Chapter R

Coal Resources of the 

Henry Mountains Coal Field, Utah

By David E. Tabet1

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 R 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

 Utah Geological Survey, Salt Lake City, Utah

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

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

Abstract........................................................................................................................................................R1

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

Location and Setting ........................................................................................................................... 1

Previous Work ...................................................................................................................................... 3

Methodology......................................................................................................................................... 7

Acknowledgments........................................................................................................................................ 7

Upper Cretaceous Stratigraphy ................................................................................................................. 7

Dakota Sandstone ............................................................................................................................... 7

Mancos Shale ...................................................................................................................................... 7

Tununk Member .......................................................................................................................... 8

Ferron Sandstone Member ....................................................................................................... 8

Blue Gate Member ..................................................................................................................... 8

Muley Canyon Sandstone Member ......................................................................................... 8

Masuk Member........................................................................................................................... 9

Tarantula Mesa Sandstone ................................................................................................................ 9

Younger Beds on Tarantula Mesa..................................................................................................... 9

Coal Geology................................................................................................................................................ 10

Thickness and Geometry of Ferron Coal........................................................................................ 10

Depth to Ferron Coal Zone ............................................................................................................... 10

Chemistry of Ferron Coal .................................................................................................................. 10

Coal Resources of the Ferron Sandstone Member...................................................................... 13

Thickness and Geometry of Muley Canyon Coal.......................................................................... 14

Depth to Muley Canyon Coal Zone ................................................................................................. 14

Chemistry of Muley Canyon Coal .................................................................................................... 14

Coal Resources of the Muley Canyon Sandstone Member........................................................ 22

Coal Development Potential............................................................................................................. 22

References Cited ........................................................................................................................................ 24

Figures

 1. Map showing location of Henry Mountains coal field .........................................................R2

 2. Photograph looking northeast across Henry Mountains coal field ..................................... 3

 3. Roads and major physiographic features in the vicinity of 

Henry Mountains coal field......................................................................................................... 4

 4. Map showing land ownership of Henry Mountains coal field.............................................. 5

 5. Chart showing evolution of Upper Cretaceous stratigraphic nomenclature of 

Henry Mountains Basin............................................................................................................... 6

 6. Isopach map of Ferron coal zone ............................................................................................ 11
 7. Overburden map of Ferron coal zone...................................................................................... 12

 8. Isopach map of Muley Canyon coal zone .............................................................................. 16

 9. Overburden map of Muley Canyon coal zone........................................................................ 17

 10. Map showing ash content of coal in Muley Canyon coal zone ......................................... 18

 11. Map showing sulfur content of coal in Muley Canyon coal zone ...................................... 19

 12. Map showing heat content of coal in Muley Canyon coal zone ........................................ 20

Tables

 1. Proximate analyses of Ferron coal samples........................................................................R10

 2. Total Ferron coal zone resources by thickness and county................................................ 13

 3. Total Ferron coal zone resources by thickness and depth of cover .................................. 13

 4. Total Ferron coal zone resources by thickness and township tier..................................... 13

 5. Proximate analyses of Muley Canyon coal samples............................................................ 15

 6. Major oxide composition of ash from 13 Muley Canyon coal samples from 

the Henry Mountains coal field................................................................................................ 21

 7. Ash type, fouling, and slagging evaluation of the oxide composition of 

Muley Canyon coal ash ............................................................................................................. 21

 8. Total Muley Canyon coal zone resources by thickness and depth of cover .................... 22

 9. Total Muley Canyon coal zone resources by thickness and county.................................. 23

 10. Total Muley Canyon coal zone resources by thickness and township tier....................... 23
Abstract

A reappraisal of the coal resources within the Ferron 

Sandstone Member and the Muley Canyon Sandstone Member 

of the Upper Cretaceous Mancos Shale in the Henry Mountains coal fi eld was made using recently obtained company 

drill-hole data in conjunction with older published drill-hole 

and measured-section data. Coal thickness and overburden 

thickness maps were prepared at a scale of 1:100,000 for 

both members. Coal-quality information was compiled and 

summarized in tabular form. The coals of the Henry Mountains 

coal fi eld are subbituminous A to high-volatile bituminous C 

in rank. The coals of the Muley Canyon have the best quality, 

with generally lower ash and sulfur content.

The in-place coal resources of both the Ferron and Muley 

Canyon Sandstone Members were calculated for 4-ft thickness 

intervals ranging from 2 to 6 ft, 6 to 10 ft, and greater than 10 

ft. The coal resources were also separated into overburden categories: 0 to 100 ft, 100 to 1,000 ft, and 1,000 to 2,000 ft. No 

coal resources in the Ferron or Muley Canyon Members are 

deeper than 2,000 ft. The coal resources were also subdivided 

by township tier and county. The majority of the coal resources 

for both units occurs in Garfi eld County, Utah. The Muley 

Canyon coal zone contains resources that are the thickest and 

of the best quality, and they comprise about 69 percent of the 

2.2 billion short tons of coal resources in the Henry Mountains 

coal fi eld.

Introduction

Location and Setting

The principal Cretaceous coal-bearing strata of the Henry 

Mountains coal fi eld cover parts of central Wayne and Garfi eld 

Counties, Utah (fi g. 1). Cretaceous strata are preserved in 

a structural basin, the Henry Mountains syncline, that is 

bounded on the west by the monocline of the Waterpocket 

fold, and on the east by the Monument upwarp. This northsouth-elongated basin extends about 50 mi along its axis and 

is 2 to 18 mi wide.

Elevations in the area of the Henry Mountains coal fi eld 

range from about 4,600 ft at the far northern end of the fi eld 

to more than 11,000 ft at Mt. Ellen in the central Henry 

Mountains. The topography varies from steep, rugged terrain 

in the Henry Mountains in the east, to a series of dissected 

mesas and buttes in the central part of the coal fi eld, and to 

cuestas and hogback ridges along the western margin of the 

coal fi eld (fi g. 2).

