237 p.

Murray, D.K., Fender, H.B., and Jones, D.C., 1977, Coal and methane gas in the southeastern part of 

the Piceance Creek Basin, Colorado, in Veal, H.K., ed., Exploration Frontiers of the Central and 

Southern Rockies: Rocky Mountain Association of Geologists, 1977 Symposium, p. 379–405.

Tremain, CM., Hornbaker, A.L., Holt, R.D., and Ladwig, L.R., 1996, 1995 summary of coal resources 

in Colorado: Colorado Geological Survey Department of Natural Resources Special Publication 

41, 19 p.
B22 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Lower White River Coal Field

Location

The coal fi eld is located in Moffat and Rio Blanco Counties and in a small portion 

of Garfi eld County in northwestern Colorado. The fi eld is part of two basins: the 

northwestern margin of the Piceance Basin and the northeastern margin of the Uinta 

Basin.

Stratigraphy

The coal geology of the area was fi rst studied in detail by Gale (1910). Subsequent 

detailed mapping of the coal at a scale of 1:24,000 was conducted in the late 1960’s to 

early 1980’s (e.g., Barnum and Garrigues, 1980) and part of the fi eld (Deserado area) is 

summarized in Brownfi eld and others (chap. N, this CD-ROM). The following average 

thicknesses of units are from Barnum and Garrigues (1980).

Table. Stratigraphy—Lower White River coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mesaverde Group 

 upper unit alluvial plain 1,750 

 coal unit coastal plain; major coal 100-180 

 lower unit coastal plain 200 

Coal Deposits

The coal unit of the Mesaverde Group contains as many as nine coal zones, named in 

ascending order as the A, B, upper B, D, E, F, G, H, and I beds. The two main zones in the 

Deserado mine area are the B and D—in this area the coals have a combined thickness as 

much as 14 ft in two benches (Brownfi eld and others, chap. N, this CD-ROM).

Coal Quality

The coals are high-volatile bituminous C in rank; ash contents range from 4.4 to 8.5 

percent and sulfur contents range from 0.4 to 0.5 percent (Hornbaker and others, 1976). 

Information in the following table is from Brownfi eld and others (chap. N, this CD-ROM) 

and is based on 13 analyses.

Table. Coal in Mesaverde Group. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

4.1-23.9 0.4-1.1 7,240-11,720 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B23

Resources

About 7 billion short tons of coal was estimated to be originally present in about 550 

mi2 of the fi eld in areas where the coal is under less than 1,000 ft of overburden (Landis, 

1959). The two main zones in the Deserado area contain about 440 million short tons of 

identifi ed coal resources in beds greater than 1.2 ft thick in areas where the maximum 

overburden is about 1,500 ft (Brownfi eld and others, chap. N, this CD-ROM).

Production History

There is one active mine in the area, the Deserado mine, a longwall operation that 

has produced an average of about 1.3 million short tons of coal per year between 1991 

and 1995 (G. Sullivan, written commun., 1997—compiled from Mine Safety and Health 

Administration data).

References

Barnum, B.E., and Garrigues, R.S., 1980, Geologic map and coal sections of the Cactus Reservoir 

quadrangle, Rio Blanco and Moffat Counties, Colorado: U.S. Geological Survey Miscellaneous 

Field Studies Map MF-1179, 1:24,000 scale.

Gale, H.S., 1910, Coal fi elds of northwestern Colorado and northeastern Utah: U.S. Geological Survey 

Bulletin 415, 265 p.

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Landis, E.R., 1959, Coal resources of Colorado: U.S. Geological Survey Bulletin 1072-C, p. 131–232.
B24 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Nucla-Naturita Coal Field

Location

This is a small coal fi eld located in Montrose County in western Colorado. The 

coal-bearing formation also extends into Dolores, Mesa, Montezuma, Ouray, and San 

Miguel Counties in western Colorado (Jones and others, 1978; Eakins, 1986), but these 

coals are presently of little importance for exploitation because they are generally thin 

and discontinuous.

Stratigraphy

Coal is present in the Dakota Sandstone. Thickness of units is from Tremain and 

others (1996).

Table. Stratigraphy—Nucla-Naturita coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mancos Shale marine not recorded 

Dakota Sandstone coastal plain; minor coal 330 

Burro Canyon Formation alluvial plain not recorded 

Coal Deposits

In Montrose County, three minable coal beds 3–5 ft thick are present. In ascending 

order, they are the Drott, Oberding, and No. 3 coal zones (Murray, 1980). Haines (1978) 

describes a lower zone (No. 3) and an upper zone (No. 2); the lower zone is composed of 

two thin beds less than 2 ft thick each and the upper zone is as much as 6.3 ft thick.

Coal Quality

The following table of coal quality data is from Murray (1981).

Table. Coal in Dakota Sandstone. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

6.1-12.8 0.5-1.1 10,010-13,380 

Resources

In the main part of the fi eld, near the only presently active mine, a 15-mi2 area was 

estimated to have an original resource of about 114 million short tons of coal (Landis, 

1959).

Production History

One surface mine is active in the fi eld, and produced 361,500 short tons of coal in 

1996 (Resource Data International, 1998). All of the coal is provided to the nearby Nucla 

power plant located near the mine (Murray, 1981).
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B25

References

Eakins, W., 1986, Coal resources of the Dakota Sandstone, southwestern Colorado: Colorado Geological Survey Open-File Report 86-1A, 77 p.

Haines, D.V., 1978, Core-hole drilling and coal analysis report for nine holes drilled during 1977 in 

the Nucla coal fi eld, Montrose County, Colorado: U.S. Geological Survey Open-File Report 78-899, 

37 p.

Jones, D.C., Schultz, J.E., and Murray, D.K., 1978, Coal resources and development map of Colorado: 

Colorado Geological Survey Map Series 9, scale 1:500,000.

Landis, E.R., 1959, Coal resources in Colorado: U.S. Geological Survey Bulletin 1072-C, p. 131–232.

Murray, D.K., 1980, Coal in Colorado, in Kent, H.C., and Porter, K.W., eds., Colorado Geology: Rocky 

Mountain Association of Geologists, p. 205–216.

Murray, D.K., 1981, Upper Cretaceous (Campanian) coal resources of western Colorado, in Epis, R.C. 

and Callender, J.F., eds., Western Slope Colorado: New Mexico Geological Society Guidebook, 

32nd Field conference, p. 233–239.

Resource Data International, Inc., 1998, COALdat database: Boulder, Colo., Resource Data International, Inc.

Tremain, CM., Hornbaker, A.L., Holt, R.D., and Ladwig, L.R., 1996, 1995 summary of coal resources 

in Colorado: Colorado Geological Survey Department of Natural Resources Special Publication 

41, 19 p.
B26 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Somerset Coal Field

Location

The Somerset coal fi eld is located in Delta (Paonia area) and Gunnison (Somerset 

area) Counties in west-central Colorado, and lies in the valley of the North Fork of the 

Gunnison River and its tributaries.

Stratigraphy

The fi rst comprehensive study of the stratigraphy and coal geology of the coal fi eld 

was by Lee (1912). Thicknesses given below are from Dunrud (1989a, 1989b).

Table. Stratigraphy—Somerset coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mesaverde Formation 

 Ohio Creek Member alluvial plain 500-900 

 Barren member alluvial plain 750-1,000 

 Paonia Shale and 

 Bowie Shale 

 Mbrs undivided coastal plain; major coal 250-650 

 Rollins Sandstone 

 Member nearshore marine 80-200 

Mancos Shale marine 4,000-4,500 

Coal Deposits

Coals from the Bowie Shale Member of the Mesaverde Formation are mined from 

beds whose individual thicknesses range between 8.5 and 18 ft; mined beds from the 

Paonia Shale Member of the Mesaverde Formation range in thickness from 12 to 13 

ft (Hornbaker and others, 1976). Individual coal beds reach a maximum thickness of 

between 25 and 30 ft (Murray, 1980). A major longwall operation, the West Elk mine, is 

producing coal from the B seam and taking 12 ft out of a 23-ft bed (Fiscor, 1998). The 

main beds are named the A (Old King), B (Somerset), C (Bear), D (Oliver), and E, with 

historical production coming from all beds.

Coal Quality

The coals in the Somerset area are of good coking quality and are reported to be of 

marginal to premium high-volatile A and B bituminous (Goolsby and others, 1979). The 

table below includes data from the Coal Ridge, South Canyon, and Cameo-Wheeler coal 

zones of the Mesaverde Formation and was compiled by Hettinger and others (chap. O, 

this CD-ROM) based on data collected from Toenges and others (1949, 1952), Hornbaker 

and others (1976), Murray and others (1977), Tremain and others (1996), and R.H. 

Affolter (written commun., 1998).
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B27

Resources

About 8 billion short tons of coal are estimated for this fi eld down to a depth of 6,000 

ft (Hornbaker and others, 1976).

Production History

Historically, nine major mines operated between 1902 and 1974 in the Somerset 

coal fi eld (Murray and others, 1977). Five mines (Bear, Hawks Nest, #2 and #3, Orchard 

Valley, and Somerset) were active as of 1977 (Murray, 1977). As of 1995, there were three 

active mines in the area (Bowie mine #1, Sanborn Creek, and West Elk), and together 

these mines produced about 6.5 million short tons of coal that year. The West Elk mine is 

a longwall operation in the B seam with a 12-ft high cut and a 950-ft-wide panel. It is one 

of fi ve underground mines in the United States that produced more than 5 million short 

tons of coal in 1997 (Fiscor, 1998).

References

Dunrud, C.R., 1989a, Geologic map and coal stratigraphic framework of the Cedaredge area, Delta 

County, Colorado: U.S. Geological Survey Coal Investigations Map C-116, 1:50,000 scale.

Dunrud, C.R., 1989b, Geologic map and coal stratigraphic framework of the Paonia area, Delta and 

Gunnison Counties, Colorado: U.S. Geological Survey Coal Investigations Map C-115, 1:50,000 

scale.

Fiscor, S., 1998, U.S. longwalls thrive: Coal Age, February, p. 22–27.

Goolsby, S.M., Reade, N.S., and Murray, D.K., 1979, Evaluation of coking coals in Colorado: Department of Natural Resources Colorado Geological Survey Resource Series 7, 72 p.

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Lee, W.T., 1912, Coal fi elds of Grand Mesa and the West Elk Mountains, Colorado: U.S. Geological 

Survey Bulletin 510, 237 p.

Murray, D.K., 1980, Coal in Colorado, in Kent, H.C., and Porter, K.W., eds., Colorado Geology: Rocky 

Mountain Association of Geologists, p. 205–216.

Murray, D.K., Fender, H.B., and Jones, D.C., 1977, Coal and methane gas in the southeastern part of 

the Piceance Creek Basin, Colorado, in Veal, H.K., ed., Exploration Frontiers of the Central and 

Southern Rockies: Rocky Mountain Association of Geologists, 1977 Symposium, p. 379–405.

Toenges, A.L., Dowd, J.J., Turnbull, L.A., Davis, J.D., Smith, H.L., and Johnson, V.H., 1949, Reserves, 

petrographic and chemical characteristics, and carbonizing, properties of coal occurring south of 

Dry Fork of Minnesota Creek, Gunnison County, near Paonia, Colo., and the geology of the area: 

U.S. Bureau of Mines Technical Paper 721, 48 p.

Toenges, A.L., Turnbull, L.A., Davis, J.D., Reynolds, D.A., Parks, B.C., Cooper, H.M., and Abernethy, 

R.F., 1952, Coal deposit, Coal Creek District, Gunnison County, Colo.: Reserves, coking properties, 

and petrographic and chemical characteristics: U.S. Bureau of Mines Bulletin 501, 83 p. 

Tremain, C.M., Hornbaker, A.L., Holt, R.D., and Ladwig, L.R., 1996, 1995 summary of coal resources 

in Colorado: Colorado Geological Survey Department of Natural Resources Special Publication 

41, 19 p.

Table. Coal in Mesaverde Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

2.4-29.9 0.3-3.2 8,160-14,380 
B28 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Tongue Mesa Coal Field

Location

The fi eld is located in parts of Gunnison, Montrose, and Ouray, Counties, in southwestern Colorado and is partly within the Uncompahgre National Forest. The following 

information is taken from Hettinger and others (in press).

Stratigraphy

The coal is present within an isolated remnant of Upper Cretaceous rocks in the 

northern San Juan Mountains. These strata were referred to as the Mesaverde Formation 

by Landis (1959). The geology of the fi eld was mapped by Dickinson (1987a, 1987b, 

1988) and he reassigned about 200 ft of coal-bearing strata to the Fruitland Formation. 

Landis (1959) described the area as being concealed by heavy vegetation, landslides, 

talus, and glacial deposits.

Table. Stratigraphy—Tongue Mesa coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Kirtland Shale alluvial plain 1,000 

Fruitland Formation coastal plain; major coal 200 

Pictured Cliffs Sandstone nearshore marine 50-250 

Coal Deposits

The Fruitland is exposed at a few localities and is buried to a depth of as much as 

2,500 ft (Dickinson, 1987a, 1987b, 1988). The Fruitland contains one laterally extensive 

coal bed that ranges from about 20 to 40 ft in thickness, and the formation contains 3 to 5 

additional coal beds that are about 5 to 13 ft thick. Dickinson states that the coal-bearing 

strata were drilled for Federal permits and leases but the data was not available to him.

Coal Quality

Coal in the Tongue Mesa coal fi eld has an ash yield of 6.7 to 8.4 percent, a 

sulfur content of 0.5 to 0.9 percent, and a calorifi c value of 9,350 to 10,200 Btu/lb 

on an as-received basis (Hornbaker and others, 1976). The apparent rank of the coal 

is subbituminous B (U.S. Bureau of Mines, 1937, p. 110–111) and subbituminous C 

(Dickinson, 1987a, 1987b, 1988).

Resources

Landis (1959) estimated that a 58-square-mile area of the Tongue Mesa fi eld contained a coal resource of about 2,355 million short tons. Hornbaker and others (1976) 

thought the resources could be as high as 4,000 million short tons, apparently based on 

drilling information.

Production History 

Underground mining took place in the Tongue Mesa coal fi eld between the 1890’s 

and 1940’s (Murray, 1981) and numerous small mines operated in the area (Dickinson, 

1987a, 1988).
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B29

References

Dickinson, R.G., 1987a, Geologic map of the Buckhorn Lakes quadrangle, Gunnison, Montrose, and 

Ouray Counties, Colorado: U.S. Geological Survey Geologic Quadrangle Map GQ-1642, scale 

1:24,000.

Dickinson, R.G., 1987b, Geologic map of the Washboard Rock quadrangle, Gunnison, Montrose, 

and Ouray Counties, Colorado: U.S. Geological Survey Geologic Quadrangle Map GQ-1643, scale 

1:24,000.

Dickinson, R.G., 1988, Geologic map of the Courthouse Mountain quadrangle, Gunnison, Hinsdale, 

and Ouray Counties, Colorado: U.S. Geological Survey Geologic Quadrangle Map GQ-1644, scale 

1:24,000.

Hettinger, R.D., Roberts, L.N.R., and Kirschbaum, M.A., in press, Investigations of the distribution and 

resources of coal in the Grand Mesa, Gunnison, and Uncompahgre National Forests, Colorado, 

in Bankey, V., ed., Resource Assessment and Geology of the Grand Mesa, Uncompahgre, and 

Gunnison National Forests and surrounding areas, Colorado: U.S. Geological Survey Professional 

Paper.

U.S. Bureau of Mines, 1937, Analyses of Colorado coals: U.S. Bureau of Mines Technical Paper 

575, 327 p.

Hornbaker, A.L., Holt, R.D., and Murray, K.D., 1976, Summary of coal resources in Colorado, 1975: 

Colorado Geological Survey Special Publication 9, 17 p. 

Landis, E.R., 1959, Coal Resources of Colorado: U.S. Geological Survey Bulletin 1072-C, p. 131–232.

Murray, D.K., 1981, Upper Cretaceous (Campanian) coal resources of western Colorado, in Epis, R.C. 

and Callender, J.F., eds., Western Slope Colorado: New Mexico Geological Society Guidebook, 

32nd Field conference, p. 233–239.
B30 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Yampa Coal Field

Location

The fi eld is located in parts of Moffat, Routt, and Rio Blanco Counties in northwestern Colorado. The fi eld is located on the southern margin of the Sand Wash Basin, which 

is part of the Greater Green River Basin. The stratigraphy is closely related to rocks in 

the Piceance Basin.

Stratigraphy

The fi rst major reconnaissance report on coal in the Yampa coal fi eld was published 

by Fenneman and Gale (1906). They introduced the term Mesaverde to the area and 

named the coal groups in what would later become the Iles and Williams Fork Formations. The geology, stratigraphy, and coal geology were studied in detail by Campbell 

(1923), Hancock (1925), and Bass and others (1955). A bibliography of the geology of 

the area was completed by Johnson and Brownfi eld (1984). Thicknesses of units are from 

Bass and others (1955) from measurements taken on the eastern side of the coal fi eld.