The Henry Mountains coal fi eld is in a remote area of 

Utah with few paved roads and no railroads. State Highway 

24 crosses the northern part of the coal fi eld and is the only 

paved road in the area. State Routes 95 and 276 (fi g. 3), which 

parallel the east margin of the coal fi eld, are 10 mi to the east. 

Access to most parts of the coal fi eld is limited to dirt roads. 

The nearest rail line is the Union Pacifi c line at Green River, 

Utah, about 60 mi to the north.

The remote Henry Mountains coal fi eld is an area of 

scenic beauty. The striking Waterpocket fold to the west has 

been set aside, in part, as the Capitol Reef National Park; to 

the south and southeast are parts of the Glen Canyon National 

Recreation Area. The majority of the coal-bearing lands (fi g. 

4) are administered by the U.S. Bureau of Land Management 

(BLM). The remote, relatively roadless nature of the Henry 

Mountains coal fi eld area led the BLM in 1990 to delineate 

three proposed Wilderness Areas covering parts of the coal 

fi eld. However, BLM’s proposals, which involved portions 

of the Mt. Ellen–Blue Hills, Mt. Pennell, and Mt. Hillers 

Wilderness Study Areas (WSA’s) would not, for the most part, 

constrain potential development of the coal resources. Only 

a few sections of land in the central narrows portion of the 

Mt. Ellen–Blue Hills WSA under Oak Creek Bench and a 

few sections on the western edge of the Mt. Pennell WSA 

along Bullfrog Creek overlie potentially minable coal deposits. 

However, the BLM (1999) has since conducted a reinventory 

of Utah lands for wilderness that has substantially increased 

the areas in the Henry Mountains coal fi eld being considered 

to have wilderness potential.

Minor coal occurs in the Dakota Sandstone, and minable 

quantities occur in the Ferron Sandatone and Muley Canyon 

Sandstone Members of the Mancos Shale (fi g. 5). The coalbearing Dakota Sandstone is thin and discontinuous, does 

not contain minable amounts of coal, and thus is considered 

to be an insignifi cant resource. The coals of the Ferron are 

R1

Coal Resources of the 

Henry Mountains Coal Field, Utah

By David E. Tabet
10 0 10 20 30 40 50 kilometers

10 0 10 20 30 40 miles

STATE OF UTAH

Henry

Mountains

Coal Field

DAVIS

WEBER

MORGAN

WASATCH

UTAH

SUMMIT

DUCHESNE

CARBON

BOX ELDER

TOOELE

JUAB

MILLARD

SALT

LAKE

EMERY

SANPETE

SEVIER

PIUTE

BEAVER

IRON GARFIELD

WAYNE

GRAND

UINTAH

SAN JUAN

WASHINGTON KANE

DAGGETT

CACHE

Great RICH

 Salt

 Lake

Utah

Lake

Sevier

Lake

Lake

Powell

River

Green

Colorado

River

San

Juan

River

Bear

Lake

Delta

Fillmore

Richfield

Salina

Manti

Ephraim

Castle Dale

Green River

Moab

La Sal

Junction

Monticello

Hanksville

Junction

Loa

Beaver

Milford

Parowan

Cedar City

St. George Washington

Panguitch

Kanab

Blanding

Mt.

Pleasant

Nephi

Tintic

Price

Duchesne

Manila

Park City

Coalville

Sandy

American

 Fork

Orem

Provo

Heber

 City

Tooele

Bountiful

Farmington

SALT

LAKE

CITY

Morgan

Randolph

Brigham

City

Ogden

Logan

Wendover

Vernal

36

89

40

191

30

16

15

15

84 80

84

80

15

15

80

6

191

191

6

191

10

89

89

50

24

50

6

50

6

40

15

15

70

237

70

70

6

191

89

130 666

89

15

15

Figure 1. Map showing location of Henry Mountains coal fi eld.

R2 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
locally thick, but also discontinuous, and have limited minable 

resources. Muley Canyon coals are the thickest, most continuous, and have the greatest amount of potentially minable 

resources (Doelling, 1972).

Coal in the Henry Mountains coal fi eld has been mined 

in the past on a limited scale from both the Ferron and Muley 

Canyon Sandstone Members. This coal was used locally to 

supply ranchers and residents of nearby towns (Doelling, 

1972).

Ferron coal, fi rst developed at the south end of the coal 

fi eld at the Stanton mine in section 36, T. 34 S., R. 10 E., was 

mined intermittently between 1888 and 1900 to supply gold 

dredges on the Colorado River to the south (Doelling, 1972). 

Small-scale mining of Ferron coal took place on a longer term 

basis at the far northern end of the fi eld near Factory Butte. 

Mining in this area began in 1908 and continued to produce 

coal for local use through the 1950’s. Renewed mining for 

electric power generation was attempted in the late 1970’s by 

the Atlas–Dirty Devil Mining Company, who opened a surface 

mine in June 1978, trucked the coal to Green River, Utah, 

and sent test shipments by rail to the power plant at Moapa, 

Nev. (Uresk, 1979). Problems with coal quality prevented this 

operation from achieving full production. 

The Muley Canyon coals were fi rst developed around 

1914 by tunneling into outcrops at the northern extent of 

this stratigraphic unit. W.D. Hendrickson started several small 

mines along Sweetwater Creek in section 30, T. 31 S., R. 9 

E. and Dugout Creek in section 7, T. 31 S., R. 9 E. to supply 

coal for local use (Hunt and others, 1953). Hunt and others 

(1953) reported that this coal was also later used to fuel a 

rig drilling two test wells in the Green River Desert. The last 

known activity at these mines was in the 1940’s (Doelling, 

1972).

Exploration on Federal and State lands over most of the 

Muley Canyon coal area was carried out by AMAX Coal Company, Cayman Corporation, Consolidation Coal Company, 

Gulf Mineral Resources Company, and the Federal Government in the mid-1970’s. Primary interest at the time was evaluating surface-minable coal deposits, but environmental concerns and limitations eventually caused all prospecting areas 

to be dropped. The availability of the exploration data from 

the combined efforts of all the parties active in the 1970’s 

has allowed the delineation of large amounts of deep Muley 

Canyon coal resources that could be mined with less surface 

disturbance than the originally anticipated surface mines.

Previous Work

Early reconnaissance surveys included the fi rst descriptions of the geology and coal deposits of the Henry Mountains 

region (Gilbert, 1877). The fi rst detailed study of the coal 

Figure 2. Photograph looking northeast across Henry Mountains coal fi eld showing steeply dipping Jurassic strata 

along the Waterpocket fold in the foreground, relatively fl at-lying mesas of Upper Cretaceous strata in the basin center, 

and intrusive-cored Henry Mountains on the east side of the coal fi eld along the southern horizon. Photo by Mark A. 

Kirschbaum, U.S. Geological Survey.

Coal Resources of the Henry Mountains Coal Field, Utah R3
276

24

95

95

Ferron

 coal zone

 outcrop

T26S

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S

T36S

Henry

Mountains

Monument upwarp

Swap

Mesa

Cave

Flat

Tarantula

Mesa

Wildcat

Mesa

H

e

nr y

Mountains

Waterp

ocket Fold

24

Muley Creek

R7E R8E R9E R10E R11E R12E

0 1 2 3 4 5 Miles

Utah

Figure 3. Roads and major physiographic features in the vicinity of the Henry Mountains coal fi eld.

R4 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
Figure 4. Map showing land ownership of Henry Mountains coal fi eld.

Utah

N

LEGEND

Federal coal and surface

State coal and surface

State coal, private surface

Federal coal, private surface

Private coal and surface

Ferron coal zone outcrop

T26S

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S

T36S

R7E R8E R9E R10E R11E R12E

0 1 2 3 4 5 Miles

Coal Resources of the Henry Mountains Coal Field, Utah R5
deposits of the Henry Mountains coal fi eld was conducted 

from 1935 to 1939 by the U.S. Geological Survey (USGS) 

(Hunt and others, 1953). Interest in the coal deposits waned 

until the early 1970’s when expanding fuel needs for electric 

generation sparked interest in domestic coal deposits. Doelling 

(1972) provided a detailed evaluation of the coal fi eld 

resources as part of his comprehensive study of the coal deposits of Utah. New information prompted Doelling (1975) and 

Doelling and Smith (1982) to revise earlier coal resource estimates and to provide more details on the surface-minable 

resources of the fi eld. McKell and others (1978) summarized 

the baseline data on the coal deposits and rehabilitation potential of coal lands in the coal fi eld for the BLM. Law (1977, 

1979a, 1979b, 1980) reported on the results of USGS drilling 

and fi eld work in the coal zone of the Emery Sandstone 

Member of the Mancos Shale (herein called the Muley Canyon 

Sandstone Member), and he concluded that tectonic and sedimentological controls caused the thickest coals in this unit to 

be deposited along the synclinal axis of the Henry Mountains 

Basin. Hatch and others (1979) presented coal-quality data for 

the Ferron and Emery Sandstone Members.

Peterson and others (1975, 1980) reevaluated the stratigraphy and regional relations of the Cretaceous System in the 

Henry Mountains region and found that the Emery of the 

Henry Mountains did not correlate with the type section in the 

Wasatch Plateau area; consequently, they recommended not 

using the term in the Henry Mountains region. Examination of 

the Ferron exposures in two parts of the coal fi eld led Uresk 

(1979) and Hill (1982) to conclude that the Ferron was deposited by a generally eastward prograding fl uvial-dominated deltaic complex. Smith (1983), Morton (1984, 1986), and Whitlock (1984) studied the geology and coal resources of three 

Masuk Sandstone Mesaverde Formation Tarantula Mesa

Sandstone

Tarantula Mesa

Sandstone

Masuk Shale

Masuk Formation

Masuk

Member

Masuk

Member

Blue Gate Sandstone Emery Sandstone

Member Muley Canyon

Sandstone Member

Muley Canyon

Sandstone

coal-bearing

Blue Gate Shale Blue Gate

Member

Blue Gate

Member

Blue Gate

Member

Tununk Sandstone Ferron Sandstone

Member

Ferron Sandstone

Member

Ferron Sandstone

Member

Tununk

Member

Tununk

Member

Tununk

Member Tununk Shale

Dakota Sandstone Dakota Sandstone Dakota Sandstone Dakota Sandstone

M

a

n

c

o

s

S

h

a

l

e

M

a

n

c

o

s

S

h

a

l

e

M

a

n

c

o

s

S

h

a

l

e

Gilbert (1872) Spieker and Reeside (1926)

THIS STUDY

Smith (1983)

PROPOSED

Eaton (1990)

Figure 5. Chart showing evolution of Upper Cretaceous stratigraphic nomenclature of Henry Mountains Basin.

R6 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
7.5-minute quadrangles in Garfi eld County. Following the suggestion of Peterson and others (1975,1980), Smith (1983) proposed changing the name of the Emery to the Muley Canyon 

Sandstone Member of the Mancos Shale and designated a 

type section in the southwest quarter of section 16, T. 33 S., 

R. 9 E., at the head of Muley Creek canyon. Eaton (1990) 

proposed revising the stratigraphy of the Campanian portion of 

the Upper Cretaceous section in the Henry Mountains Basin. 

He recommended (1) elevating the Muley Canyon to formational rank, as the Muley Canyon Sandstone, but restricting 

its usage to the lower cliff-forming marine sandstone portion 

of the unit; (2) renaming the Masuk Member of the Mancos 

Shale as the Masuk Formation because its predominant lithology is not shale and it is coastal plain in origin; (3) including 

the underlying coal-bearing portion of the Muley Canyon (formerly Emery) with his Masuk Formation because they are both 

coastal plain in origin; and (4) following Smith’s (1983) suggestion to rename the Mesaverde Formation of previous workers as the Tarantula Mesa Sandstone. Eaton’s (1990) nomenclature revisions would make the newly defi ned Muley Canyon 

Sandstone, Masuk Formation, and Tarantula Mesa Sandstone 

correlative, respectively, with to the Star Point Sandstone, 

Blackhawk Formation, and Castlegate Sandstone of the 

Wasatch Plateau area to the north of the Henry Mountains 

Basin.