Table. Stratigraphy—Yampa coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Fort Union Formation fluvial; coal 1,400 

Lance Formation fluvial; minor coal 800-1,250 

Fox Hills Sandstone nearshore marine 250 

Lewis Shale marine 1,500 

Mesaverde Group nearshore marine; coastal plain 

 Williams Fork 

 Formation major coal 1,100-2,000 

 Iles Formation minor coal 1,500 

Mancos Shale marine 4,900 

Coal Deposits

Coal is present in the Cretaceous Iles, Williams Fork, and Lance Formations and in 

the Tertiary Fort Union Formation (Bass and others, 1955). The main coal groups were 

named the lower, middle, and upper by Fenneman and Gale (1906). The lower coal group 

is in the Iles, and the middle and upper coal groups are in the Williams Fork. The most 

economically important coal is restricted to the middle and upper groups. Thick beds are 

present in the Fort Union but are not currently being mined.

Upper Coal Group.—The upper coal group consists of about nine coal zones, in 

ascending order K–S, in a succession of strata from 200 to 850 ft thick (Bass and others, 

1955; Johnson and others, chap. P, this CD-ROM).

Middle Coal Group.—In outcrops on the eastern side of the fi eld, Bass and others 

(1955) defi ned three coal beds within the middle coal group; in ascending order, Wolf 

Creek, Wadge, and Lennox. On the western side of the fi eld, subsurface studies indicate 

that there are more than six major zones named A through H within a succession of strata 

as thick as 1,000 ft (Johnson and Brownfi eld, 1988).

Coal Quality

Most coal beds in the lower and middle coal groups have apparent ranks of highvolatile bituminous C, and coals in the upper coal group are subbituminous A (Hornbaker 

and others, 1976). Coal in the Lance and Fort Union are thought to be subbituminous B 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B31

and C (Murray, 1981). The following table gives averages for the Cretaceous coal-bearing 

units in the fi eld from Murray (1981). Within the Williams Fork Formation, the middle 

coal group has ash contents that range from 3.0 to 20.2 percent and sulfur contents that 

range from 0.3 to 0.9 percent; the upper coal group has ash contents that range from 4.1 to 

6.5 percent and sulfur contents that range from 0.5 to 0.7 percent.

Table. Coal in Lance Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

4.1-17.2 0.5-0.7 9,660-9,720 

Table. Coal in Williams Fork Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

3.0-20.3 0.3-1.8 9,800-12,440 

Table. Coal in Iles Formation. 

[Values reported on an as-received basis]

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

4.3-11.3 0.3-0.9 11,090-12,560 

Resources

Total original resources for all coal-bearing units, ranging in rank from subbituminous C to high-volatile bituminous B, in areas with less than 6,000 ft of overburden equal 

about 58 billion short tons (Hornbaker and others, 1976). Landis (1959) estimated about 

24 billion short tons of coal for beds in areas under less than 3,000 ft of overburden. 

Production History

More than 70 coal mines produced coal historically from the Yampa fi eld (Hornbaker 

and others, 1976). Numerous small mines produced from the lower coal group of the Iles, 

mainly in the Oak Creek area (Bass and others, 1955). Mines have produced from surface 

and underground operations in the middle and upper coal group since the early 1900’s 

(Fenneman and Gale, 1906).

References

Bass, N.W., Eby, J.B., and Campbell, M.R., 1955, Geology and mineral fuels of parts of Routt and 

Moffat Counties, Colorado: U.S. Geological Survey Bulletin 1027-D, p. 143–250.

Campbell, M.R., 1923, The Twentymile Park district of the Yampa coal fi eld, Routt County, Colorado: 

U.S. Geological Survey Bulletin 748, 82 p.

Fenneman, N.M., and Gale, H.S., 1906, The Yampa coal fi eld, Routt County, Colorado: U.S. Geological 

Survey Bulletin 297, 96 p.
B32 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Hancock, E.T., 1925, Geology and coal resources of the Axial and Monument Butte quadrangles, 

Moffat County, Colorado: U.S. Geological Survey Bulletin 757, 134 p.

Hornbaker, A.L., Holt, R.D., and Murray, D.K., 1976, 1975 summary of coal resources in Colorado: 

Colorado Geological Survey Special Publication No. 9, 17 p.

Johnson, E.A., and Brownfi eld, M.E., 1984, Selected references on the geology of the Yampa coal 

fi eld and Sand Wash Basin, Moffat, Routt, and Rio Blanco Counties, Colorado: U.S. Geological 

Survey Open-File Report 84-769, 42 p.

Johnson, E.A., and Brownfi eld, M.E., 1988, Regional correlation of the middle coal group of the 

Upper Cretaceous Mesaverde Group, Yampa coal fi eld, Moffat and Routt Counties, Colorado: U.S. 

Geological Survey Coal Investigations Map C-123.

Landis, E.R., 1959, Coal resources of Colorado: U.S. Geological Survey Bulletin 1072-C, p. 131–232.

Murray, D.K., 1981, Upper Cretaceous (Campanian) coal resources of western Colorado, in Epis, R.C. 

and Callender, J.F., eds., Western Slope Colorado: New Mexico Geological Society Guidebook, 

32nd Field conference, p. 233–239.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B33

New Mexico

Barker Creek Coal Field

Location

The Barker Creek fi eld is located in San Juan County in northwestern New Mexico 

and extends from the Colorado/New Mexico State line to the line between T. 30 N. 

and T. 31 N. (Hoffman, 1996) where the dip of the strata steepens near the Hogback 

monocline.

Stratigraphy

The area was mapped and the stratigraphy and coal geology were studied by Hayes 

and Zapp (1955), who provided thickness data for the northern part of the area. All units 

thicken to the south.

Table. Stratigraphy—Barker Creek coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Cliff House Sandstone nearshore marine 350 

Menefee Formation 

 upper coastal plain; major coal 250 

 middle alluvial plain 280 

 lower coastal plain; major coal 100 

Point Lookout Sandstone nearshore marine <350 

Coal Deposits

Hayes and Zapp (1955) recognized lower and upper coal zones. Composite thicknesses are as much as 17.3 ft for the lower zone and as much as 19.2 ft for the upper zone 

as reported by Shomaker (1971).

Coal Quality

The apparent rank of these coals is high-volatile bituminous C. The average sulfur 

content is 0.9 percent, and the average ash content is about 7 percent (Hoffman, 1996).

Table. Coal in Menefee Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 7.03 0.9 11,497 

Standard deviation 4.06 0 689 

Number of analyses 3 1 3 
B34 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Hoffman (1996) reported a demonstrated resource of about 20 million short tons for 

the lower zone and a resource of 48 million short tons for the upper coal zone (within 200 

ft of the surface and greater than 2.33 ft thick). Hayes and Zapp (1955) provided a more 

detailed breakdown of the resource in the Menefee by township and range in categories 

greater than 1.2 ft thick to a depth of 3,000 ft of overburden.

Production History

The area had one mine and a few prospect pits in the years between 1882 and 1905 

(Nickelson, 1988).

References

Hayes, P.T., and Zapp, A.D., 1955, Geology and fuel resources of the Upper Cretaceous rocks of the 

Barker dome–Fruitland area, San Juan County, New Mexico: U.S. Geological Survey Oil and Gas 

Investigations Map OM-144, scale 1:62,500.

Hoffman, Gretchen K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and 

Mineral Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000. 

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Shomaker, J.W., 1971, Mesa Verde, Durango, and Barker Creek Mesaverde areas, in Shomaker, 

J.W., Beaumont, E.C., and Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the 

San Juan Basin in New Mexico and Colorado: New Mexico State Bureau of Mines and Mineral 

Resources Memoir 25, p. 45–46.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B35

Bisti Coal Field

Location

The Bisti fi eld is located in San Juan County, northwestern New Mexico. The fi eld 

extends from the boundary of the Navajo Indian Reservation on the west to the boundary 

between R. 8 W. and R. 9 W. on the east (Shomaker, 1971). The Bisti and De-Na-Zin 

Wilderness areas are located within the fi eld.

Stratigraphy

The fi rst detailed study of the stratigraphy and coal geology of the fi eld was by 

Bauer and Reeside (1921). The thickest coals are in the Fruitland Formation. Thickness 

of the Pictured Cliffs Sandstone was measured at Meyers Creek and Escavada Wash; the 

Fruitland thickness is from the Meyers Creek area; and the Kirtland Shale thickness is 

from Escavada Wash (Bauer and Reeside, 1921).

Table. Stratigraphy—Bisti coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Kirtland Shale alluvial plain 700 

Fruitland Formation coastal plain; major coal 196 

Pictured Cliffs Sandstone nearshore marine 70-91 

Coal Deposits

There are three main beds (zones)—named lower, middle, and upper—in the lower 

150 ft of the Fruitland in the Bisti area (Shomaker, 1971, fi g. 50). Within a fourquadrangle (7.5′) area within the Bisti fi eld, four recognizable coal zones are present. In 

ascending order, they are the red, green, blue, and yellow (Hoffman and Jones, 1998). 

These coals were fi rst named by Conpaso for that company’s Burnham mine area (G.K. 

Hoffman, New Mexico Bureau of Mines and Economic Geology, written commun., 

1999). The thickest coals are 3.9 to 32.0 ft thick (Shomaker, 1971, based in part on Bauer 

and Reeside, 1921).

Coal Quality

The coal is subbituminous in rank, and is relatively high in ash (10.1–35.1 percent 

as-received) and low in sulfur content (0.3–0.8 percent as-received) (Shomaker, 1971, 

table 11). Average ash, sulfur, and heat contents in the following table are from Hoffman 

(1996).

Table. Coal in Fruitland Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 19.29 0.52 8,754 

Standard deviation 5.42 0.09 883 

Number of analyses 44 44 44 
B36 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

The Fruitland Formation in the Bisti area is estimated to contain about 1,870 million 

short tons of coal under less than 250 ft of overburden (Shomaker, 1971). A coalavailability study of a four-quadrangle area within the fi eld demonstrates that there is 

about 5.1 billion shorts tons of coal present in four zones, and, of that amount, about 60 

percent is available for mining consideration (Hoffman and Jones, 1998).

Production History

The fi eld has had a number of leases and permits issued since 1961. Two mines, 

the De-Na-Zin and the Gateway have operated in the area but became inactive in 1988 

(Hoffman, 1996). The De-Na-Zin mine had peak production of about 230,000 short tons 

of coal in 1982 (Nickelson, 1988).

References

Bauer, C.M., and Reeside, J.B., Jr., 1921, Coal in the middle and eastern parts of San Juan County, 

New Mexico: U.S. Geological Survey Bulletin 716-G, p. 155–237.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Hoffman, G.K., and Jones, G.E., 1998, Availability of coal resources in the Fruitland Formation, San 

Juan Basin, northwest New Mexico: New Mexico Bureau of Mines and Mineral Resources Open 

File Report 438, 15 p.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Shomaker., J.W., 1971, Bisti Fruitland fi eld, in Shomaker, J.W., Beaumont, E.C., and Kottlowski, F.E., 

eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico and Colorado: 

New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 110–117.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B37

Chaco Canyon Coal Field

Location

The fi eld is located in San Juan and McKinley Counties, New Mexico, in the 

southern part of the San Juan Basin. The southern edge of the fi eld is defi ned by the 

limit of upper Menefee Formation coal outcrops, which are just below the overlying Cliff 

House Sandstone (Lease, 1971). The western boundary is the edge of the Navajo Indian 

Reservation coincident with the west edge of R. 13 W. The eastern boundary is shared 

by the Chacra Mesa coal fi eld at the west edge of R. 8 W. The fi eld has two subareas, 

from west to east: La Vida mission and Chaco Canyon (encompassing Chaco Culture 

National Historic Park).

Stratigraphy

The eastern part of the area was fi rst mapped in detail by Dane (1936), and the Chaco 

Canyon area was later mapped in detail by Scott and others (1984). Subsurface mapping 

of the coal in the La Vida Mission area is shown by Lease (1971, fi g. 21). The coals are 

in the upper coal member of the Menefee Formation, which changes facies into the La 

Ventana Tongue of the Cliff House Sandstone to the east. Coals are also present in the 

subsurface in the Cleary Coal Member of the Menefee (called Gibson Coal Member of 

the Mesaverde Formation by Dane, 1936). Thickness of the Cliff House Sandstone is from 

Dane (1936); thickness of the Menefee is from Scott and others (1984).

Table. Stratigraphy—Chaco Canyon coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Cliff House Sandstone nearshore marine; coastal plain; minor coal 340+ 

Menefee Formation 1,500 

 upper coal member coastal plain; coal 

 Allison Member alluvial plain 

 Cleary Coal Member coastal plain; coal 

Coal Deposits

Coals in the fi eld are as thick as 6.5 ft in the Chaco and La Vida Mission areas 

(Lease, 1971). In the La Vida Mission subarea, a pod of coal greater than 6 ft thick 

extends across parts of four sections under less than 150 ft of overburden (Lease, 1971, 

fi g. 21)

Coal Quality

The upper-member coals are subbituminous A in apparent rank (Hoffman, 1996). 

The following table is from Hoffman (1996).

Table. Coal in upper coal member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 7.88 1.63 10,210 

Standard deviation 2.00 1.13 17 

Number of analyses 4 4 4 
B38 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

The Chaco Canyon fi eld contains about 16 million short tons of coal in beds greater 

than 2.5 ft thick and within 200 ft of the surface (Hoffman, 1996; also see Lease, 1971). 

The fi eld also contains an additional 83 million short tons of underground resource; 51 

million short tons in the upper coal member and 32 million short tons in the Cleary Coal 

Member (Hoffman, 1996).

Production History

The Chaco Canyon fi eld contained two small mines that operated sometime between 

1900 and the 1920’s (Nickelson, 1988).

References

Dane, C.H., 1936, The La Ventana–Chacra Mesa coal fi eld, in Sears, J.D., Hunt, C.B., and Dane, C.H., 

eds., Geology and Fuel Resources of the Southern Part of the San Juan Basin: U.S. Geological 

Survey Bulletin 860-C, p. 81–166.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Lease, R.C., 1971, Chaco Canyon upper Menefee area, in Shomaker, J.W., Beaumont, E.C., and 

Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico 

and Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 52–56.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Scott, G.R., O’Sullivan, R.B. and Weide, D.L. 1984, Geologic map of the Chaco Culture National 

Historical Park, northwestern New Mexico: U.S. Geological Survey Miscellaneous Investigations 

Map I-1571.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B39

Chacra Mesa Coal Field

Location

The fi eld is located in McKinley and Sandoval Counties, New Mexico, in the 

southern part of the San Juan Basin. The southern edge of the fi eld is defi ned by the 

limit of upper Menefee Formation coal outcrops, which are just below the overlying Cliff 

House Sandstone (Speer, 1971). The western boundary is the Chaco Canyon coal fi eld. 

The eastern boundary is shared with the La Ventana fi eld at R. 3 W.

Stratigraphy

The areas were fi rst mapped in detail by Dane (1936). The coals are in the upper 

coal member of the Menefee Formation, which changes facies into the La Ventana Tongue 

of the Cliff House Sandstone to the east, and coals are present in the subsurface in the 

Cleary Coal Member of the Menefee (called upper part of the Gibson Coal Member of the 

Mesaverde Formation by Dane). Minor coals are present in the Cliff House (Speer, 1971). 

The thickness of the Cliff House Sandstone is from Dane (1936). The thicknesses of the 

Menefee units are from Tabet and Frost (1979).

Table. Stratigraphy—Chacra Mesa coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Cliff House Sandstone nearshore marine; coastal plain; minor coal 360 

Menefee Formation 

 upper coal member coastal plain; coal 650 

 Allison Member alluvial plain 400-550 

 Cleary Coal Member coastal plain; coal 200-300 

Coal Deposits

The coals are as thick as 13.7 ft in the Chacra Mesa fi eld, but they are generally 

less than 6 ft thick (Tabet and Frost, 1979). The maximum thickness observed on outcrop 

was 3.8 ft (Speer, 1971).

Coal Quality

The Cleary and upper-member coals are subbituminous A to high-volatile C bituminous in apparent rank. The following table is from Hoffman (1996) and is based on data 

collected in Roybal and others (1987, 1988).

Table. Coal in upper coal member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 9.69 0.72 10,207 

Standard deviation 3.29 0.41 615 

Number of analyses 14 14 14 
B40 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

The Chacra Mesa fi eld contains an estimated 269 million short tons of demonstrated 

underground resources (Hoffman, 1996).

Production History

Four small mines operated in the fi eld between 1933 and 1958 (Nickelson, 1988).

References

Dane, C.H., 1936, The La Ventana–Chacra Mesa coal fi eld, in Sears, J.D., Hunt, C.B. and Dane, C.H., 

eds., Geology and Fuel Resources of the Southern Part of the San Juan Basin: U.S. Geological 

Survey Bulletin 860-C, p 81–166.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Roybal, G.H., Campbell, F.W., Beaumont, E.C., Cohen, A.D., Kuellmer, F.J., Kottowski, F.E., and Cook, 

K., 1987, Quality assessment of strippable coals in New Mexico, Year 2, Phase II, Fruitland and 

Menefee and Crevasse Canyon Formation coals in the San Juan Basin of northwestern New 

Mexico: New Mexico Research and Development Institute, Report 2-73-4331, 90 p.

Roybal, G.H., Campbell, F.W., Beaumont, E.C., Bellis, D., Kottlowski, F.E., and Cohen, A.D., 1988, Quality 

assessment of strippable coals in New Mexico, Year 3, Phase II, Menefee and Crevasse Canyon 

and Moreno Hill Formation coals in the San Juan Basin of northwestern New Mexico and the Salt 

Lake coal fi eld: New Mexico Research and Development Institute, Report 2-76-5310, 100 p.