As part of an updated coal resource assessment, a simplifi ed geologic map was compiled by Tabet (1999) for the Henry 

Mountains coal fi eld from parts of four regional maps by 

various workers. The geology of the western part the Henry 

Mountains coal fi eld was taken from a geologic map of Capitol 

Reef National Park by Billingsley and others (1987). The geology of the eastern part of the coal fi eld was taken from two 

geologic maps of Wilderness Study Areas (Larson and others, 

1985; Patterson and others, 1985). The geology of a small, 

northern part of the Henry Mountains Basin was modifi ed 

from Thompson (1967).

Methodology

This study builds on the work of previous investigators 

and includes new data from outcrop studies carried out by 

the Utah Geological Survey (UGS) during the late 1980’s 

as well as recently released coal company drilling and coalquality data. The coal outcrops, as mapped by the UGS on 

1:24,000-scale (7.5 minute) quadrangles, were digitized and 

then recompiled at a 1:100,000 scale. Coal-thickness measurements from outcrops were plotted on the maps only when they 

appeared to fully represent the complete coal section for each 

coal zone. Published and newly released coal exploration drilling data were plotted with the outcrop data to produce fi eldwide total coal-zone-thickness and depth-to-coal maps for the 

Ferron and Muley Canyon coal zones. These two coal zones 

are defi ned as the upper coal-bearing parts of the Ferron and 

Muley Canyon Sandstone Members, which average 110–120 

ft in thickness. Finally, coal resources were calculated using 

the demonstrated, inferred, and hypothetical data-spacing reliability categories developed by the USGS (Wood and others, 

1983). Demonstrated resources lie within 0.75 mi from a 

thickness-measurement point, inferred resources are between 

0.75 and 3 mi from a thickness-measurement point, and hypothetical resources lie more than 3 mi from a thickness-measurement point. The resources were also classifi ed using the 

following depth categories: less than 100 ft, 100 to 1,000 ft, 

and 1,000 to 2,000 ft. No coal resources in the Ferron and 

Muley Canyon are known to lie at depths below 2,000 ft.

Acknowledgments

Funding for this project was provided to the Utah Geological Survey by the USGS under cooperative agreements 

1408-0001-A-0164 and 1434-92-A-0954. Drilling data used 

in the study were kindly provided by AMAX Coal West, Incorporated (now RAG International Mining), the Pittsburg and 

Midway Coal Company, and Consolidation Coal Company. 

The author wishes to thank Russell Dubiel, Ed Johnson, and 

Tom Judkins of the U.S. Geological Survey for their helpful 

reviews of this paper. Finally, the author wishes to thank 

Brigitte Hucka, Robert Gloyn, Alex Keith, Steven Sommer, 

Sharon Wakefi eld, and various former UGS personnel who 

helped compile data for this study.

Upper Cretaceous Stratigraphy

Dakota Sandstone

The Upper Cretaceous Dakota Sandstone (fi g. 5) is the 

basal Upper Cretaceous unit, and it lies unconformably on 

older rocks (Peterson and others, 1980). It consists of a lower 

continental part of conglomeratic sandstone interbedded with 

carbonaceous mudstone and local thin beds of coal, and an 

upper marine part of fossiliferous, thin-bedded sandstone. 

Hunt and others (1953) reported a maximum Dakota thickness 

of 92 ft. Peterson and others (1980) report an average thickness 

of 35 ft. The formation is thickest in the southwestern part of 

the Henry Mountains coal fi eld and is thin and locally missing 

in the northern part. Coal beds in the Dakota are discontinuous 

and rarely exceed 2 ft thick. Because of the thin nature of this 

unit, and its minor coal resources, Tabet (1999) combined it 

with the overlying Tununk Member of the Mancos Shale on 

his geologic map of the area. 

Mancos Shale

The nomenclature of the Upper Cretaceous Mancos Shale 

in the Henry Mountains Basin is problematic, and numerous 

revisions have been suggested (see Previous Work section). 

Coal Resources of the Henry Mountains Coal Field, Utah R7
The presently available maps of the area depict the Mancos 

Shale as composed of fi ve members. In ascending order they 

are the Tununk, Ferron Sandstone, Blue Gate, Muley Canyon 

Sandstone, and Masuk Members (Smith, 1983) (see fi g. 5). 

Descriptions of these units are taken primarily from regional 

work of Peterson and others (1980), who consider each of 

these units “a distinct, mappable entity that probably should be 

considered a separate formation.”

Tununk Member

The Tununk Member conformably overlies the Dakota 

Sandstone and has a measured thickness from outcrop and 

drill holes ranging from 532 to 717 ft. The Tununk generally 

thickens toward the north. Lithologically, this unit is composed 

primarily of gray bentonitic, calcareous shale, but near the 

base and top it is yellowish-gray to greenish-gray mudstone, 

siltstone, and very fi ne grained sandstone.

Ferron Sandstone Member

This unit was fi rst named the Tununk Sandstone (Gilbert, 

1877), but was subsequently correlated by Spieker and Reeside 

(1926) with the type Ferron Member in the Castle Valley 

area, about 35 mi to the north of the Henry Mountains coal 

fi eld. It conformably overlies the Tununk and is comprised 

of 205–395 ft of interbedded sandstone, shale, mudstone, and 

coal. Peterson and others (1980) have recommended dividing 

the Ferron into lower and upper parts based on distinctive 

lithologies and depositional environments. 

According to Peterson and others (1980), the lower part 

of the Ferron consists of thin-bedded sandstone and shale at 

the base that grade upward to thick, cliff-forming sandstone 

at the top. This part of the Ferron averages 197 ft thick and 

ranges from 130 to 305 ft thick. The very fi ne to mediumgrained sandstones of the lower part grade from laminated and 

ripple cross-laminated at the base to trough cross-stratifi ed in 

the middle, and to low-angle cross-stratifi ed at the top. This 

vertical sequence of beds is interpreted as being deposited 

in a regressive coastal barrier-island environment (Peterson 

and others, 1980). They infer a northwest-trending shoreline 

during deposition of the lower Ferron based on sedimentary 

structure and sand-body-geometry orientations in this unit. The 

lower part of the Ferron interfi ngers with the Tununk and rises 

stratigraphically to the northeast.

The upper part of the Ferron is described by Peterson and 

others (1980) as a 15- to 205-ft-thick (average 110 ft) unit 

of interbedded lenticular sandstone, carbonaceous mudstone, 

and coal. The sandstones are lenticular, channel-shaped bodies 

that are generally less than 40 ft thick. Sedimentary structures 

indicate a southeasterly paleofl ow in the southwestern part of 

the basin (Hill, 1982), whereas those in the northeastern part 

of the basin have a northeasterly paleofl ow (Uresk, 1979). 

These channel sandstones are characterized by unidirectional 

cross-stratifi cation, fi ning-upward cycles, and lateral interfi ngering with mudstones. The interbedded carbonaceous mudstones occur in a variety of gray, brown, and black tones. 

As many as fi ve coal beds, some of minable thickness, can 

be found in the upper part of the Ferron. The depositional 

environment of the upper part was a system of meandering distributary channels and associated overbank fl ood-plain deposits (Peterson and others, 1980).

Blue Gate Member

The Blue Gate Member unconformably overlies the 

Ferron. The name Blue Gate Shale was fi rst proposed by 

Gilbert (1877) as a formation, but was reduced to a member 

of the Mancos Shale by Hunt and Miller (1946) and Hunt and 

others (1953). Although lithologically similar to the Tununk, 

the Blue Gate is much thicker, averaging 1,280 ft (Peterson 

and others, 1980). Range in thickness is 1,093 to 1,500 ft, and 

the member thickens northward. The upper 250-ft transition 

zone with the overlying Muley Canyon Member consists of 

interbedded yellowish- or greenish-gray mudstone, siltstone, 

and very fi ne grained sandstone.

Muley Canyon Sandstone Member

Sandstones overlying the Blue Gate were fi rst named 

the Blue Gate Sandstone by Gilbert (1877). Confusion over 

whether these strata correlated with the Ferron, Emery, or 

Mesaverde of the Wasatch Plateau caused Spieker and Reeside 

(1926) to erroneously name them Emery in the Henry Mountains region. Based on further work, Peterson and others 

(1980) determined that the proper correlation was with the 

Mesaverde Formation and suggested dropping the name 

Emery in the Henry Mountains region. Peterson and others 

(1980) subdivided the 298- to 446-ft-thick Muley Canyon 

strata into a lower and upper part. The lower, predominantly 

sandstone part forms prominent cliffs or cuestas, whereas the 

upper interbedded shale and sandstone unit forms a series 

of short slopes and small ledges. Subsequently, Smith (1983) 

proposed the name Muley Canyon Sandstone Member of the 

Mancos Shale for the strata between the Blue Gate and Masuk 

Members of the Mancos Shale. 

Eaton (1990) recommended removing the Muley Canyon 

as a member of the Mancos and elevating it to formational 

status. He also restricted the term Muley Canyon Sandstone to 

the lower cliff-forming marine part of the originally defi ned 

unit. Eaton’s proposal for future mapping in the area has 

much merit because it matches the scheme used for the 

type Mesaverde section of southwestern Colorado, where the 

distinct marine and nonmarine lithostratigraphic units have 

been separated as mappable units. The currently available geologic maps of the Henry Mountains coal fi eld area predate 

Eaton’s ideas, and these do not refl ect his stratigraphic scheme. 

Because the scope of the present study did not include remapR8 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
ping of the Cretaceous coal-bearing and associated units, this 

report follows the terminology of Smith (1983) because it 

can easily be applied to the mapping of earlier workers. The 

name Muley Canyon Sandstone Member of the Mancos Shale 

is used herein to avoid confusion with the Emery Sandstone 

Member elsewhere, and the Muley Canyon here includes the 

upper coal-bearing strata as mapped by previous workers.

The lower part of the Muley Canyon is a massive sandstone ranging in thickness from 131 to 307 ft and consists 

of very fi ne to medium-grained sandstone that is laminated 

to thin-bedded or cross-stratifi ed. The top of this lower part 

is commonly a clean, white, low-angle, cross-laminated sandstone (a “white cap”). Locally, in the vicinity of Wildcat Mesa, 

tidal channel sandstones scoured into the top of the lower 

part of the Muley Canyon have been identifi ed (Law, 1980). 

This unit was deposited in a regressive nearshore and shoreline 

marine environment.

The upper part of the Muley Canyon Sandstone Member 

is more heterogeneous lithologically than the lower part and 

consists of lenticular sandstones and interbedded carbonaceous 

mudstone and coal. This part ranges in thickness from 92 to 

209 ft and contains three to ten coal beds in an interval as 

much as 120 ft thick. This coal zone contains the thickest and 

most persistent coal beds in the Henry Mountains coal fi eld. 

The upper part of the Muley Canyon was deposited in fl uvial 

and tidal coastal-plain environments (Law, 1980). 

Masuk Member

The Masuk Member conformably overlies the Muley 

Canyon Sandstone Member. Peterson and others (1980) report 

that the gradational transition between the two members has 

made it diffi cult to pick a consistent marker horizon for the 

contact. Most workers have tried to pick some continuous 

sandstone above the coals to be the uppermost unit of the 

Muley Canyon, but most of the sandstones above the coals 

are discontinuous fl uvial channel deposits that do not create a 

persistent, easily mappable contact. To alleviate the problem, 

Eaton (1990) recommended that the coal-bearing portion of 

the Muley Canyon be included with the nonmarine Masuk and 

that the name Muley Canyon be restricted to the lower cliffforming marine portion of that unit. However, the geologic 

maps of the area (Billingsley and others, 1987; Larson and 

others, 1985; Patterson and others, 1985; Thompson, 1967) 

predate this recommendation.