Speer, W.R.., 1971, Chacra Mesa Menefee area, in Shomaker, J.W., Beaumont, E.C., and Kottlowski, 

F.E., eds. Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico and 

Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 56–64.

Tabet, D.E., and Frost, S.J., 1979, environmental characteristics of Menefee coals in the Torreon 

Wash area, New Mexico: New Mexico Bureau of Mines and Mineral Resources Open-File Report 

102, 134 p.

Table. Coal in Cleary Coal Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 11.05 0.45 10,898 

Standard deviation 2.57 0.11 1,605 

Number of analyses 2 2 2 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B41

Crownpoint Coal Field

Location

The Crownpoint coal fi eld is located on the south side of the San Juan Basin in 

McKinley County, New Mexico. The Crownpoint fi eld encompasses the outcrops of the 

Crevasse Canyon Formation from the northeastern edge of the Gallup fi eld to the west 

edge of the San Mateo fi eld.

Stratigraphy

The fi rst comprehensive study of the coal geology and stratigraphy was by Sears 

(1934). The Gibson Coal Member of the Crevasse Canyon Formation was studied in the 

subsurface by Campbell and Roybal (1987) and Hoffman (1993). Thicknesses of units are 

from Sears (1934, text and plate 1).

Table. Stratigraphy—Crownpoint coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Crevasse Canyon Formation 

 Gibson Coal Member coastal plain; major coal 140-300 

 Bartlett Barren 

 Member alluvial plain 0-270 

 Dalton Sandstone 

 Member nearshore marine 180 

Mancos Shale 

 Mulatto Tongue marine 0-220 

Crevasse Canyon Formation 

 Dilco Coal Member coastal plain; coal 148-200 

Gallup Sandstone nearshore marine; coastal plain; coal 80-320 

Coal Deposits

Numerous thin beds are present in the Dilco Coal Member of the Crevasse Canyon 

Formation and Gallup Sandstone (Sears, 1934). The thickest coals are in the Gibson Coal 

Member of the Crevasse Canyon Formation. Within the Gibson, coals are as thick as 12 

ft on outcrop (Sears, 1934, plate 13). In the subsurface, the Gibson coals are in zones 

of 3 to 13 beds, and individual beds are as thick as 6 ft (Campbell and Roybal, 1987; 

Hoffman, 1993).

Coal Quality

The Gibson coals are subbituminous B–A and average about 12 percent ash and 

about 1.4 percent sulfur on an as-received basis (Hoffman, 1996). The table below is 

from Hoffman (1996).

Table. Coal in Gibson Coal Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 11.95 1.44 10,037 

Standard deviation 5.29 0.73 923 

Number of analyses 13 13 13 
B42 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

The Gibson Coal Member contains about 663 million short tons of demonstrated 

resources in areas with less than 200 ft of overburden (Hoffman, 1996). The Gibson may 

contain as much as 15 million short tons of strippable coal (Shomaker, 1971).

Production History

Eleven mines or prospects operated in the coal fi eld between 1918 and 1963 (Nickelson, 1988).

References

Campbell, F.W., and Roybal, G.H., 1987, Characterization of New Mexico coals, Menefee and Crevasse Canyon Formations, in Roybal, G.H., Anderson, O.J., and Beaumont, E.C., eds., Coal Deposits and Facies Changes Along the Southwestern Margin of the Late Cretaceous Seaway, WestCentral New Mexico: New Mexico Bureau of Mines and Mineral Resources Bulletin 121, p. 

41–48.

Hoffman, G.K., 1993, Description of coal-bearing sequences, in Hoffman, G.K., Campbell, F.W., and 

Beaumont, E.C., eds., Quality Assessment of Strippable Coals in Northwestern New Mexico: 

Fruitland, Menefee, and Crevasse Canyon Formation Coals in the San Juan Basin, and Moreno 

Hill Formation Coals in Salt Lake Field: New Mexico Bureau of Mines and Mineral Resources 

Bulletin 141, p. 17–53.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Sears, J.D., 1934, The coal fi eld from Gallup eastward toward Mount Taylor fi eld, in Sears, J.D., Hunt, 

C.B., and Dane, C.H., eds., Geology and Fuel Resources of the Southern Part of the San Juan 

Basin: U.S. Geological Survey Bulletin 860-A, p. 1–29.

Shomaker, J.W., 1971, Crownpoint Crevasse Canyon area, in Shomaker, J.W., Beaumont, E.C., and 

Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico 

and Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 81–87.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B43

Datil Mountains Coal Field

Location

The Datil Mountains coal fi eld is located on the southeastern edge of the Colorado 

Plateau in Catron, Cibola, and Socorro Counties, New Mexico.

Stratigraphy

An early study of the coal geology was by D.E. Winchester of the USGS, but this 

work was never published according to Pike (1947). Winchester (1920) did place the coal 

into a stratigraphic context and called the coal-bearing unit the Chamiso Formation. The 

stratigraphy in current usage was worked out by Pike (1947) and modifi ed by Maxwell 

(1976). Coal is present in the Dilco Coal Member of the Crevasse Canyon Formation 

(Frost and others, 1979).

Table. Stratigraphy—Datil Mountains coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mancos Shale (Mulatto 

 Tongue) marine 100 

Crevasse Canyon Formation 

 (part) 

 

 Dilco Coal Member coastal plain; coal 173 

Gallup Sandstone nearshore marine 27 

Coal Deposits

Most coal beds are generally less than 3 ft thick (Hoffman, 1996) but can be as thick 

as 4.5 ft (Frost and others, 1979).

Coal Quality

The coal in this fi eld has an average apparent rank of subbituminous A; average ash 

content is about 13 percent, and average sulfur is about 0.7 percent on an as-received 

basis (Hoffman, 1996).

Table. Coal in Dilco Coal Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 12.84 0.72 11,465 

Standard deviation 6.34 0.54 869 

Number of analyses 10 10 10 
B44 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

About 47 million short tons of coal are estimated for the fi eld by Hoffman (1996), 

who incorporated both new data and data collected by Frost and others (1979) and Osburn 

(1982).

Production History

Five small mines operated between about 1917 and 1940 (Frost and others, 1979).

References

Frost, S.J., Tabet, D.E., and Campbell, F.W., 1979, Coal exploratory drilling in the Datil Mountains coal 

fi eld: New Mexico Bureau of Mines and Mineral Resources Open-File Report 111, 49 p.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Maxwell, C.H., 1976, Stratigraphy and structure of the Acoma region, New Mexico: New Mexico 

Geological Society Special Publication 6, p. 95–101.

Osburn, J.C., 1982, Geology and coal resources of three quadrangles in the central Datil Mountains 

coal fi eld, Socorro County, New Mexico: New Mexico Bureau of Mines and Mineral Resources 

Open-File Report 164, 82 p.

Pike, W.S., Jr., 1947, Intertonguing marine and nonmarine Upper Cretaceous deposits of New 

Mexico, Arizona and southwestern Colorado: Geological Society of America Memoir 24, 103 p.

Winchester, D.E., 1920, Geology of Alamosa Creek Valley, Socorro County, New Mexico, with special 

reference to the occurrence of oil and gas, in White, D., and Campbell, M.R., eds. [1921], Contributions to Economic Geology 1920, U.S. Geological Survey Bulletin 716, p. 1–15.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B45

Fruitland Coal Field

Location

This coal fi eld is located in San Juan County in northwestern New Mexico and 

encompasses the outcrops of the Fruitland Formation between the New Mexico–Colorado 

State line and the San Juan River. The fi eld history is summarized by Beaumont (1971), 

Nickelson (1988), and Hoffman (1996).

Stratigraphy

The main coal deposits are in the Upper Cretaceous Fruitland Formation. Thicknesses of units are from Hayes and Zapp (1955) and Roberts (1991).

Table. Stratigraphy—Fruitland coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Kirtland Shale alluvial plain 1,160 

Fruitland Formation coastal plain; major coal 240-380 

Pictured Cliffs Sandstone nearshore marine 235-380 

Coal Deposits

Coal studies in the area include Bauer and Reeside (1921), Hayes and Zapp (1955), 

Shomaker and Holt (1973), and Roberts (1991). Important coal beds in the Fruitland 

include, in ascending order: the Main bed or lower split, Upper Main or upper split; 

Main bed or Carbonero bed, and the Ute Canyon or upper bed. The Main coal is located 

stratigraphically near the top of the underlying Pictured Cliffs Sandstone and ranges in 

thickness from about 14 ft, near the San Juan River, to about 30 ft thick at the La Plata 

mine (Nickelson, 1988).

Coal Quality

Coals of the Fruitland coal fi eld are calculated to have an apparent rank of highvolatile C and B bituminous (see discussion by Beaumont, 1971, p. 107). Average 

analyses of the coal are summarized from Hoffman (1996).

Table. Coal in Fruitland Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 17.95 0.8 9,786 

Standard deviation 5.69 0.3 1,954 

Number of analyses 105 103 105 
B46 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Demonstrated strippable coal resources within the fi eld are about 550 million short 

tons (defi ned as thicker than 2.33 ft and beneath less than 200 ft of overburden) (Hoffman, 

1996). Underground resources (200–1,000 ft of overburden) equal 861 million short 

tons (Hoffman, 1996). An estimated 100 million short tons of coal are distributed in 

three major beds in the Ute Mountain Ute Indian Reservation under less than 500 ft of 

overburden (Roberts, 1991).

Production History

Two mines presently operate within this coal fi eld: the San Juan mine in the south 

part of the fi eld and the La Plata mine in the north part of the fi eld. These mines produce 

coal for the San Juan generating station. The La Plata mine produced an average of about 

1.6 million short tons per year during a 5-year period between 1991 and 1995, and the San 

Juan mine produced an average of about 3.8 million short tons per year during the same 

period (G. Sullivan, written commun., 1997—compiled from Mine Safety and Health 

Administration data). The Ute Mountain Ute Tribal Nation owns coal that underlies an 

area of about 14.5 mi2

 between the two active mining operations. About 17 underground 

mines operated in the fi eld between 1898–1972 (Nickelson, 1988).

References

Bauer, C.M., and Reeside, J.B., Jr., 1921, Coal in the middle and eastern parts of San Juan County, 

New Mexico: U.S. Geological Survey Bulletin 716-G, p. 155–237.

Beaumont, E.C., 1971, Fruitland fi eld, in Shomaker, J.W., Beaumont, E.C., and Kottlowski, F.E., eds., 

Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico and Colorado: New 

Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 104–108.

Hayes, P.T., and Zapp, A.D., 1955, Geology and fuel resources of the Upper Cretaceous rocks of the 

Barker dome–Fruitland area, San Juan County, New Mexico: U.S. Geological Survey Oil and Gas 

Investigations Map OM-144, scale 1:62,500.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Roberts, L.N.R., 1991, Coal Resources of the Fruitland Formation in part of the Ute Mountain Ute 

Indian Reservation, San Juan County, Mew Mexico: U.S. Geological Survey Bulletin 1938, 15 p.

Shomaker, J.W., and Holt, R.D., 1973, Coal Resources of Southern Ute and Ute Mountain Ute Indian 

Reservations, Colorado and New Mexico: New Mexico State Bureau of Mines and Mineral 

Resources Circular 134, 22 p.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B47

Gallup Coal Field

Location

This fi eld is located in McKinley County, New Mexico within a southwestern extension of the San Juan Basin called the Gallup sag (Lease and Shomaker, 1971). The town 

of Gallup is located within the fi eld. The Gallup sag is bounded on the northwest by the 

Defi ance uplift, and on the southeast by the Nutria monocline. The coal fi eld is arbitrarily 

bounded on the south by the line between T. 11 N. and T. 12 N.

Stratigraphy

The earliest substantial work on the coal and stratigraphy was by Sears (1925). Summaries of the coal fi eld are provided by Lease and Shomaker (1971) and Hoffman (1996). 

A study of the relationship between the Gibson Coal Member of the Crevasse Canyon 

Formation and Cleary Coal Member of the Menefee Formation and interpretations of 

depositional environments is provided in Cavaroc and Flores (1984). Thicknesses of the 

Gibson Coal, Bartlett Barren, and Dilco Coal Members of the Crevasse Canyon and the 

Gallup Sandstone are from Sears (1925), based on his study of the Gallup and Zuni 

Basins. Thicknesses of the Point Lookout Sandstone and Cleary Coal Member are from 

Cavaroc and Flores (1984), and the thickness of the Dalton Sandstone Member of the 

Crevasse Canyon is from Sears and others (1941).

Table. Stratigraphy—Gallup coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Menefee Formation 

 Cleary Coal Member coastal plain; major coal 115 

Point Lookout Sandstone nearshore marine 0-65 

Crevasse Canyon Formation 

 Gibson Coal Member coastal plain; major coal 150-175 

 Bartlett Barren 

 Member coastal and alluvial plain 330-400 

 Dalton Sandstone 

 Member nearshore marine 0-180 

 Dilco Coal Member coastal plain; major coal 240-300 

Gallup Sandstone nearshore marine; minor coal 180-250 

Coal Deposits

Thick coals are present in the Dilco and Gibson Members of the Crevasse Canyon 

Formation and Cleary Member of the Menefee Formation. The Black Diamond bed of 

Sears (1925, p. 28) is the most extensive in the Dilco Member. There are four other thick 

coal zones in the Dilco (Hoffman, 1996). The Gibson and Cleary (combined where the 

Point Lookout Sandstone is not present) contains four thick coal zones (Hoffman, 1996), 

and all of the coal produced from the McKinley mine is from these beds—in ascending 

order, the green, blue, fuchsia, and yellow beds (Wilson, 1977).

Coal Quality

The apparent rank of the coals in the Dilco, Gibson, and Cleary Members are 

between high-volatile C bituminous and subbituminous A. The coals in the Cleary and 

Gibson average about 9 percent ash and contain about 0.5 percent sulfur; the Dilco coals 

contain about 9 percent ash and about 0.8 percent sulfur (Hoffman, 1996).
B48 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Remaining demonstrated coal resources in the Cleary and Gibson to a depth of 200 

ft equal 449 million short tons. Demonstrated coal resources in the Dilco under less than 

200 ft of overburden equal 161 million short tons (Hoffman, 1996).

Production History

Coal was produced historically from more than 85 mines in the Gallup coal fi eld 

from the Dilco, Gibson and Cleary Members and from the Gallup Sandstone (Nickelson, 

1988). At present, only the McKinley mine produces signifi cant amounts of coal from 

strip pits in the western part of the fi eld. The McKinley mine is located about 20 mi 

northwest of Gallup and has produced an average of 5.8 million short tons of coal per 

year over the period between 1991–1995 (G. Sullivan, written commun., 1997—compiled 

from Mine Safety and Health Administration data).

References

Cavaroc, V.V., and Flores, R.M., 1984, Lithologic relationships of the Upper Cretaceous Gibson-Cleary 

stratigraphic interval: Gallup coal fi eld, New Mexico, U.S.A., in Rahmani, R.A., and Flores, R.M., 

eds., Sedimentology of Coal and Coal-Bearing Sequences: International Association of Sedimentologists Special Publication 7, p. 197–216.

Lease, R.C., and Shomaker, J.W., 1971, Gallup Mesaverde fi eld, in Shomaker, J.W., Beaumont, E.C., 

and Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New 

Mexico and Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 36–56.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Sears, J.D., 1925, Geology and coal resources of the Gallup-Zuni Basin, New Mexico: U.S. Geological 

Survey Bulletin 767, 53 p.

Sears, J.D., Hunt, C.B., and Hendricks, T.A., 1941, Transgressive and regressive Cretaceous deposits 

in southern San Juan Basin, New Mexico: U.S. Geological Survey Professional Paper 193-F, p. 

101–121.

Wilson, J.C., 1977, The McKinley mine, in Fassett, J.E., ed., Guidebook of San Juan Basin III 

Northwestern New Mexico: New Mexico Geological Society 28th Field Conference, p. 253–255.

Table. Coal in Cleary and Gibson Coal Members. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 9.32 0.53 10,507 

Standard deviation 4.56 0.13 0.13 

Number of analyses 35 35 35 

Table. Coal in Dilco Coal Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 9.08 0.76 10,343 

Standard deviation 5.59 0.32 3,220 

Number of analyses 14 14 13 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B49

Hogback Coal Field

Location

The Hogback fi eld is located in northwest New Mexico on the fl ank of the San 

Juan Basin in San Juan County. The fi eld extends along the structure of the Hogback 

monocline from about T. 30 N. south to T. 26 N.

Stratigraphy

The coal geology of the northern part of the area was studied by Hayes and Zapp 

(1955), who provided thicknesses as measured at San Juan River exposures.

Table. Stratigraphy—Hogback coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Cliff House Sandstone nearshore marine 750 

Menefee Formation 1,000 

 upper coastal plain; major coal 

 middle alluvial plain 

 lower coastal plain; major coal 

Point Lookout Sandstone nearshore marine 350 

Coal Deposits

Coal is in the lower and upper zones of the Menefee Formation. The lower zone 

is poorly developed in the area but has a maximum aggregate coal thickness of 11.3 ft, 

and the upper zone contains as many as 10 individual beds with total coal as thick as 

38.2 ft (Lease, 1971).

Coal Quality

The average apparent rank of the coals in the Hogback fi eld is high-volatile C 

bituminous; the average ash content is about 16 percent and the average sulfur content is 

about 0.7 percent on an as-received basis (Hoffman, 1996).

Table. Coal in Menefee Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 15.68 0.7 10,053 

Standard deviation 11.08 0.2 1,533 

Number of analyses 3 3 3 
B50 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

The fi eld is estimated to have about 45 million short tons of coal in areas where the 

overburden is less than 200 ft; however, these resources may not be recoverable because 

of the steep dips of the strata (Lease, 1971; Hoffman, 1996).

Production History

The Hogback fi eld was mined between 1907 and 1976. More than 17 separate mines 

operated in the area until 1976. The largest, Hogback No. 13, produced less than 100,000 

short tons during its lifetime (Nickelson, 1988).

References

Hayes, P.T., and Zapp, A.D., 1955, Geology and fuel resources of the Upper Cretaceous rocks of the 

Barker dome–Fruitland area, San Juan County, New Mexico: U.S. Geological Survey Oil and Gas 

Investigations Map OM-144, scale 1:62,500.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Lease, R.C., 1971, Hogback Upper Menefee area, in Shomaker, J.W., Beaumont, E.C. and Kottlowski, 

F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico and 

Colorado: New Mexico State Bureau of Mines and Mineral Resources Memoir 25, p. 47.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B51

La Ventana Coal Field

Location

This coal fi eld is located in Sandoval County, New Mexico, on the southeastern edge 

of the San Juan Basin.

Stratigraphy

The fi rst comprehensive study of the geology and the coal deposits of this coal 

fi eld was by Dane (1936), and the complex intertonguing of the units was worked out 

by Beaumont and Hoffman (1992). The most up-to-date study of the area, concentrating 

on subsurface geology, is by Beaumont and Hoffman (1992), who show a maximum 

thickness of about 950 ft for the La Ventana. The thickness of the La Ventana Tongue 

given in the table below is based on Dane (1936, p.108). Thickness of the Menefee is 

also derived from Dane (1936), and is in good agreement with subsurface measurements 

reported by Beaumont and Hoffman (1992, fi g. 4). The thickness of the Point Lookout is 

from a sandstone measured and referred to by Dane (1936, p.99) as the Hosta sandstone 

member of the Mesaverde Formation.

Table. Stratigraphy—La Ventana coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Cliff House Sandstone 

 La Ventana Tongue nearshore marine 650-1,256 

Menefee Formation 667 

 upper coal member coastal plain; coal 

 Allison Barren 

 Member alluvial plain 

 Cleary Coal Member coastal plain; coal 

Point Lookout Sandstone nearshore marine 84 

Coal Deposits

Coal as thick as 8.5 ft is present mainly in the upper coal member of the Menefee 

Formation (Hoffman, 1993).

Coal Quality

The coals of the Cleary Coal Member of the Menefee Formation and the upper 

member are subbituminous in rank (Hoffman, 1996). Coals in the Cleary average about 

11 percent ash and about 1 percent sulfur (as-received), and coals in the upper member 

average about 8 percent ash and about 1.4 percent sulfur (Hoffman, 1996).

Table. Coal in upper coal member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 8.14 1.36 10,171 

Standard deviation 4.34 0.55 696 

Number of analyses 20 20 20 
B52 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

The upper coal member has about 130 million short tons of demonstrated resources 

with about 75 million short tons having less than 200 ft of overburden (Hoffman, 1996).

Production History

About 36 mines were operating in the La Ventana fi eld between 1884 and 1984 

(Nickelson, 1988; Hoffman, 1996).

References

Beaumont, E.C., and Hoffman, G.K., 1992, Interrelationships between the upper coal member of the 

Menefee Formation, the La Ventana Tongue, and the Lewis Shale in the southeastern San Juan 

Basin, New Mexico, in Lucas, S.G., Kues, B.S., Williamson, T.E., and Hunt, A.P., eds., San Juan 

Basin IV: New Mexico Geological Society Guidebook, 43rd Field Conference, p. 207–216.

Dane, C.H., 1936, The La Ventana–Chacra Mesa coal fi eld, in Sears, J.D., Hunt, C.B., and Dane, C.H., 

eds., Geology and Fuel Resources of the Southern Part of the San Juan Basin: U.S. Geological 

Survey Bulletin 860-C, p 81–166.

Hoffman, G.K., 1993, Description of coal-bearing sequences, in Hoffman, G.K., Campbell, F.W., and 

Beaumont, E.C., eds., Quality Assessment of Strippable Coals in Northwestern New Mexico: 

Fruitland, Menefee, and Crevasse Canyon Formation Coals in the San Juan Basin, and Moreno 

Hill Formation Coals in Salt Lake Field: New Mexico Bureau of Mines and Mineral Resources 

Bulletin 141, p.17–49. 

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Table. Coal in Cleary Coal Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 11.06 1.01 10,400 

Standard deviation 3.31 0.62 620 

Number of analyses 28 20 27 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B53

Monero Coal Field

Location

The Monero coal fi eld is located in Rio Arriba County and a small portion extends 

into Sandoval County in north-central New Mexico. The fi eld is structurally situated on 

the northeastern margin of the San Juan Basin.

Stratigraphy

A reconnaissance study of the coal was completed by Gardner (1909); however, the 

earliest detailed geology of the area was by Dane (1948) and the most recent work is by 

Hoffman (1991). Thicknesses of units are from Hoffman (1991), except for the Mancos 

Shale which is from Dane (1948).

Table. Stratigraphy—Monero coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mesaverde Group 

 Cliff House 

 Sandstone nearshore marine 125 

 Menefee Formation coastal plain; coal 0-110 

 Point Lookout 

 Sandstone nearshore marine 65-200 

Mancos Shale marine shale 2,060 

Coal Deposits

Individual coal beds attain a maximum thickness of about 5 ft (Hoffman, 1991, 

fi g. 8).

Coal Quality

The coals are high-volatile bituminous C to A in apparent rank, average about 10 

percent ash, and have about 1.8 percent sulfur on an as-received basis (Hoffman, 1991).

Table. Coal in Menefee Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 10.16 1.85 12,373 

Standard deviation 3.10 1.01 963 

Number of analyses 14 14 13 
B54 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Only about 8 million short tons of demonstrated resource is estimated for this fi eld 

in areas under less than 200 ft of overburden (Hoffman, 1996); the estimated original 

resource is 17 million short tons (Hoffman, 1991). 

Production History

About 40 mines operated in the fi eld between 1882–1963, producing 1.6 million 

short tons of coal (Hoffman, 1991).

References

Dane, C.H., 1948, Geologic map of part of eastern San Juan basin, Rio Arriba County, New Mexico: 

U.S. Geological Survey Oil and Gas Investigations Preliminary Map 78, 1 sheet.

Gardner, J.H., 1909, The coal fi eld between Gallup and San Mateo, New Mexico, in Campbell, M.R., 

ed., Contributions to Economic Geology 1907: U.S. Geological Survey Bulletin 341, p. 364–378.

Hoffman, G.K., 1991, Geology and quality of Menefee Formation coals, Monero coal fi eld, Rio Arriba 

County, New Mexico: New Geology, v. 13, no. 1, p. 1–21.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B55

Mount Taylor Coal Field

Location

This coal fi eld is located on the south and east side of the Mount Taylor volcanic 

complex in McKinley, Sandoval, and Cibola Counties, New Mexico. The original usage 

of the name Mount Taylor by Hunt (1936) also encompasses several other fi elds (see San 

Mateo and Rio Puerco fi elds). Much of the coal in the fi eld is overlain by lava fl ows 

associated with Mount Taylor.

Stratigraphy

The fi rst detailed mapping of the geology was completed by Hunt (1936) And 

the latest compilation of the geology and coal resources is by Dillinger (1989, 1990). 

Thicknesses of the units are from a compilation by Dillinger (1990).

Table. Stratigraphy—Mount Taylor coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Crevasse Canyon Formation 

 Gibson Coal Member coastal plain; minor coal 64-492 

 Dalton Sandstone 

 Member nearshore marine 40-213 

Mancos Shale 

 Mulatto Tongue marine shale 60-400 

Crevasse Canyon Formation 

 Dilco Coal Member coastal plain; minor coal 80-200 

Coal Deposits

Coals are present in the Gibson Coal and Dilco Coal Members of the Crevasse 

Canyon Formation in the southern Mount Taylor fi eld and only in the Gibson in the 

eastern part of the Mount Taylor fi eld. The beds are between 2.5 and 7.0 ft thick and 

are lenticular in nature (Kottlowski and Parkhill, 1971; Hoffman, 1996). Discontinuous 

coal beds in the eastern part of the Mount Taylor fi eld are as thick as 6.5 ft (Kottlowski 

and others, 1971).

Coal Quality

The coal is subbituminous A to high-volatile C bituminous (Kottlowski and Parkhill, 

1971; Hoffman, 1996). The Gibson and Dilco coals have a sulfur content of about 0.6 

percent and an ash content of about 6 percent based on only a few analyses (Hoffman, 

1996).

Resources

In the southern Mount Taylor fi eld, the Gibson contains about 14 million short tons 

of coal under less than 200 ft of overburden (Hoffman, 1996); the member contains about 

37 million short tons under less than 1,000 ft of overburden and in beds greater than 

3.5 ft thick (Dillinger, 1989). The Dilco contains no resources in beds greater than 3.5 

ft thick (Dillinger, 1989). No strippable coal is reported from the eastern Mount Taylor 

fi eld (Kottlowski and others, 1971).
B56 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Production History

The East Mount Taylor coal fi eld had four mines or prospects in operation between 

1924 and 1954, and the area showed some potential in the 1960’s; however, exploration 

drilling showed insuffi cient coal to allow further development (Nickelson, 1988).

References

Dillinger, J.K., 1989, Coal resources maps of the Grants 30’x60’ quadrangle, west-central New 

Mexico: U.S. Geological Survey Coal Investigations Map C118-B, scale 1:100,000.

Dillinger, J.K., 1990, Geologic map of the Grants 30’x60’ quadrangle, west-central New Mexico: U.S. 

Geological Survey Coal Investigations Map C118-A, scale 1:100,000.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Hunt, C.B., 1936, The Mount Taylor coal fi eld, in Sears, J.D., Hunt, C.B., and Dane, C.H., eds., Geology 

and Fuel Resources of the Southern Part of the San Juan Basin: U.S. Geological Survey Bulletin 

860-B, p. 31–80.

Kottlowski, F.E., and Parkhill, T.A., 1971, South Mount Taylor Crevasse Canyon area, in Shomaker, 

J.W., Beaumont, E.C., and Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the San 

Juan Basin in New Mexico and Colorado: New Mexico Bureau of Mines and Mineral Resources 

Memoir 25, p. 87–89.

Kottlowski, F.E., Beaumont, E.C., and Parkhill, T.A., 1971, East Mount Taylor Crevasse Canyon area, in

Shomaker, J.W., Beaumont, E.C., and Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources 

of the San Juan Basin in New Mexico and Colorado: New Mexico Bureau of Mines and Mineral 

Resources Memoir 25, p. 89–92.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B57

Navajo Coal Field

Location

The Navajo coal fi eld is located on the Navajo Indian Reservation within San Juan 

County in northwestern New Mexico. The fi eld extends from the San Juan River on the 

north to the eastern edge of the Navajo Reservation at the boundary between R. 14 W. 

and R. 13 W. (Shomaker, 1971).

Stratigraphy

The stratigraphy and coal geology was fi rst studied in detail by Bauer and Reeside 

(1921). The thickness of the Pictured Cliffs Sandstone was measured at Brimhall Wash, 

and the thickness of the Fruitland Formation was obtained at Cottonwood Arroyo (Bauer 

and Reeside, 1921).

Table. Stratigraphy—Navajo coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Kirtland Shale alluvial plain ~1,000 

Fruitland Formation coastal plain; major coal 330 

Pictured Cliffs Sandstone nearshore marine 49 

Coal Deposits

Bauer and Reeside (1921) mapped two continuous coal beds in the northern part of 

the fi eld and as many as fi ve fairly continuous coal beds in the central and southern parts 

of the fi eld. The coals dip at about 1 degree to the east into the San Juan Basin (Bauer and 

Reeside, 1921). The low dips keep the coal within 1,000 ft of the surface in a band about 

10 mi wide, east of the outcrop belt.

Coal Quality

Coals are subbituminous A to high-volatile C bituminous (Hoffman, 1996). Average 

ash, sulfur, and heat contents in the table below are from Hoffman (1996).

Table. Coal in Fruitland Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 19.29 0.79 9,124 

Standard deviation 3.23 0.27 647 

Number of analyses 39 37 39 
B58 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Demonstrated surface minable coal resources in the fi eld are about 1.3 billion short 

tons for beds greater than 2.5 ft and less than 200 ft of overburden (Hoffman, 1996).

Production History

The Navajo mine opened in 1963 and has produced high volumes of coal each 

year since (Hoffman, 1996) (average of 8.3 million short tons between 1991–1995—G. 

Sullivan, written commun., 1997—compiled from Mine Safety and Health Administration data). One other major operation, the Burnham mine, operated in the area from 

1978–1984.

References

Bauer, C.M., and Reeside, J.B., Jr., 1921, Coal in the middle and eastern parts of San Juan County, 

New Mexico: U.S. Geological Survey Bulletin 716-G, p. 155–237.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Shomaker, J.W., 1971, Navajo Fruitland fi eld, in Shomaker, J.W., Beaumont, E.C., and Kottlowski, F.E., 

eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico and Colorado: 

New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 108–110.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B59

Newcomb-Toadlena Coal Field

Location

These coal fi elds are located within San Juan County, New Mexico, on the western 

margin of the San Juan Basin and entirely within the Navajo Indian Reservation. The 

location is best shown by Shomaker (1971, his fi g. 17, p. 49).

Stratigraphy

Coal is present in the Menefee Formation. The geology of the Newcomb area 

was mapped and coal sections were measured by O’Sullivan (1955) and Beaumont and 

O’Sullivan (1955). Thickness measurements of the formations are not available for the 

following table.

Table. Stratigraphy—Newcomb-Toadlena coal field. 

Stratigraphic units Depositional environment 

Cliff House Sandstone nearshore marine sandstone 

Menefee Formation coastal plain; coal 

Point Lookout Sandstone nearshore marine sandstone 

Coal Deposits

In the Toadlena area, the coals are less than 2.5 ft thick in beds dipping as much as 

12 degrees, making them unsuitable for strip mining (Lease, 1971). In the Newcomb area, 

the coals have a maximum cumulative thickness in the range of 32–38 ft in 7 to 10 beds 

(Beaumont and O’Sullivan, 1955), with a maximum individual bed thickness of about 7 

ft (Shomaker, 1971). The coals are generally lenticular and unevenly distributed in the 

stratigraphic section (Shomaker, 1971).

Coal Quality

The coal is subbituminous A or B rank and generally contains less than 1 percent 

sulfur (Shomaker, 1971). The table below is summarized from Shomaker (1971, table 

3, p. 54).

Table. Coal in Menefee Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Range 6.6-22.7 0.5-1 .4 7,660-10,410 

Number of analyses 6 6 6 
B60 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

No resource estimates are available for the Toadlena area. The Newcomb area 

contains resources of about 72 to 78 million short tons of surface-minable coal under 

less than 200 ft of overburden and another 54 million short tons under less than 1,000 

ft of overburden that are potentially minable by underground methods (Shomaker, 1971; 

Hoffman, 1996).

Production History

No mining has taken place in either coal fi eld.

References

Beaumont, E.C., and O’Sullivan, R.B., 1955, Preliminary geologic map of the Kirtland quadrangle, San 

Juan County, New Mexico: U.S. Geological Survey Coal Investigations Map C-32.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Lease, R.C., 1971, Toadlena Upper Menefee area, in Shomaker, J.W., Beaumont, E.C., and Kottlowski, 

F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico and 

Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 47.

O’Sullivan, R.B., 1955, Preliminary geologic map of the Naschitti quadrangle, San Juan County and 

McKinley Counties, New Mexico: U.S. Geological Survey Coal Investigations Map C-31.

Shomaker, J.W., 1971, Newcomb Upper Menefee area, in Shomaker, J.W., Beaumont, E.C., and 

Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico 

and Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 47–52.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B61

Rio Puerco Coal Field

Location

The Rio Puerco coal fi eld is located at the southeastern edge of the San Juan Basin 

in Sandoval and Bernalillo and in parts of Cibola and Valencia Counties, New Mexico. 

Hunt (1936, plate 19) showed the area to be highly faulted and included the fi eld with 

the Mount Taylor coal fi eld.

Stratigraphy

Resources and coal information from Hunt (1936) is summarized by Shomaker 

(1971) and Hoffman (1996). The coal is thought to be in the Gibson Coal Member 

of the Crevasse Canyon Formation (Shomaker, 1971; Hoffman, 1996) although Hunt 

(1936) placed most of the coal in the upper Gibson member (Cleary Coal Member of 

the Menefee Formation according to present usage). Stratigraphic table (below) is, in 

part, from Sears and others (1941); thicknesses of units are approximated from Sears and 

others (1941, plate 26).