The 600-plus feet of Masuk strata (Peterson and 

others, 1980) consists of two-thirds light-green mudstone 

with thin discontinuous lenses of carbonaceous mudstone or 

gray limestone, and one-third thin-bedded, ripple- or crosslaminated sandstone. The sandstones in the Masuk tend to 

have scoured bases and consist of fi ning-upward cycles. These 

mudstones and sandstones are typical of well-drained, fl oodplain and meandering-stream deposits. Fossils recovered from 

the Masuk support the interpretation of a freshwater, continental environment (Peterson and others, 1980). 

Tarantula Mesa Sandstone

Gilbert (1877) originally named the sandstones above 

his Masuk Shale the Masuk Sandstone. Subsequent workers 

(Spieker and Reeside, 1925; Hunt and Miller, 1946) assigned 

the sandstones to the Mesaverde Formation. The term 

Mesaverde was considered inappropriate by Peterson and 

others (1980), and they enclosed the term in quotes. Smith 

(1983) renamed the mesa-capping sandstones the Tarantula 

Mesa Sandstone, and Eaton (1990) also adopted this terminology.

The Tarantula Mesa Sandstone has a gradational contact 

with the underlying Masuk Member of the Mancos Shale. It 

is a gray or brown cliff-forming sandstone that is preserved 

only in the central portions of the Henry Mountains Basin 

on the top of Tarantula Mesa and on a few isolated surrounding mesas. Only a few sections of these strata have 

been measured with thicknesses ranging from 300 to 400 ft 

(Peterson and others, 1980). The Tarantula Mesa Sandstone is 

composed of seemingly continuous sandstones formed from 

laterally migrated, discrete channel bodies. According to Peterson and others (1980), these continuous-appearing sandstones 

contain very light gray or brown, fi ne-grained sandstone with 

local pebbles of chert, quartzite, and petrifi ed wood. The 

individual sandstone beds have tabular-planar to scoured contacts and exhibit cross-stratifi cation and fi ning-upward cycles. 

Cross-laminae in the lower part indicate transport to the southeast. A few thin lenses of gray mudstone are interbedded with 

the sandstones in the lower part of the formation. 

The upper part of the Tarantula Mesa Sandstone is more 

conglomeratic and exhibits less planar bedding surfaces and 

more scouring between beds. Higher depositional energy is 

also indicated by the lack of interbedded mudstone in the 

upper half, and cross lamination in this part of the unit indicates an east-northeast transport direction. The lithology and 

sedimentary structures of the Tarantula Mesa Sandstone point 

to a highly meandering or braided fl uvial environment of deposition (Peterson and others, 1980).

Younger Beds on Tarantula Mesa

Erosional remnants of younger Cretaceous strata are 

locally preserved on the top of Tarantula Mesa. Fossils reported 

by Eaton (1990) indicate a Campanian age. Only 36 to 100 ft of 

these beds are preserved, with the thickest deposits located on 

the western part of the mesa (Peterson and others, 1980). These 

strata are not well exposed because they are commonly capped 

by a veneer of Quaternary gravel and wind-blown sand. Where 

exposed, they consist of 75 percent yellowish- to greenish-gray 

mudstone with several carbonaceous lenses containing fossil 

plant fragments and 25 percent light- to dark-brown, very fi ne to 

fi ne-grained sandstone. The sandstones commonly have scoured 

bases and internally are planar bedded to cross-stratifi ed. This 

unit is interpreted to have been deposited in a fl ood-plain 

environment (Peterson and others, 1980).

Coal Resources of the Henry Mountains Coal Field, Utah R9
Coal Geology

Thickness and Geometry of Ferron Coal

The coals in the Ferron Sandstone Member of the Mancos 

Shale occur in the upper 110 ft of the nonmarine part of 

the unit. The coal beds are generally in a 50-ft-thick zone 

immediately above the lower marine part of the Ferron. The 

coal interval contains one to fi ve beds that have an aggregate 

thickness of coal as much as 16.5 ft. Individual coal beds 

seldom exceed 4 ft in thickness and commonly average 1–3 

ft thick.

The areal distribution of coal is patchy, with isolated eastwest-elongated pods present at scattered locations across the 

Henry Mountains Basin (fi g. 6). The pods are approximately 1–5 

mi wide and from 3 to 10 mi long. Although the coal-thickness 

data come primarily from the margins of the coal fi eld, it appears 

that the coal is best developed in three widely separated areas in 

the northern, central, and southern parts of the fi eld. The coal in 

the central area is more speculative than the other two because it 

relies heavily on data from only one deep oil and gas well.

Because the depositional environment for the Ferron in 

the Henry Mountains Basin has been interpreted as a fl uvialdeltaic complex (Uresk, 1979; Hill, 1982), the east-westelongate coal pods might refl ect interfl uvial swamps formed 

on eastward-prograding fl uvial-delta lobes that formed in the 

northern, central, and southern parts of the basin. However, 

the original distribution of coal in the upper part of the Ferron 

might have been altered by the erosional nature of the upper 

Ferron contact with the overlying Blue Gate Member, which 

resulted in a variable thickness of the coal-bearing unit. 

Depth to Ferron Coal Zone

The coal in the Ferron Sandstone Member generally 

occurs in the upper part, but in many places throughout the 

fi eld there is no coal. Therefore, it was easier to map the 

top of the Ferron to approximate the depth to the coal zone 

throughout the fi eld (fi g. 7). The top of the Ferron is exposed 

around the margins of the Henry Mountains Basin, and it 

reaches a maximum depth of slightly more than 2,000 ft in an 

area several square miles in extent that lies beneath the highest 

portions of Tarantula Mesa in the central part of the basin. 

Thus, all the Ferron coal deposits of the Henry Mountains coal 

fi eld that are thick enough to mine occur at potentially minable 

depths.

Chemistry of Ferron Coal

Only four coal-sample analyses from the Ferron have 

been published for the Henry Mountains coal fi eld (Doelling, 

1972; Hatch and others, 1979). These coals have an apparent 

rank of high-volatile C bituminous. The four samples come 

from the northern (3 samples) and southern (1 sample) edges 

of the fi eld. The mean analytical values indicate high ash (14.5 

percent) and sulfur (2.5 percent) contents. Table 1 gives the 

proximate analyses of the four coal samples.