Table. Stratigraphy—Rio Puerco coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Menefee Formation 

 Cleary Coal Member coastal plain; coal 300+ 

Mancos Shale 

 Satan Tongue marine shale 0-350 

Mesaverde Formation 

 Hosta Sandstone 

 Member nearshore marine 0-200 

 Gibson Coal Member coastal plain; coal 0-200 

 Dalton Sandstone 

 Member nearshore marine 0-100 

Mancos Shale 

 Mulatto Tongue marine shale 200-500 

Mesaverde Formation 

 Dilco Coal Member coastal plain; minor coal 0-100 

 Gallup Sandstone 

 Member nearshore marine 0-50 

Coal Deposits

Coal is present in the Gibson Coal Member and is as thick as 9.6 ft with two 

partings (Hunt, 1936, plate 37), but individual coal beds generally average 3.8 ft thick 

(Hoffman, 1996).

Coal Quality

The rank of coals in the Gibson is subbituminous A to high-volatile C bituminous; 

the average ash content is about 8 percent and sulfur content is about 0.9 percent based on 

as-received analyses of just four samples (Hoffman, 1996).
B62 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

The Gibson is estimated to have demonstrated coal resources of about 25 million 

short tons (Hoffman, 1996).

Production History

Six small mines operated from the 1920’s into the 1940’s (Hoffman, 1996).

References

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Hunt, C.B., 1936, The Mount Taylor coal fi eld: U.S. Geological Survey Bulletin 860-B, p. 31–80.

Sears, J.D., Hunt, C.B., and Hendricks, T.A., 1941, Transgressive and regressive Cretaceous deposits 

in southern San Juan Basin, New Mexico: U.S. Geological Survey Professional Paper 193-F, p. 

101–121.

Shomaker, J.W., 1971, Rio Puerco Mesaverde area, in Shomaker, J.W., Beaumont, E.C., and Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico 

and Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, p. 92–96.

Table. Coal in Gibson Coal Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 8.35 0.93 9,445 

Standard deviation 1.71 0.41 203 

Number of analyses 4 4 4 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B63

Salt Lake Coal Field

Location

The fi eld is located in Cibola and Catron Counties in west-central New Mexico.

Stratigraphy

Regional stratigraphic relationships were worked out in detail by Hook and others 

(1983). Thickness of the Atarque Sandstone is from Hook and others (1983), and thickness of the Moreno Hill Formation is from McLellan and others (1983), Roybal and 

Campbell (1981), and Campbell (1987). The geology and distribution of coal was comprehensively mapped by Campbell (1981, 1989) and Roybal and Campbell (1981). The 

lower member of the Moreno Hill is equivalent to the Carthage member of the Tres 

Hermanos Formation.

Table. Stratigraphy—Salt Lake coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Moreno Hill Formation coastal/alluvial plain; coal 519-844 

 upper member alluvial plain; minor coal 350 

 middle member alluvial plain 60 

 lower member coastal plain; coal 490 

Atarque Sandstone nearshore marine 50-80 

Coal Deposits 

The major coal-bearing unit is the Moreno Hill Formation, although minor coal is 

present in the Dakota Sandstone (Campbell, 1987). There are four zones in the Moreno 

Hill: the Antelope, the Cerro Prieto, the Rabbit in the lower member, and the Twilight in 

the upper member (Campbell, 1987, 1989). The coals are as thick as 14 ft and average 

about 5 ft (Hoffman, 1996).

Coal Quality

The apparent rank of coal in the Moreno Hill is subbituminous A; the average 

ash content is about 17 percent and average sulfur content is about 0.7 percent on an 

as-received basis (Hoffman, 1996).

Table. Coal in Moreno Hill Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 17.07 0.69 9,166 

Standard deviation 4.07 0.22 837 

Number of analyses 58 52 56 
B64 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Resource estimates are summarized by Hoffman (1996) using data from Campbell 

(1981, 1989) and Roybal and Campbell (1981). The Moreno Hill contains about 323 

million short tons of coal in beds greater than 2.5 ft thick and under less than 200 ft 

of overburden.

Production History

The fi eld has had extensive exploration and some lease sales in the 1980’s. A test 

mine, the Fence Lake #1, was opened and produced about 100,000 short tons of coal but 

was shut down during 1987 (Hoffman, 1996). 

References

Campbell, F.W., 1981, Geology and coal resources of Cerro Prieto and the Dyke quadrangles: New 

Mexico Bureau of Mines and Mineral Resources Open-File Report 144, 44 p.

Campbell, F.W., 1987, Coal geology of the Salt Lake coal fi eld, in Roybal, G.H., Anderson, O.J., and 

Beaumont, E.C., eds., Coal Deposits and Facies Changes Along the Southwestern Margin of the 

Late Cretaceous Seaway, West-Central New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Bulletin 121, p. 65–71.

Campbell, F.W., 1989, Geology and coal resources of Fence Lake 1:50,000 quadrangle, New Mexico: 

New Mexico Bureau of Mines and Mineral Resources Geologic Map 62.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Hook, S.B., Molenaar, C.M., and Cobban, W.A., 1983, Stratigraphy and revision of nomenclature of 

upper Cenomanian to Turonian (Upper Cretaceous) rocks of west-central New Mexico, in Hook, 

S.B., ed., Contribution to Mid-Cretaceous Paleontology and Stratigraphy of New Mexico—Part II: 

New Mexico Bureau of Mines and Mineral Resources Circular 185, p. 7–28.

McLellan, M., Haschke, L., Robinson, L., Carter, M.D., and Medlin, A., 1983, Middle Turonian and 

younger Cretaceous rocks, northern Salt Lake coal fi eld, Cibola and Catron Counties, New 

Mexico, in Hook, S.B., ed., Contribution to Mid-Cretaceous Paleontology and Stratigraphy of New 

Mexico—Part II: New Mexico Bureau of Mines and Mineral Resources Circular 185, p. 41–47.

Roybal, G.H., and Campbell, F., 1981, Stratigraphic sequence and drilling data from Fence Lake area: 

New Mexico Bureau of Mines and Mineral Resources, Open-File Report 145, 28 p.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B65

San Mateo Coal Field

Location

The San Mateo coal fi eld is located in Ciboal, McKinley, and Sandoval Counties 

of northwestern New Mexico on the southeastern edge of the San Juan Basin (Pierce 

and Shomaker, 1971).

Stratigraphy

The fi rst coal reconnaissance work was by Gardner (1909), but the fi rst detailed 

geologic and stratigraphic study was by Hunt (1936). Hunt (1936) referred to the Cleary 

Coal Member of the Menefee Formation as the upper Gibson Coal Member. Thicknesses 

of units are from Hunt (1936) and Hoffman (1993, p. 37–38).

Table. Stratigraphy—San Mateo coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Menefee Formation 

 Cleary Coal Member coastal plain; coal 300+

Point Lookout Sandstone nearshore marine 200+ 

Coal Deposits

Coal is present in the Cleary Coal Member of the Menefee Formation, and the main 

coal beds are named blue and purple. The thickest coals are more than 15 ft (Beaumont, 

1987).

Coal Quality

Coal in the fi eld is subbituminous A in rank and averages about 13 percent ash and 

about 1 percent sulfur (Hoffman, 1996).

Table. Coal in Cleary Coal Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 13.14 0.93 9,865 

Standard deviation 3.46 0.35 1,088 

Number of analyses 45 45 45 
B66 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Demonstrated resources are estimated at about 450 million short tons in areas with 

less than 200 ft of overburden (Hoffman, 1996).

Production History

Historically there has been very little mining in the San Mateo coal fi eld; however, 

in 1984 the Lee Ranch mine opened and produced about 250,000 short tons in its fi rst 

year of operation (Nickelson, 1988). Cumulative production from 1984–1995, was around 

32 million short tons of coal (G. Sullivan, written commun., 1997—compiled from Mine 

Safety and Health Administration data).

References

Beaumont, E.C., 1987, Geology and mining activity in the Lee Ranch area, McKinley County, New 

Mexico, in Roybal, F.H., Anderson, O.J., and Beaumont, E.C., eds., Coal Deposits and Facies 

Changes Along the Southwestern Margin of the Late Cretaceous Seaway, West-Central New 

Mexico: New Mexico Bureau of Mines and Mineral Resources Bulletin 121, p. 37–40.

Gardner, J.H., 1909, The coal fi eld between Gallup and San Mateo, New Mexico, in Campbell, M.R. 

ed., Contributions to Economic Geology 1907: U.S. Geological Survey Bulletin 341, p. 364–378.

Hoffman, G.K., 1993, Description of coal-bearing sequences, in Hoffman, G.K., Campbell, F.W., and 

Beaumont, E.C., eds., Quality Assessment of Strippable Coals in Northwestern New Mexico: 

Fruitland, Menefee, and Crevasse Canyon Formation Coals in the San Juan Basin, and Moreno 

Hill Formation Coals in Salt Lake Field: New Mexico Bureau of Mines and Mineral Resources 

Bulletin 141, p.17–49.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Hunt, C.B., 1936, The Mount Taylor coal fi eld, in Sears, J.D., Hunt, C.B., and Dane, C.H., eds., Geology 

and Fuel Resources of the Southern Part of the San Juan Basin: U.S. Geological Survey Bulletin 

860-B, p. 31–80.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Pierce, W.H., and Shomaker, J.W., 1971, San Mateo Menefee area, in Shomaker, J.W., Beaumont, 

E.C., and Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in 

New Mexico and Colorado: New Mexico State Bureau of Mines and Mineral Resources Memoir 

25, p.64–69.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B67

Standing Rock Coal Field

Location

The Standing Rock coal fi eld is located in McKinley County, New Mexico, in the 

southern part of the San Juan Basin. The fi eld is arbitrarily separated from the San Mateo 

fi eld at T. 8 W.

Stratigraphy

Coal was studied on outcrop by Hunt (1936) and in the subsurface by Hoffman 

(1993).

Table. Stratigraphy—Standing Rock coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Menefee Formation 

 Cleary Coal Member coastal plain; coal ~290 

Point Lookout Sandstone nearshore marine ~80 

Coal Deposits

Coals in the Cleary Coal Member of the Menefee Formation are generally thin but 

can be as thick as 24 ft in one area of the fi eld near the Standing Rock Trading Post 

(Shomaker, 1971, fi g. 27).

Coal Quality

Coal in the fi eld is subbituminous A in rank, and averages about 13 percent ash and 

1.0 percent sulfur (Hoffman, 1996).

Table. Coal in Cleary Coal Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 13.32 1.06 9,429 

Standard deviation 3.35 0.38 552 

Number of analyses 27 27 27 
B68 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Demonstrated resources, estimated from limited data, total about 392 million short 

tons in areas with less than 200 ft of overburden (Hoffman, 1996).

Production History

Coal has been produced for domestic use only from small mine openings (Hoffman, 

1996).

References

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Hoffman, G.K., 1993, Description of coal-bearing sequences, in Hoffman, G.K., Campbell, F.W., and 

Beaumont, E.C., eds., Quality Assessment of Strippable Coals in Northwestern New Mexico: 

Fruitland, Menefee, and Crevasse Canyon Formation Coals in the San Juan Basin, and Moreno 

Hill Formation Coals in Salt Lake Field: New Mexico Bureau of Mines and Mineral Resources 

Bulletin 141, p.17–53.

Hunt, C.B., 1936, The Mount Taylor coal fi eld, in Sears, J.D., Hunt, C.B., and Dane, C.H., eds., Geology 

and Fuel Resources of the Southern Part of the San Juan Basin: U.S. Geological Survey Bulletin 

860-B, p. 31–80.

Shomaker, J.W., 1971, Standing Rock Cleary area, in Shomaker, J.W., Beaumont, E.C., and Kottlowski, 

F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico and 

Colorado: New Mexico State Bureau of Mines and Mineral Resources Memoir 25, p. 69–75.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B69

Star Lake Coal Field

Location

The Star Lake coal fi eld is located in McKinley, San Juan, and Sandoval Counties 

in northwestern New Mexico (Shomaker and Lease, 1971, fi g. 55). The fi eld is on the 

southern edge of the San Juan Basin and is defi ned by the limit of Fruitland Formation 

outcrops on the south, by the boundary between R. 8 W. and R. 9 W. to the west and by 

the thinning of the unit and change in trend near Cuba, N. Mex. to the east.

Stratigraphy

The area was studied in detail by Dane (1936). The Fruitland Formation, and coals 

within it, thin in the eastern part of the fi eld.

Table. Stratigraphy—Star Lake coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Kirtland Shale alluvial plain 200 

Fruitland Formation coastal plain; major coal 217 

Pictured Cliffs Sandstone nearshore marine 40-100 

Coal Deposits

Coals in the Fruitland are as thick as 15.9 ft but generally contain numerous thin 

partings (Shomaker and Lease, 1971). The coal thins toward the eastern part of the fi eld.

Coal Quality

The coals are subbituminous A to high-volatile bituminous C in rank, and contain 

15 to 20 percent ash and 0.4 to 0.7 percent sulfur (Shomaker and Lease, 1971). The 

following table showing averages for ash, sulfur, and heat content is from Hoffman 

(1996).

Table. Coal in Fruitland Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 22.42 0.55 8,636 

Standard deviation 4.43 0.12 702 

Number of analyses 52 52 52 
B70 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Demonstrated surface-minable coal resource estimates for the area are 946 million 

short tons in beds greater than 2.5 ft thick and with less than 200 ft of overburden 

(Hoffman, 1996).

Production History

Interest in leasing coal has been ongoing since the 1960’s, and several exploration 

projects have been conducted in the area (Nickelson, 1988). No active mines are currently 

in operation.

References

Dane, C.H., 1936, The La Ventana–Chacra Mesa coal fi eld, in Sears, J.D., Hunt, C.B., and Dane, C.H., 

eds., Geology and Fuel Resources of the Southern Part of the San Juan Basin: U.S. Geological 

Survey Bulletin 860-C, p 81–166.

Hoffman, G.K., 1996, Coal resources of New Mexico: New Mexico Bureau of Mines and Mineral 

Resources Resource Map 20, 22 p., 1 plate, scale 1:1,000,000.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Shomaker, J.W., and Lease, R.C., 1971, Star Lake Fruitland fi eld, in Shomaker, J.W., Beaumont, 

E.C., and Kottlowski, F.E., eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in 

New Mexico and Colorado: New Mexico Bureau of Mines and Mineral Resources Memoir 25, 

p. 117–123.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B71

Tierra Amarilla Coal Field

Location

The Tierra Amarilla is located on the east fl ank of the Chama Basin within Rio 

Arriba County, New Mexico.

Stratigraphy

The stratigraphy and thicknesses of units in the table below are from Landis and 

Dane (1969).

Table. Stratigraphy—Tierra Amarilla coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Lewis Shale marine 1,000 

Menefee Formation coastal plain; coal 99-120 

Point Lookout Sandstone shoreface 40-67 

Coal Deposits

Landis and Dane (1969) recognized nine separate, thin coal beds in the Menefee 

Formation. The thickest individual bed is 4.1 ft thick and it is located stratigraphically in 

the lower part of the formation (Landis and Dane, 1969, fi g. 3).

Coal Quality

The Menefee coals have an apparent rank of between subbituminous A and highvolatile C bituminous (Landis and Dane, 1969). Coal samples were collected from the 

tipple of the Dandee mine and analyzed by the U.S. Bureau of Mines; the results of the 

analyses are reported in the following table from Landis and Dane (1969).

Table. Coal in Menefee Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Range 7.7 1.0-1.1 9,640-10,110 

Number of analyses 1 2 2 
B72 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Not enough data are available to provide a meaningful estimate of the resources; 

however, most coal beds are less than 2.5 ft thick and will probably remain uneconomical 

for development (Nickelson, 1988).

Production History

Three small mines operated in the area between 1935 and 1955 (Nickelson, 1988)

References 

Landis, E.R., and Dane, C.H., 1969, The Tierra Amarilla coal fi eld, Rio Arriba County, New Mexico: 

New Mexico Bureau of Mines and Mineral Resources Circular 100, 14 p.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B73

Zuni Coal Field

Location

The Zuni coal fi eld in McKinley and Cibola Counties, in western New Mexico, is 

a continuation of the Gallup coal fi eld. The coal fi eld is entirely within the Zuni Indian 

Reservation and is part of the Zuni Basin, a northwest-trending asymmetric syncline 

(Anderson, 1987).

Stratigraphy

The stratigraphy was fi rst worked out in detail by Sears (1925), and was later 

placed into a regional context by Hook and others (1983). Geologic mapping and coal 

geology was refi ned by Anderson (1987) and Anderson and Stricker (1987). Approximate 

thicknesses of units are from Hook and others (1983, Pescado Creek section).

Table. Stratigraphy—Zuni coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Crevasse Canyon Formation 

 Dilco Coal Member coastal plain; coal 175 (part) 

Gallup Sandstone 

 Torrivio Member fluvial 125 

 Ramah unit coastal plain; minor coal 75 

 F sandstone nearshore marine 60 

Mancos Shale 

 Pescado Tongue marine 55 

Tres Hermanos Formation 

 Fite Ranch Member nearshore marine 40 

 Carthage Member coastal plain; coal 150 

 Atarque Sandstone 

 Member nearshore marine 50 

Coal Deposits

Coal is present within the Dilco Coal Member of the Crevasse Canyon Formation, 

the School mine coal group in the Gallup Sandstone, and in the Harper and Shoemaker 

Canyon coal zones in the Carthage Member of the Tres Hermanos Formation (Anderson 

and Stricker, 1987). The Harper coals in the Carthage are 3 to 4 ft thick, and the upper 

zone in the Gallup is as thick as 7 ft (Anderson and Stricker, 1987).

Coal Quality

The coal in the Zuni fi eld has an apparent rank of high-volatile C bituminous 

(Anderson, 1987). The sulfur content of the Gallup Ramah unit is between 0.6 and 1.5 

percent, and ash content is between 8.8 and 36.0 percent (Anderson and Stricker, 1987).

Table. Coal in Ramah unit. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

8.8-36.0 0.6-1.5 10,470-11,250 
B74 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Three areas in the middle of the fi eld are thought to have strippable resources 

totaling about 6 million short tons (Kottlowski, 1971). Anderson (1987) estimated coal 

resources in the Gallup Sandstone at about 49 million short tons in the southeastern part 

of the fi eld.

Production History

Three small mines operated in the coal fi eld between 1905 and 1958 (Nickelson, 

1988).

References

Anderson, O.J., 1987, Geology and coal resources of Atarque Lake 1:50,000 quadrangle, New 

Mexico: New Mexico Bureau of Mines and Mineral Resources Geologic Map 61.

Anderson, O.J., and Stricker, G.D, 1987, Stratigraphy and coal occurrences of the Tres Hermanos 

Formation and Gallup Sandstone (Upper Cretaceous), Zuni Basin, west-central New Mexico, 

in Roybal, G.H., Anderson, O.J., and Beaumont, E.C., eds., Coal Deposits and Facies Changes 

Along the Southwestern Margin of the Late Cretaceous Seaway, West-Central New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 121, p. 59–63.

Hook, S.B., Molenaar, C.M., and Cobban, W.A., 1983, Stratigraphy and revision of nomenclature of 

upper Cenomanian to Turonian (Upper Cretaceous) rocks of west-central New Mexico, in Hook, 

S.B., ed., Contribution to Mid-Cretaceous Paleontology and Stratigraphy of New Mexico—Part II: 

New Mexico Bureau of Mines and Mineral Resources Circular 185, p. 7–28.

Kottlowski, F.E., 1971, Zuni Mesaverde area, in Shomaker, J.W., Beaumont, E.C., and Kottlowski, F.E., 

eds., Strippable Low-Sulfur Coal Resources of the San Juan Basin in New Mexico and Colorado: 

New Mexico State Bureau of Mines and Mineral Resources Memoir 25, p. 75–89.

Nickelson, H.B., 1988, One hundred years of coal mining in the San Juan Basin, New Mexico: New 

Mexico Bureau of Mines and Mineral Resources Bulletin 111, 226 p.

Sears, J.D., 1925, Geology and coal resources of the Gallup-Zuni Basin, New Mexico: U.S. Geological 

Survey Bulletin 767, 53 p.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B75

Utah

Alton Coal Field

Location

The Alton coal fi eld is located in Kane and Garfi eld Counties in southern Utah 

and encompasses about 175 mi2

; about 28,000 acres were originally leased for coal. The 

fi eld lies adjacent to Bryce Canyon National Park, and the coal is likely present in the 

subsurface beneath the Park. The easternmost part of the fi eld is within the boundary of 

the Grand Staircase–Escalante National Monument.

Stratigraphy

The major coal-bearing unit in the Alton coal fi eld is the Cretaceous Dakota Sandstone. Thickness of Dakota Sandstone is from Kauffman and others (1987); thickness of 

the Tropic Shale is from Cashion (1961).

Table. Stratigraphy—Alton coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Tropic Shale marine 1,200 

Dakota Sandstone 

 upper member nearshore marine 75 

 middle member alluvial plain; major coal 150 

 lower member fluvial 0-150 

Coal Deposits

There are two major coal zones in the Dakota: the Smirl ( or upper coal zone), which 

has a maximum coal thickness of 18 ft in T. 39 S., R. 6 W. (Cashion, 1961, section 45); 

and the Bald Knoll (or lower coal zone), which has a maximum coal thickness 8.7 ft 

including three partings in T. 39 S., R. 6 W. (Cashion, 1961, section 44).

Coal Quality

Coal in the Alton fi eld has a range of apparent rank of from subbituminous C to highvolatile bituminous C (Doelling, 1972). The range of selected proximate/ultimate analyses 

of nine coal samples from the Smirl zone are compiled below from Affolter and Hatch 

(1980). Averages are from R.H. Affolter, (written comm., 1997).

Table. Coal in Dakota Sandstone. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 10.2 1.2 8,796 

Range 4.8-20.9 0.5-3.5 6,260-9,780 
B76 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Original coal reserves from the fi eld have been estimated by Cashion (1961) and 

by Doelling (1972). Doelling estimated 2.1 billion short tons of reserves, of which 200 

million short tons are under less than 200 ft of overburden and are considered strippable. 

Part of the fi eld (T. 40 S., Rs. 4.5–5 W.) was studied under the Energy Mineral Rehabilitation Inventory and Analysis project that provided data on soils, vegetation, hydrology, 

coal distribution, and reclamation potential of the area (Bureau of Land Management, 

1975). As part of that study, approximately a 30-mi2 area was determined to have about 

90 million short tons of coal in beds greater than 10 ft thick and with less than 200 ft of 

overburden (Bowers and others, 1976).

Production History

There is no active production in the Alton fi eld. Eight mines operated historically in 

the southwestern part of the fi eld with less than 50,000 short tons produced (Doelling, 

1972). Five leases from State and Federal Governments have been granted in the fi eld.

References

Affolter, R.H., and Hatch, J.R., 1980, Chemical analyses of coal from the Dakota and Straight Cliffs 

Formations, southwestern Utah region, Kane and Garfi eld Counties, Utah: U.S. Geological Survey 

Open-File Report 80-138, 32 p.

Bowers, W.E., Aigen, A.A., and Landis, E.R., 1976, Coal resources of the Alton, Utah, EMRIA site: U.S. 

Geological Survey Open-File Report 76-386, 32 p.

Bureau of Land Management, 1975, Alton coal fi eld, Kane County, Utah: Energy Mineral Rehabilitation Inventory Analysis, 130 p. 

Cashion, W.B., 1961, Geology and fuel resources of the Orderville-Glendale area, Kane County, Utah: 

U.S. Geological Survey Coal Investigations Map C-49.

Doelling, H.H., 1972, Alton coal fi eld, in Doelling, H.H., and Graham, R.L., eds., Southwestern Utah 

Coal Fields: Utah Geological and Mineralogical Survey Monograph No. 1, p. 1–66.

Kauffman, E.G., Sageman, B.B., Gustason, E.R., and Elder, W.P., 1987, High-resolution event stratigraphy, Greenhorn cyclothem (Cretaceous: Cenomanian-Turonian), Western Interior basin of 

Colorado and Utah: Boulder, Colo., Geological Society of America Guidebook, Rocky Mountain 

Section, 198 p.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B77

Book Cliffs Coal Field

Location

The Book Cliffs coal fi eld is located in Emery, Carbon, and Utah Counties in eastcentral Utah and lies on the northeast-dipping fl ank of the Uinta Basin. The coal fi eld 

was historically, and is presently, one of the most important coal fi elds in Utah. The 

fi eld extends for about 70 mi in length, extending from a few miles west of Price, 

Utah, southeastward to the canyon of the Green River. The area contains four mining 

districts—from west to east, the Castlegate, Soldier Canyon, Sunnyside, and Woodside 

districts (Doelling, 1972).

Stratigraphy

The coal-bearing unit in the Book Cliffs fi eld is the Blackhawk Formation. The 

stratigraphy and coal geology were fi rst studied in detail by Clark (1928). The Blackhawk 

is about 1,500 ft thick in the western part of the fi eld and thins to as little as 450 ft toward 

the southeastern part of the fi eld (Balsley, 1980; Young, 1955).

Table. Stratigraphy—Book Cliffs coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Castlegate Sandstone fluvial 150-500 

Blackhawk Formation coastal plain; major coal 450-1,150 

Star Point Sandstone nearshore marine 0-300 

Coal Deposits

The coal geology of the eastern part of the Book Cliffs was studied in detail by Clark 

(1928). A comprehensive summary of the fi eld was compiled by Doelling (1972) and is 

further updated by Tabet (in press). The main coal zones are, in ascending order, Spring 

Canyon (4–10 ft), Castlegate A, B, C, D (4–18 ft), Kennilworth (4–28 ft), Gilson (4–18 

ft), Rock Canyon (4–12 ft), and Sunnyside, (4–16 ft) (Tabet, in press).

Coal Quality

A summary of seven beds in the table below is based on more than 900 samples 

compiled from data of Tabet (in press). Details of the Spring Canyon (Subseam), Castlegate A and B, Kenilworth, Gilson, Rock Canyon, and Lower Sunnyside are available in 

Tabet (in press).

Table. Coal in Blackhawk Formation. 

[Values reported on an as-received basis]

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

5-8 0.38-0.98 12,512-12,910 
B78 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

Original in-place resources for the Book Cliffs coal fi eld are about 3.5 billion short 

tons for beds greater than 4 ft thick beneath less than 3,000 ft of overburden (Tabet, in 

press, modifi ed from Doelling, 1972, and Anderson, 1983).

Production History

The Book Cliffs coal fi eld has produced coal since the 1870’s and, as of 1997, about 

270 million short tons of coal were mined from the area (Jahanbani, 1996). More than 50 

major mines have operated in the Book Cliffs from 1896 to the present (Doelling, 1972). 

The Book Cliffs coal fi eld has produced about 2–3 million short tons of coal per year for 

the last 15 years (Jahanbani, 1996). Three major mines produced 3.15 million short tons 

in 1996. The opening of the Willow Creek mine will add about 2 million short tons of 

production to the Book Cliffs in the coming years (Jahanbani, 1996).

References

Anderson, P.B., 1983, Geologic map of the Pine Canyon quadrangle, Carbon County, Utah: Utah 

Geological and Mineralogical Survey Map 72, 14 p.

Balsley, J.K., 1980, Cretaceous wave-dominated delta systems: Book Cliffs, east central Utah: A Field 

Guide, Amoco Production Company, 163 p.

Clark, F.R., 1928, Economic geology of the Castlegate, Wellington, and Sunnyside quadrangles, 

Carbon County, Utah: U.S. Geological Survey Bulletin 793, 165 p.

Doelling, H.H., 1972, Book Cliffs coal fi eld, in Doelling, H.H., ed., Central Utah Coal Fields: Utah 

Geological and Mineralogical Survey Monograph Series No. 3, p. 245–415.

Jahanbani, F.R., 1996, 1995 Annual review and forecast of Utah coal, production and distribution: 

State of Utah Natural Resources, Offi ce of Energy and Resource Planning, 26 p.

Tabet, D.E, in press, Coal Resources: Carbon-Emery Counties Report.

Young, R.G., 1955, Sedimentary facies and intertonging in the Upper Cretaceous of the Book Cliffs, 

Utah-Colorado: Geological Society of America Bulletin, v. 66, p. 177–202.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B79

Emery Coal Field

Location

The Emery coal fi eld is located within Emery County in central Utah. The fi eld 

extends for about 35 mi in a northeast-southwest direction. The eastern edge of the fi eld 

is bounded by good exposures called the Coal Cliffs. The fi eld is bounded on the south 

by volcanic rocks on the Fish Lake Plateau, and is limited to the west by excessive depth 

beneath the Wasatch Plateau. The coal deposits extend into the subsurface to the north and 

the fi eld boundary is arbitrarily chosen near Price, Utah. We include the Ferron coal-bed 

gas play (fi g. 1) in this summary—(play 2052 Uinta Piceance–Emery of Rice, 1995).

Stratigraphy

Thicknesses of the Tununk and Ferron Sandstone Members of the Mancos Shale are 

from isopach maps from Ryer and McPhillips (1983) for the Emery coal fi eld and the 

Ferron play. Sequence stratigraphic studies of the unit have been completed by Gardner 

(1993).

Table. Stratigraphy—Emery coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mancos Shale 

 Blue Gate Member marine (part) 

 Ferron Sandstone 

 Member coastal plain/nearshore marine; coal 55-830 

 Tununk Member marine 300-790 

Coal Deposits

The coal was fi rst described by Lupton (1916) and named, in ascending order, the A, 

B, C, D, G, I, J, L, and M. Isopach maps of the A, C, G, J, and I are shown in Ryer (1981), 

who also provides an excellent summary of the associated depositional environments of 

the Ferron coal-bearing interval in the Emery fi eld. These isopachs show a pod shape for 

most of the Ferron coal deposits.

Coal Quality

The rank of the coal is high-volatile bituminous B, and mean values of ash and sulfur 

contents are summarized below (Tabet, in press). The data, based on about 75 samples, 

are from the A, C, G, and I beds.

Table. Coal in Ferron Sandstone Member. 

[Values reported on an as-received basis]

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

8.20-14.54 0.78-1.26 11,275-12,179 
B80 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Resources

The Ferron coals in the Emery coal fi eld proper are estimated to contain about 1.4 

billion short tons (Doelling, 1972, p. 437). An additional undetermined resource is present 

in the area around Price, Utah, where coal-bed methane is currently being produced in the 

Drunkard’s Wash fi eld (Gloyn and Sommer, 1993). The Drunkard’s Wash fi eld contains 

coal beds as much as 28 ft thick with overburden depths of between 100 and 2,500 ft 

(Bunnell and Hollberg, 1991).

Production History

As of 1996, cumulative production from the Emery fi eld was 270 million short tons; 

however, there has been no active mining since 1990 (Jahanbani, 1996).

References

Bunnell, M.D., and Hollberg, R.J., 1991, Coal beds of the Ferron Sandstone Member in northern 

Castle Valley, east-central Utah, in Chidsey, T.C., Jr., ed., Geology of East-Central Utah: Utah 

Geological Association Publication 19, p. 157–172.

Doelling, H.H., 1972, Emery coal fi eld, in Doelling, H.H., ed., Central Utah Coal Fields: Utah Geological 

and Mineralogical Survey Monograph Series No. 3, p. 417–496.

Gardner, M.H., 1993, Sequence stratigraphy and facies architecture of the Upper Cretaceous Ferron 

Sandstone Member of the Mancos Shale, east-central Utah: Golden, Colo., Colorado School of 

Mines, unpub. Ph.D. dissertation, 528 p.

Gloyn, R.W., and Sommer, S.N., 1993, Exploration for coalbed methane gains momentum in Uinta 

Basin: Oil and Gas Journal, May 31, p. 73–76.

Lupton, C.T., 1916, Geology and coal resources of Castle Valley in Carbon, Emery, and Sevier Counties, Utah: U.S. Geological Survey Bulletin 628, 88 p.

Jahanbani, F.R., 1996, 1995 Annual review and forecast of Utah coal, production and distribution: 

State of Utah Natural Resources, Offi ce of Energy and Resource Planning, 26 p.

Rice, D.D., 1996, Geologic framework and description of coalbed gas plays, in Gautier, D.L., Dolton, 

G.L., Takashashi, K.I., and Varnes, K.L. eds., 1995 National Assessment of United States Oil and 

Gas Resources—Results, Methodology, and Supporting Data: U.S. Geological Survey Digital Data 

Series DDS-30, Release 2.

Ryer, T.A., 1981, Deltaic coals of Ferron Sandstone Member of Mancos Shale: Predictive model for 

Cretaceous coal-bearing strata of Western Interior: American Association of Petroleum Geologists Bulletin, v. 65, p. 2323–2340.

Ryer, T.A., and McPhillips, M., 1983, Early Late Cretaceous paleogeography of east-central Utah, 

in Reynolds, M.W., and Dolly, E.D., eds., Mesozoic Paleogeography of the West-Central United 

States: Rocky Mountain Section of Society of Economic Paleontologists and Mineralogists Rocky 

Mountain Paleogeography Symposium 2, p. 253–272.

Tabet, D.E, in press, Coal Resources: Carbon-Emery Counties Report.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B81

Henry Mountains Coal Field

Location

The Henry Mountains coal fi eld is located in south-central Utah in parts of Emery, 

Garfi eld, and Wayne Counties. The fi eld is within a structural basin, and the coal is 

limited to an area of about 450 mi2. The basin is bounded on the west by the Waterpocket 

fold where the beds generally dip 20°–30°. The east side of the basin is bounded by 

numerous laccolithic igneous intrusions that locally alter the coal (Hunt and others, 1953).

Stratigraphy

Coal is present in three units, in ascending order, the Dakota Sandstone, Ferron 

Sandstone Member of the Mancos Shale, and Masuk Formation (Emery Sandstone 

Member of the Mancos Shale of Hunt and others, 1953; sometimes referred to as Muley 

Canyon Sandstone Member of Mancos Shale—see discussion of stratigraphy by Eaton, 

1990). Although the older formations have the greatest areal extent, the greatest resource 

and best quality coal is in the youngest coal-bearing unit—the Masuk Formation (Doelling, 1972). The stratigraphy and unit thickness are from Hunt and others (1953) and 

Eaton (1990).