Table 1. Proximate analyses of Ferron coal samples (as-received basis). 

 Cadastral Moisture Volatile matter Fixed carbon Ash Sulfur Btu per 

 location (percent) (percent) (percent) (percent) (percent) pound 

 02-27S-09E 8.3 34.1 43.8 13.8 1.6 10,650 

 11-27S-09E 4.9 33.5 48.7 12.9 2.6 10,920 

 11-27S-09E 5.5 33.6 44.9 16.0 2.5 10,840 

 36-34S-10E 4.6 38.1 42.2 15.1 3.2 11,743 

Mean 5.8 34.8 44.9 14.5 2.5 11,038 

Minimum 4.6 33.5 42.2 12.9 1.6 10,650 

Maximum 8.3 38.1 48.7 16.0 3.2 11,743 

Standard deviation 1.7 2.2 2.8 1.4 0.7 483 

R10 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
LEGEND

Coal isopach interval >10ft

Coal isopach interval 8-10ft

Coal isopach interval 6-8ft

Coal isopach interval 4-6ft

Coal isopach interval 2-4ft

Coal isopach interval 0-2ft

Ferron coal zone outcrop

0 1 2 3 4 5 Miles

Utah

N

T26S

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S

T36S

R7E R8E R9E R10E R11E R12E

Figure 6. Isopach map of Ferron coal zone.

Coal Resources of the Henry Mountains Coal Field, Utah R11
LEGEND

Overburden thickness > 2000 ft

Overburden thickness 1000-2000 ft

Overburden thickness 100-1000 ft

Overburden thickness 0-100 ft

Ferron coal zone outcrop

0 1 2 3 4 5 Miles

Utah

N

T26S

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S

T36S

R7E R8E R9E R10E R11E R12E

Figure 7. Overburden map of Ferron coal zone.

R12 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
Coal Resources of the 

Ferron Sandstone Member

The Ferron contains an estimated 683.5 million short tons 

of in-place coal resources, of which about three-quarters lie 

in Garfi eld County. Because of limited exploration data, only 

27 percent, or 187.3 million short tons, of the total resources 

falls in the demonstrated resource category (occurring within 

0.75 mi of a thickness-measurement point). The bulk of the 

coal resource, 67 percent, fall in the inferred resource category 

(occurring at least 0.75 to 3 mi from a thickness-measurement 

point). Only a few percent of the resources lie more than 3 

mi from a thickness-measurement point, or in the hypothetical 

category.

Overburden measurements show that 11 percent of the 

Table 2. Total Ferron coal zone resources by thickness and county. 

[All coal beds greater than or equal to 1 ft thick; figures in millions of short tons. DEM, demonstrated; INF, inferred; 

HYP, hypothetical] 

 2–6 ft thick 6–10 ft thick 10+ ft thick 

County DEM INF HYP DEM INF HYP DEM INF HYP 

Wayne 65.1 71.2 0.0 12.0 8.8 0.0 8.6 0.0 0.0 

Garfield 74.8 224.6 28.8 19.1 153.0 9.8 7.7 0.0 0.0 

TOTAL 139.9 295.8 28.8 31.1 161.8 9.8 16.3 0.0 0.0 

Table 3. Total Ferron coal zone resources by thickness and depth of cover. 

[All coal beds greater than or equal to 1 ft thick; figures in millions of short tons. DEM, demonstrated; INF, inferred; 

HYP, hypothetical] 

 2–6 ft thick 6–10 ft thick 10+ ft thick 

Depth (ft) DEM INF HYP DEM INF HYP DEM INF HYP 

0–100 54.2 5.1 0.0 6.7 2.2 0.0 6.9 0.0 0.0 

100-1,000 81.3 187.4 12.8 20.0 84.4 0.0 5.5 0.0 0.0 

1,000-2,000 4.3 103.3 16.0 4.5 75.3 9.8 4.0 0.0 0.0 

TOTAL 139.9 295.8 28.8 31.1 161.8 9.8 16.3 0.0 0.0 

Table 4. Total Ferron coal zone resources by thickness and township tier. 

[All coal beds greater than or equal to 1 ft thick; figures in millions of short tons. DEM, demonstrated; INF, inferred; 

HYP, hypothetical] 

 2–6 ft thick 6–10 ft thick 10+ ft thick 

Tier DEM INF HYP DEM INF HYP DEM INF HYP 

T. 27 S. 13.3 4.4 0.0 7.6 0.0 0.0 8.6 0.0 0.0 

T. 28 S. 19.8 28.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

T. 29 S. 13.2 3.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

T. 30 S. 18.8 35.0 0.0 4.4 8.8 0.0 0.0 0.0 0.0 

T. 31 S. 13.8 102.4 15.4 12.4 149.1 9.8 7.7 0.0 0.0 

T. 32 S. 11.2 44.8 13.5 0.0 0.0 0.0 0.0 0.0 0.0 

T. 33 S. 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 

T. 34 S. 49.8 77.3 0.0 6.7 3.9 0.0 0.0 0.0 0.0 

TOTAL 139.9 295.8 28.8 31.1 161.8 9.8 16.3 0.0 0.0 

Ferron resources, or 75.1 million short tons, lie at depths of 

100 ft or less, and that nearly all of the remainder is less 

than 2,000 ft deep (fi g. 7). As mentioned above, the total coal 

thickness in the Ferron is generally thin, and this is refl ected 

by the fact that 68 percent of the resources falls in the 2- to 

6-ft-thick resource category. Less than one-third of the coal 

resources have an aggregate thickness greater than 6 ft.

In summary, the majority of the Ferron coal resources 

are poorly defi ned by USGS reliability standards; they are 

primarily less than 6 ft thick, deeper that 100 ft, and lie 

within Garfi eld County. The in-place coal resources for the 

total Ferron zone are summarized by thickness, depth, reliability category, and county in tables 2, 3, and 4. Readers 

should note that the individual resource categories in these and 

other resource tables may not sum to totals at the bottoms of 

the tables due to independent rounding.