Table. Stratigraphy—Henry Mountains coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Tarantula Mesa Sandstone continental 270-400 

Masuk Formation coastal plain; major coal 600-750 

Muley Canyon Sandstone nearshore marine 270 

Mancos Shale 

 Blue Gate Member marine 1,400 

 Ferron Sandstone 

 Member nearshore marine/coastal plain; coal 150-300 

 Tununk Member marine 525-650 

Dakota Sandstone alluvial to marginal marine; minor coal 1-75 

Coal Deposits

Coals in the Dakota Sandstone are thin and discontinuous. Coals in the Ferron are as 

much as 9 ft thick, but only over a 5-mi2 area in the north part of the Henry Mountains 

coal fi eld (Factory Butte area; Doelling and Smith, 1982). The thickest coal in the Masuk 

Formation is 13.4 ft, and the maximum cumulative thickness of coal is about 23 ft in three 

to four beds (Law, 1979, measured section 27; Law, 1980). The most up-to-date report on 

coal in the Henry Mountains is by Tabet (1999) and Tabet (chap. R, this CD-ROM).

Coal Quality

The Ferron coals have an apparent rank of high-volatile bituminous C, and the 

Masuk (Emery) coals have a range of apparent rank of subbituminous A to high-volatile 

bituminous C (Hatch and others, 1980; Doelling and Smith, 1982). Proximate/ultimate 

analyses for coal of the Henry Mountains are summarized in the tables below from 

Doelling (1972) for one sample in the Dakota and from Tabet (1999) for four samples in 

the Ferron and 37 samples in the Masuk (Muley Canyon).
B82 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Additional data on chemical analyses from the coal-bearing units are given by 

Hatch and others (1980), who reported proximate and ultimate analyses for 16 core and 

abandoned-mine samples in the central part of the Henry Mountains coal fi eld. For the 

Masuk Formation (Emery), ash content ranges from 7.1 to 27.3 percent and the sulfur 

content ranges from 0.4 to 1.0 percent.

Resources

The Ferron Sandstone Member and Masuk Formation have signifi cant coal resources 

in the area. For coal beds greater than 6 ft thick, the Ferron is reported to contain about 

219 million short tons of in-place resources; the Masuk (Muley Canyon) is estimated to 

have at least 1,388 million short tons of in-place resources (Tabet, 1999).

Production History

As of 1982, only about 59,000 short tons of coal were mined from the Henry 

Mountains Basin (Doelling and Smith, 1982). The majority of the production was from 

the Ferron in the far northern part of the fi eld (Factory Butte area).

References

Doelling, H.H., 1972, Henry Mountains coal fi eld, in Doelling, H.H., and Graham, R.L., eds., Eastern 

and Northern Utah Coal Fields: Utah Geological and Mineralogical Survey Monograph Series No. 

2, p. 97–190.

Doelling, H.H., and Smith, M.R., 1982, Overview of Utah coal fi elds, 1982, in Gurgel, K.D., ed., Proceedings, Fifth Symposium on the Geology of Rocky Mountain Coal 1982: Utah Geological and Mineral 

Survey Bulletin 118, p. 1–26.

Eaton, J.G., 1990, Stratigraphic revision of Campanian (Upper Cretaceous) rocks in the Henry Basin, 

Utah: Mountain Geologist, v. 27, p. 27–38.

Table. Coal in Masuk Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Mean 11.74 0.9 10,086 

Table. Coal in Ferron Sandstone Member. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Mean 14.5 2.5 11,038 

Table. Coal in Dakota Sandstone. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Mean 1.7 2.92 13,478 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B83

Hatch, J.R., Affolter, R.H., and Law, B.E., 1980, Chemical analyses of coal from Emery and Ferron 

Sandstone Members of Mancos Shale, Henry Mountains fi eld, Wayne and Garfi eld Counties, 

Utah, in Picard, M.D., ed., Henry Mountains Symposium: Utah Geological Association Publication 

8, p. 323–325.

Hunt, C.B., Averitt, P., and Miller, R.L., 1953, Geology and geography of the Henry Mountains region, 

Utah: U.S. Geological Survey Professional Paper 228, 234 p.

Law, B.E., 1979, Surface coal sections in the Emery coal zone, Henry Mountains coal fi eld, Utah: U.S. 

Geological Survey Miscellaneous Field Studies MF-1082, 2 sheets.

Law, B.E., 1980, Tectonic and sedimentological controls of the coal bed depositional patterns in 

Upper Cretaceous Emery Sandstone, Henry Mountains coal fi eld, Utah, in Picard, M.D., ed., Henry 

Mountains Symposium: Utah Geological Association Publication 8, p. 323–325.

Tabet, D.E., 1999, Coal resources of the Henry Mountains coalfi eld: Utah Geological Survey Open-File 

Report 362, 32 p.
B84 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Kaiparowits Plateau

Location

The Kaiparowits Plateau coal fi eld is located in Kane and Garfi eld Counties of 

south-central Utah. The margins of the fi eld are defi ned on the east by the Straight Cliffs 

Escarpment, on the west by the Kaibab monocline and Joes Valley anticline, on the 

north by the Aquarius Plateau, and on the south by the Gray Cliffs. The northern part 

of the fi eld is within the Dixie National Forest, and the southern part is in the Grand 

Staircase–Escalante National Monument.

Stratigraphy

The stratigraphy and thickness data are from Hettinger and others (chap. T, table 2, 

this CD-ROM), based on Sargent and Hansen (1982) and Peterson (1969a, 1969b).

Table. Stratigraphy—Kaiparowits coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Straight Cliffs Formation 

 Drip Tank Member fluvial 140-400 

 John Henry Member coastal plain/nearshore marine; major coal 600-1,500 

 Smoky Hollow 

 Member fluvial/coastal plain: minor coal 20-300 

 Tibbet Canyon 

 Member nearshore marine 60-185 

Tropic Shale marine 600-900 

Dakota Sandstone fluvial/nearshore marine; minor coal 15-250 

Coal Deposits

The main coal-bearing unit in the Kaiparowits Plateau fi eld is the John Henry 

Member of the Straight Cliffs Formation. Coal zones within the John Henry include, 

in ascending order, the Henderson (or lower), Christensen, Rees, and Alvey. The John 

Henry contains as many as 30 individual beds as thick as 59 ft (Hettinger and others, 

chap. T, this CD-ROM). Minor amounts of coal are also present in the Smoky Hollow 

Member of the Straight Cliffs Formation and the Dakota Sandstone, but the beds are 

thin and lenticular.

Coal Quality

The apparent rank of the John Henry coals changes systematically from subbituminous B in the northern part of the plateau to high-volatile bituminous B in the southern 

part of the Plateau (Kohler and others, 1997). The proximate/ultimate analysis of about 

100 samples from mines and outcrops provide the data for the table below, derived from 

Doelling and Graham (1972, p. 123–127).

Table. Coal in John Henry Member of the Straight Cliffs Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

5.0-6.6 0.6-2.1 9,890-12,270 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B85

Resources

Coal resources for the Kaiparowits equal about 60.5 billion short tons for beds 

greater than 1 ft thick beneath less than 600 ft of overburden (Hettinger and others, chap. 

T, table 6, this CD-ROM). About 30 billion short tons were calculated for areas where 

the overburden is less than 3,000 ft, the strata dip less than 12 degrees, and the beds are 

between 3.5 and 14 ft thick (beds thicker than 14 ft thick were calculated as 14 ft thick) 

(Hettinger and others, chap. T, this CD-ROM).

Production History

Between 1910 and 1970, less than 50,000 short tons of coal were produced from 

about 15 small mines (Hettinger and others, chap. T, his table 1, this CD-ROM).

References

Doelling, H.H., and Graham, R.L., 1972, The Kaiparowits coal fi eld, in Doelling, H.H., and Graham, 

R.L., eds., Southwestern Utah Coal Fields: Utah Geological and Mineralogical Survey Monograph 

No. 1, p. 67–249.

Kohler, J.F., Quick, J.C., and Tabet, D.E., 1997, Variation in the chemistry of Upper Cretaceous, 

Straight Cliffs Formation coals, in Hill, L.M., ed., Learning from the Land: Grand Staircase–

Escalante National Monument Science Symposium Proceedings, p. 307–318.

Peterson, F., 1969a, Cretaceous sedimentation, and tectonism of the southeastern Kaiparowits 

Plateau, Utah: U.S. Geological Survey Open-File Report 69-202, 259 p.

Peterson, F., 1969b, Four new members of the Upper Cretaceous Straight Cliffs Formation in the 

southeastern Kaiparowits Plateau region, Kane County, Utah: U.S. Geological Survey Bulletin 

1274-J, 28 p.

Sargent, K.A., and Hansen, D.E., 1982, Bedrock geologic map of the Kaiparowits coal-basin area, 

Utah: U.S. Geological Survey Miscellaneous Investigations Series Map I-1033-I, scale 1:125,000.
B86 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Kolob-Harmony Coal Fields

Location

The Kolob-Harmony coal fi elds are located in parts of Kane, Iron, and Washington 

Counties in southwestern Utah. The Kolob fi eld is the larger of the two fi elds, and is 

separated from the Harmony fi eld by the Hurricane fault, and from the Alton fi eld by 

the Sevier fault.

Stratigraphy

The coal is present in the Dakota Sandstone in the Kolob fi eld (called the Tropic 

Formation by Averitt, 1962) or in the Iron Springs Formation in isolated outcrops of 

the Harmony fi eld. The thickness of the Dakota is from Gustason (1989), Kauffman and 

others (1987) and Averitt (1962); the thickness of Tropic is from Cashion (1961) and 

Averitt (1962).

Table. Stratigraphy—Kolob-Harmony coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Tropic Shale marine 0-250 

Dakota Sandstone 

 upper member nearshore marine/coastal plain; coal 150 

 middle member alluvial plain; minor coal 1,025 

 lower member fluvial 50 

Coal Deposits

Coal in the lower member of the Dakota Sandstone is called the lower coal zone, and 

the coal in the upper member of the Dakota Sandstone is called the upper or Culver coal 

zone. The lower coal is as much as 4 ft thick, and the Culver zone averages about 5–6 ft 

thick but can be as thick as 10 ft (Averitt, 1962; Doelling and Smith, 1982).

Coal Quality

The coal in the Kolob-Harmony fi elds is subbituminous A to bituminous C in 

rank (Doelling 1972). Locally in the Harmony fi eld, some coal is metamorphosed by 

igneous intrusions to an apparent rank of semianthracite. Coal analyses for the Kolob and 

Harmony fi elds in the table below are from Doelling and Smith (1982).

Table. Coal in Dakota Sandstone—Kolob. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Range of mean 10.8-11.5 2.21-5.76 10,344-10,500 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B87

Resources

Doelling and Smith (1982) report about 2.0 billion short tons of coal in the Kolob 

fi eld in beds greater than 4.0 ft thick, most of which (about 95 percent) is in the upper 

zone. Insignifi cant resources are present in the Harmony fi eld (Doelling and Smith, 1982).

Production History

About 25 mines have operated in the area between 1852 and 1966, and, cumulatively, they have produced less than a million short tons of coal (Doelling, 1972).

References

Averitt, P., 1962, Geology and coal resources of the Cedar Mountain quadrangle, Iron County, Utah: 

U.S. Geological Survey Professional Paper 389, 72 p.

Cashion, W.B., 1961, Geology and fuels resources of the Orderville-Glendale area, Kane County, 

Utah: U.S. Geological Survey Coal Investigations Map C-49.

Doelling, H.H., 1972, Kolob-Harmony coal fi elds, in Doelling, H.H., and Graham, R.L., eds., Southwestern Utah Coal Fields: Utah Geological and Mineralogical Survey Monograph No. 1, p. 251–333.

Doelling, H.H., and Smith, M.R., 1982, Overview of Utah coal fi elds, 1982, in Gurgel, K.D., ed., Proceedings Fifth Symposium on the Geology of Rocky Mountain Coal 1982: Utah Geological and Mineral 

Survey Bulletin 118, p. 1–26. 

Gustason, E.R., 1989, Stratigraphy and sedimentology of the middle Cretaceous (Albian-Cenomanian) 

Dakota Formation, southwestern Utah: Boulder, Colo., University of Colorado Ph. D. dissertation, 

376 p.

Kauffman, E.G., Sageman, B.B., Gustason, E.R., and Elder, W.P., 1987, High-resolution event stratigraphy, Greenhorn cyclothem (Cretaceous: Cenomanian-Turonian), Western Interior basin of 

Colorado and Utah: Boulder, Colo., Geological Society of America Guidebook, Rocky Mountain 

Section, 198 p.

Table. Coal in Dakota Sandstone—Harmony. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Mean 26.6 3.31 9,100 
B88 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Salina Canyon Coal Field

Location

The Salina Canyon coal fi eld is a minor fi eld located within Sevier County, Utah, 

west of the Wasatch Plateau along Interstate 70. The fi eld is highly dissected by northsouth-trending normal faults, including the Musinia fault zone (Spieker and Baker, 1928).

Stratigraphy

The stratigraphy and coal geology were fi rst studied in detail by Spieker and Baker 

(1928). A compilation of the geology of the area is included in (Doelling 1972). Coals are 

present in the Castlegate Sandstone and Blackhawk Formation.

Table. Stratigraphy—Salina Canyon coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Castlegate Sandstone fluvial; minor coal 229 

Blackhawk Formation coastal plain; major coal 540 (part) 

Coal Deposits 

There are three coal beds within the Blackhawk Formation: the Wilson, Sevier, and 

Ivie beds. Most of the coal beds are about 2–3 ft thick; however, the Ivie bed is reported as 

between 6 and 10 ft thick on outcrop (Spieker and Baker, 1928). The Ivie bed was found 

to be 4.7–6.3 ft thick in the subsurface based on three drill holes, and between 4.7 and 7.5 

ft thick in the Sevier Valley Mine as reported in Doelling (1972, p. 39).

Coal Quality

Coal quality information in the table below is based on the range of 11 to 13 samples 

compiled from Doelling (1972, table 16).

Table. Coal in Blackhawk Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

4.2-13.2 0.32-0.6 9,690-12,080 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B89

Resources

Spieker and Baker (1928) estimated about 170 million short tons of coal for the 

Salina Canyon fi eld over an area of about 30 mi2. They estimated that the Ivie bed may 

contain as much as 140 million short tons in an aggregate area of about 20 mi2. Doelling 

(1972) reports a potential resource of about 69 million short tons for about 7,700 acres 

west of the Musinia fault.

Production History

Five small mines operated in the coal fi eld between 1910 and 1953, having produced 

about 430,000 tons of coal (Doelling, 1972).

References

Doelling, H.H., 1972, Sevier-Sanpete region, in Doelling, H.H., ed., Central Utah Coal Fields: SevierSanpete, Wasatch Plateau, Book Cliffs and Emery: Utah Geological and Mineralogical Survey 

Monograph No. 1, p. 1–57.

Spieker, E.M., and Baker, A.A., 1928, Salina Canyon district, Sevier County, Utah: U.S. Geological 

Survey Bulletin 796-C, p.125–170.
B90 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Sego Coal Field

Location

The Sego coal fi eld is situated in the eastern part of the Book Cliffs within Grand 

County in Utah. The fi eld is on the southern fl ank of the Uinta Basin, which has gentle 

dips to the north. The fi eld is about 6 mi in width and about 65 mi in length, covering 

an area of about 400 mi2

 (Doelling, 1972). The coal-bearing Neslen Formation extends 

across the Colorado State line, becoming the Mount Garfi eld Formation (see summary of 

Book Cliffs coal fi eld, Colorado).

Stratigraphy

The stratigraphy of the coal-bearing Neslen was fi rst worked out in detail by Fisher 

(1936) and later refi ned by Fisher and others (1960) and Kirschbaum and Hettinger 

(1998). Thickness of the formation is from Fisher (1936) and Kirschbaum and Hettinger 

(1998). The coal deposits present in the easternmost part of the fi eld were studied by 

Gualtieri (1991a, 1991b)

Table. Stratigraphy—Sego coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Castlegate Sandstone (part) 

 Bluecastle Tongue alluvial 0-150 

 Neslen Formation coastal plain; coal 250-410 

 Sego Sandstone tidal/nearshore marine 140-213 

Coal Deposits

The coal zones in the Neslen Formation were fi rst mapped and named by Fisher 

(1936) and include, in ascending order, the Palisade, Ballard, Chesterfi eld, and Carbonera. 

The most important bed is the Chesterfi eld coal, which has been extensively mined in the 

Sego Canyon area (Doelling, 1972; Willis, 1986). The Chesterfi eld attains a maximum 

thickness on outcrop of about 5 ft (Fisher, 1936, plates 13–15). Gaultieri (1991a, 1991b) 

noted in drill holes a maximum thickness of about 7 ft for the Chesterfi eld in the 

easternmost part of the fi eld.

Coal Quality

The coal is high-volatile B-C bituminous (Gualtieri, 1991a, 1991b). Ash, sulfur and 

Btu/lb data in the following table are from Doelling and Smith (1982).

Table. Coal in Neslen Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

4-19 0.37-1.0 9,000-12,000 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B91

Resources

Doelling (1972) reported 293.5 millions of short tons of coal in the Neslen in beds 

greater than 4 ft thick. Gualtieri (1991b) reported about 180 million short tons of coal in 

the combined lower (Palisade) Ballard, Carbonera, and local beds.

Production History

Eight mines and several prospects operated in the Sego coal fi eld between 1898 and 

1953 and produced a total of 2.65 million short tons of coal (Doelling, 1972).

References

Doelling, H.H., 1972, Sego coal fi eld, in Doelling, H.H., and Graham, R.L., eds., Eastern and Northern 

Utah Coal Fields: Utah Geological and Mineralogical Survey Monograph Series No. 2, p. 191–267.

Doelling, H.H., and Smith, M.R., 1982, Overview of Utah coal fi elds, 1982, in Gurgel, K.D., ed., Proceedings, Fifth Symposium on the Geology of Rocky Mountain Coal 1982: Utah Geological and Mineral 

Survey Bulletin 118, p. 1–26.

Fisher, D.J., 1936, The Book Cliffs coal fi eld in Emery and Grand Counties, Utah: U.S. Geological 

Survey Bulletin 852, 104 p.

Fisher, D.J, Erdmann, C.E., and Reeside J.B., Jr., 1960, Cretaceous and Tertiary Formations of the 

Book Cliffs Carbon, Emery and Grand Counties, Utah, and Garfi eld and Mesa Counties, Colorado: 

U.S. Geological Survey Professional Paper 332, 80 p.

Gualtieri, J.L., 1991a, Map and cross sections of coal zones in the Upper Cretaceous Neslen Formation, north-central part of the Westwater 30’x60’ quadrangle, Grand and Uintah Counties, Utah: 

U.S. Geological Survey Coal Investigations Map C-133.

Gualtieri, J.L., 1991b, Map and cross sections of coal zones in the Upper Cretaceous Neslen and 

Mount Garfi eld Formations, northeastern part of the Westwater 30’x60’ quadrangle and adjacent 

area, Garfi eld County, Colorado, and Grand and Uintah Counties, Utah: U.S. Geological Survey 

Coal Investigations Map C-134.

Kirschbaum, M.A., and Hettinger, R.D., 1998, Stratigraphy and depositional environments of the 

late Campanian coal-bearing Neslen/Mount Garfi eld Formations eastern Book Cliffs, Utah and 

Colorado: U.S. Geological Survey Open-File Report 98-43.

Willis, G.C., 1986, Geology, depositional environment, and coal resources of the Sego Canyon 71/2-

minute quadrangle, near Green River, east central Utah: Brigham Young University Geology 

Studies v. 33, part 1, p. 175–208.
B92 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Tabby Mountain Coal Field 

Location

The Tabby Mountain coal fi eld is located on the northwestern fl ank of the Uinta 

Basin and extends for about 35 mi within Wasatch and Duchesne Counties, Utah (Doelling and Smith, 1982). Strata dip from 24 to 75 degrees, and the western margin of the 

fi eld is highly deformed from eastward-directed thrusting (Doelling and Smith, 1982). 

Most of the coal is owned by the Uinta and Ouray Indian Tribes (Doelling and Smith, 

1982).

Stratigraphy

Lupton (1912) completed the fi rst fairly detailed study of the stratigraphy and geology of the coal-bearing units. Lupton’s study and later stratigraphic and geologic studies 

were compiled by Doelling (1972). The revised stratigraphy and thickness of the Frontier 

Formation is from Molenaar and Wilson (1990). Thicknesses of the upper shale member 

of the Mancos Shale and the Mesaverde Formation are from Lupton (1912).

Table. Stratigraphy—Tabby Mountain coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mesaverde Formation coastal plain/nearshore marine; coal 3,300 

Mancos Group 

 upper shale member marine shale 1,450 

 Frontier Formation coastal plain/nearshore marine; coal 760 

 unnamed shale unit marine shale 170 

 Mowry Shale marine shale 200 

Coal Deposits

Coal as thick as 10 ft is present in the Frontier Formation (Doelling and Smith, 

1982). As many as 21 beds of coal are present in the Mesaverde Formation and they are as 

much as 28 ft thick (Lupton, 1912). The main bed is named the Fraughton.

Coal Quality

The coal in the Frontier and Mesaverde is subbituminous C to lignite A in apparent 

rank. Ash and sulfur content in the following table are from (Doelling and Smith, 1982). 

Calorifi c values, based on 27 analyses indicate an apparent rank of lignite (Affolter, chap. 

G, this CD-ROM); Doelling and Smith (1982) reported values of 8,000 to 10,000 Btu/lb.

Table. Coal in Frontier and Mesaverde Formations. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

6-10 0.7-1.0 3,674-7,784 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B93

Resources

The Tabby Mountain fi eld is estimated to have about 1.9 billion short tons of coal 

in beds greater than 14 inches thick and under less than 3,000 ft of overburden (Lupton, 

1912). Of this amount, Doelling (1972) estimated that about 231 million tons are in beds 

greater than 4 ft thick and under less than 3,000 ft of overburden.

Production History

Four small mines and a few prospects operated in the Tabby Mountain fi eld from the 

early 1900’s until about 1949 (Doelling, 1972).

References

Doelling, H.H., 1972, Tabby Mountain coal fi eld, in Doelling, H.H., and Graham, R.L., eds., Eastern 

and Northern Utah Coal Fields: Utah Geological and Mineralogical Survey Monograph Series No. 

2, p. 281–321.

Doelling, H.H., and Smith, M.R., 1982, Overview of Utah coal fi elds, 1982, in Gurgel, K.D., ed., Proceedings Fifth Symposium on the Geology of Rocky Mountain Coal 1982: Utah Geological and Mineral 

Survey Bulletin 118, p. 1–26.

Lupton, C.T., 1912, The Blacktail (Tabby) Mountain coal fi eld, Wasatch County, Utah, in Campbell, 

M.R., ed., Contribution to Economic Geology 1910: U.S. Geological Survey Bulletin 471, p. 595–628.

Molenaar, C.M., and Wilson, B.W., 1990, The Frontier Formation and associated rocks of northeastern Utah and northwestern Colorado: U.S. Geological Survey Bulletin 1787, 21 p.
B94 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Vernal Coal Field

Location

The Vernal fi eld is located on the northeast margin of the Uinta Basin in Uintah 

County, Utah.

Stratigraphy

A brief summary of the coal deposits of the fi eld was completed by Gale (1910) 

and Lupton (1912). Kinney (1955) studied the stratigraphy and mapped the geology of 

part of the fi eld and worked on the Frontier Formation coals. A regional stratigraphic 

study was completed by Molenaar and Wilson (1990). The most comprehensive report 

on the coal geology is by Doelling and Graham (1972). Thicknesses of units are from 

Kinney (1955).

Table. Stratigraphy—Vernal coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Mesaverde Formation nearshore marine; coastal plain; coal 1,100 

Mancos Group 

 upper shale member marine 4,900 

 Frontier Formation nearshore marine; coastal plain; coal 140-270 

 Mowry Shale marine 30-120 

Coal Deposits

Coal beds in this fi eld contain numerous partings and dip steeply. The coal beds are 

generally thin, although Frontier coals are as thick as 8.1 ft and Mesaverde Formation 

coals can be as thick as 7.0 ft (Doelling and Graham 1972).

Coal Quality

Both the Frontier and Mesaverde coals have an apparent rank of high-volatile C 

bituminous. Averages for ash, sulfur, and heat contents are given in the table below 

(Doelling and Smith, 1982).

Table. Coal in Mesaverde Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

17.5 0.8 8,750 

Table. Coal in Frontier Formation. 

[Values reported on an as-received basis] 

Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

12.5 1.6 11,510 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B95

Resources

Inferred resources with as much as 3,000 ft of overburden equal about 164 million 

short tons in the Frontier and about 13 million short tons in the Mesaverde (Doelling and 

Graham, 1972, p. 26–27).

Production History

About 52 mines or prospects were opened in the area between the 1870’s and 

1955, producing a total of about 250,000 short tons of coal (Kinney, 1955; Doelling and 

Graham, 1972; Doelling and Smith, 1982).

References

Doelling, H.H., and Graham, R.L., 1972, Vernal coal fi eld, in Doelling, H.H., and Graham, R.L., eds., 

Eastern and Northern Utah Coal Fields: Utah Geological and Mineralogical Survey Monograph 

Series No. 2, p. 1–95.

Doelling, H.H., and Smith, M.R., 1982, Overview of Utah coal fi elds, 1982, in Gurgel, K.D., ed., Proceedings Fifth Symposium on the Geology of Rocky Mountain Coal 1982: Utah Geological and Mineral 

Survey Bulletin 118, p. 1–26.

Gale, H.S., 1910, Coal fi elds of northwestern Colorado and northeastern Utah: U.S. Geological Survey 

Bulletin 415, 265 p.

Kinney, D.M., 1955, Geology of the Uinta River–Brush Creek area, Duchesne and Uintah Counties, 

Utah: U.S. Geological Survey Bulletin 1007, 185 p.

Lupton, C.T., 1912, The Deep Creek district of the Vernal coal fi eld, Uinta County, Utah, in Campbell, 

M.R., ed., Contribution to Economic Geology 1910: U.S. Geological Survey Bulletin 471, p. 579–594.

Molenaar, C.M., and Wilson, B.W., 1990, The Frontier Formation and associated rocks of northeastern Utah and northwestern Colorado: U.S. Geological Survey Bulletin 1787, 21 p.
B96 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Wales Coal Field

Location

The Wales coal fi eld is a minor fi eld located in Sanpete County, Utah. The fi eld is 

just west of the Colorado Plateau proper and is on the east side of the Gunnison Plateau 

(San Pitch Mountains) within the Basin and Range Province.

Stratigraphy

A reconnaissance study of the coal was completed by Richardson (1906), and the 

earliest detailed study of the coal was by Clark (1914). Coal in the Wales coal fi eld 

is present within the Cretaceous-Tertiary North Horn Formation. The coal is in the 

Cretaceous part of the unit (Lawton and others, 1993). The stratigraphy and thickness is 

from Lawton and others (1993).

Table. Stratigraphy—Wales coal field. 

Stratigraphic unit Depositional environment Thickness (ft) 

North Horn Formation 

 coal-bearing unit alluvial/lacustrine 131-374 

Coal Deposits 

Numerous thin beds as much as 6.6 ft thick (with partings) are present in the coal 

unit (Doelling, 1972; Lawton and others, 1993).

Coal Quality

Coal chemistry data in the following table are from a compilation by Doelling 

(1972).

Table. Coal in North Horn Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Average 14.8 4.3 10,119 

Range 4.0-29.2 2.88-6.79 6,554-11,857 

Number of analyses 13 8 6 
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B97

Resources

The fi eld contains about 12 million short tons of coal (Doelling, 1972).

Production History

The Wales coal fi eld dates back to 1855. Several small mines operated until 1955, 

producing a total of 175,000 short tons of coal (Doelling, 1972).

References

Clark, F.R., 1914, Coal near Wales, Sanpete County, Utah, in Campbell, M.R., ed., Contributions to 

Economic Geology 1912: U.S. Geological Survey Bulletin 541, p. 478–489.

Doelling, H.H., 1972, Sevier-Sanpete region, in Doelling, H.H., ed., Central Utah Coal Fields: Utah 

Geological and Mineralogical Survey Monograph No. 3, p. 1–57.

Lawton, T.F., Talling, P.J., Hobbs, R.S., Trexler, Jr., J.H., and Weiss, M.P., 1993, Structure and Stratigraphy of Upper Cretaceous and Paleogene Strata (North Horn Formation), Eastern San Pitch 

Mountains, Utah—Sedimentation at the Front of the Sevier Orogenic Belt: U.S. Geological Survey 

Bulletin 1787-II, 33 p.

Richardson, G.B., 1906, Coal in Sanpete County, Utah, in Emmons, S.F., and Eckel, E.C., eds., Contributions to Economic Geology 1905: U.S. Geological Survey Bulletin 285, p. 280–284.
B98 Geology and Resource Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah

Wasatch Plateau Coal Field

Location

The Wasatch Plateau is the most important coal fi eld in Utah. The fi eld is located in 

the center of the State within Carbon, Emery, Sanpete, and Sevier Counties and partially 

within Utah and Wasatch Counties (Doelling and Smith, 1982). The coal fi eld is about 

90 mi long and about 10–20 mi wide. The fi eld is cut by a series of generally north-southtrending normal faults that partition the fi eld into seven distinct coal areas, as defi ned 

by Doelling (1972b, his fi g. 18, p. 127). Three smaller fi elds are present west of the 

main Wasatch Plateau coal fi eld: the Mount Pleasant, Salina Canyon, and Sterling fi elds 

(Doelling, 1972a). The Salina Canyon fi eld is included separately in this report.

Stratigraphy

The fi rst comprehensive study of the stratigraphy and coal geology of the Blackhawk 

Formation was conducted by Spieker (1931). Thicknesses for the members of the Mancos 

Shale are from the Three States National Gas Co., Joe’s Valley No. 3 well, as reported 

in Roberts and Kirschbaum (1995, p. 90). Thicknesses of upper units are from Spieker 

(1931).

Table. Stratigraphy—Wasatch Plateau coal field. 

Stratigraphic units Depositional environment Thickness (ft) 

Castlegate Sandstone fluvial 500 

Blackhawk Formation coastal plain; major coal 700-1,000 

Star Point Sandstone nearshore marine 222-500 

Mancos Shale 

 Masuk Member marine 1,590 

 Emery Sandstone 

 Member coastal plain; major coal 1,200 

 Blue Gate Member marine 2,160 

Coal Deposits

Coal is present in two units: the Blackhawk Formation and the Emery Sandstone 

Member of the Mancos Shale. Coal in the Emery is little known because it is present only 

in the subsurface and relatively few drill holes penetrate the unit. The Emery contains at 

least six coal beds in the Joe’s Valley No. 3 well that are as much as 11 ft thick.

The Blackhawk Formation contains the most important coal-bearing unit and contains more than 20 individual beds that are greater than 4 ft thick (Tabet, in press). The 

main beds are the Accord Lakes, Axel Anderson, Blind Canyon (Lower O’Connor), Wattis 

(Upper O’Connor), Cottonwood, and Castlegate A (Bob Wright). Many of these beds 

were originally named the Hiawatha bed by Spieker (1931) who did not fully recognize 

the complex nature of the coal over the 9-mi length of the fi eld.

Coal Quality

The coal in the Blackhawk has an apparent rank of bituminous B and C (Tabet, 

in press). A summary of selected mean proximate/ultimate values based on about 750 

analyses from the Blind Canyon, Castlegate A, Hiawatha, and Upper Hiawatha beds 

compiled from Tabet (in press) are given in the table below.
A Summary of the Coal Deposits in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah B99

Resources

Spieker (1931) estimated 13 billion short tons of coal in beds greater than 14 inches 

thick for the Wasatch Plateau, and he estimated 7.8 billion short tons for beds greater 

than 30 inches thick. Original minable reserves were estimated at about 6.4 billion short 

tons by Doelling (1972b).

Production History

Production from numerous mines between 1870 and 1996 has totaled about 386 

million short tons (Jahanbani, 1996) or 5 percent of the resource originally estimated by 

Spieker (1931) for beds greater than 30 inches thick. As of 1996, there were eight major 

underground mines operating in the Wasatch Plateau that produced about 24 million short 

tons of coal (Jahanbani, 1996). Four of the mines are longwall operations: Deer Creek, 

SUFCO, Skyline, and Trail Mountain, all of which are producing more than 3.5 million 

short tons a year as of 1996 (Fiscor, 1998; G. Sullivan, written commun., 1997—compiled 

from Mine Safety and Health Administration data).

References

Doelling, H.H., 1972a, Sevier-Sanpete region, in Doelling, H.H., ed., Central Utah Coal Fields: SevierSanpete, Wasatch Plateau, Book Cliffs and Emery: Utah Geological and Mineralogical Survey 

Monograph Series No. 3, p. 1–57.

Doelling, H.H., 1972b, Wasatch Plateau coal fi eld, in Doelling, H.H., ed., Central Utah Coal Fields: Utah 

Geological and Mineralogical Survey Monograph Series No. 3, p. 58–243.

Doelling, H.H., and Smith, M.R., 1982, Overview of Utah coal fi elds, 1982, in Gurgel, K.D., ed., Proceedings Fifth Symposium on the Geology of Rocky Mountain Coal 1982: Utah Geological and Mineral 

Survey Bulletin 118, p. 1–26.

Fiscor, S., 1998, U.S. longwalls thrive: Coal Age, Feb., p. 22–27.

Jahanbani, F.R., 1996, 1995 Annual review and forecast of Utah coal, production and distribution: 

State of Utah Natural Resources, Offi ce of Energy and Resource Planning, 26 p.

Roberts, L.N.R., and Kirschbaum, M.A., 1995, Paleogeography of the Late Cretaceous of the Western 

Interior of middle North America—Coal distribution and sediment Accumulation: U.S. Geological 

Survey Professional Paper 1561, 115 p.

Spieker, E.M., 1931, The Wasatch Plateau coal fi eld, Utah: U.S. Geological 

Survey Bulletin 819, 210 p.

Tabet, D.E, in press, Coal Resources: Carbon-Emery Counties Report.

Table. Coal in Blackhawk Formation. 

[Values reported on an as-received basis] 

 Ash content 

(percent) 

Sulfur content 

(percent) 

Heating value 

(Btu/lb) 

Mean Range 6.00-8.99 0.52-0.63 11,503-12,844 

National Coal

Resource

Assessment

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