Coal Resources of the Henry Mountains Coal Field, Utah R13
Thickness and Geometry of 

Muley Canyon Coal

The upper part of the Muley Canyon Member is a nonmarine coal-bearing interval with thicknesses ranging from 92 

to 209 ft thick and averaging about 150 ft. This stratigraphic 

interval, referred to as the Muley Canyon coal zone in this 

report, commonly contains three to four coal beds, but locally 

has as many as 10 beds. Individual coal beds range from 0 

to 13.4 ft thick and are commonly 2–5 ft thick; aggregate 

thickness of coal is as much as 27.5 ft (fi g. 8). Most of the area 

underlain by this zone has at least 5 ft of total coal, and about 

half of the area has 10 ft or more of total coal.

Unlike the Ferron coal, the Muley Canyon coal occurs 

throughout most the coal fi eld (fi g. 8). The Muley Canyon coal 

is thickest in elongate pods oriented in an east-west direction 

that tend to be thicker on the west side of the Henry Mountains 

Basin and thin gradually to the east. The largest thick pod of 

coal lies in the center of the basin, as was the case with the 

Ferron coals (fi g. 6).

Depth to Muley Canyon Coal Zone

Broad expanses of the coal zone in the Muley Canyon at 

the northern and southern ends of this unit’s exposures are less 

than 100 ft deep (see fi g. 9) Thus, some of the thicker coal 

beds under parts of Wildcat Mesa, Cave Flat, and Swap Mesa 

are potentially surface-minable. The extensive, thick (>24 ft) 

Muley Canyon coal under Tarantula Mesa reaches a maximum 

depth of slightly more than 1,000 ft, and therefore it is at 

shallow to moderate depths for underground mining methods.

Chemistry of Muley Canyon Coal

The coal beds in the Muley Canyon coal zone have been 

more extensively sampled than those in the Ferron. The coals 

sampled come primarily from the northern and southern ends 

of the area underlain by the Muley Canyon coal zone where 

there is shallow cover and not from the deeper, central area. 

The Muley Canyon coal analyses, from seven outcrops and 30 

drill cores, are listed in table 5. 

The Muley Canyon coal has an apparent rank of subbituminous A to high-volatile bituminous C (Hatch and others, 

1979; Law, 1980), a slightly lower rank than the Ferron coals 

that translates to a lower heat content and higher moisture 

content. The mean ash content of the Muley coals, 11.74 

percent, is less than that of the Ferron coals; for comparison, 

the Utah coal produced from the Wasatch Plateau and Book 

Cliffs coal fi elds typically has an average ash content of about 

10 percent. Figure 10 shows the variation in the ash content of 

the Muley Canyon coals across the coal fi eld. The ash content 

is highest in two, east-west-trending lobate areas—one each in 

the northern part and the southern part of the fi eld.

The sulfur content of the Muley Canyon coals ranges 

as high as 3.2 percent (table 5), which is as high as the 

Ferron coals, but the mean sulfur content of the Muley Canyon 

samples is considerably less, at 0.9 percent. In comparison, 

the average sulfur content of coal presently produced from 

the Wasatch Plateau and Book Cliffs coal fi elds is 0.5 to 0.7 

percent. The variation in sulfur content of the Muley Canyon 

coals across the coal fi eld is shown in fi gure 11. One east-westtrending, high-sulfur area coincides with the northern high-ash 

area.

The heat content of Muley Canyon coals ranges from 

7,710 to 12,491 Btu per pound and averages 10,086 Btu per 

pound (table 5). Figure 12 shows that the heat-content distribution across the coal fi eld consists of east-west trends with low 

heat areas corresponding directly with areas having high ash 

content. In addition to this primary east-west trend, the heat 

content values of the Muley Canyon coals appear to be slightly 

higher on the east side of the fi eld than on the west, suggesting 

that the eastern coals were possibly thermally upgraded by the 

intrusion of the Henry Mountains laccoliths.

The ash chemistry of some of the Muley Canyon coals 

has been studied by Hatch and others (1979). Chemical 

analyses of the major oxides in the Muley Canyon coal ash 

(table 6) can be used to predict coal utilization characteristics, 

such as boiler slagging and fouling characteristics. The 

physical and chemical transformations that the minerals in the 

coal ash undergo during combustion is a complex process. 

Vaninetti and Busch (1981) defi ne slagging as the buildup 

of molten ash materials within the lower furnace section 

of a boiler and fouling as the accumulation of sintered 

ash in the convective passes section of a boiler. Both of 

these problems reduce boiler effi ciency, increase operating 

costs, and shorten boiler life. Various indices can predict 

the combustion characteristics of coal ash, and two of them 

are presented in table 7. The fi rst step in analyzing ash 

combustion properties is to determine the type of coal 

ash present. Coal ash is characterized as either lignitic or 

bituminous depending on the value determined by summing 

CaO and MgO and dividing by Fe2O3. Coal ash is termed 

lignitic when the value is greater than 1.0 and bituminous 

when the value is less than 1.0. Most of the Muley Canyon 

ash analyses fall in the lignitic ash category, although two ash 

samples fall in the bituminous ash category. Both of these 

bituminous ash analyses are from coal samples with high iron 

and sulfur content, indicating a high pyrite content.

Text continues on p. 22

R14 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
Table 5. Proximate analyses of Muley Canyon coal samples (as-received basis). 

 Cadastral Moisture Volatile matter Fixed carbon Ash Sulfur Btu per 

 location (percent) (percent) (percent) (percent) (percent) pound 

 22-31S-8E 11.5 35.3 40.3 12.9 0.8 10,110 

 22-31S-8E 11.0 35.4 37.0 16.6 0.4 9,440 

 22-31S-8E 9.5 32.7 33.3 24.5 2.0 8,510 

 23-31S-8E 11.6 36.6 42.7 9.1 0.6 10,620 

 23-31S-8E 10.3 36.0 36.3 17.4 0.7 9,400 

 23-31S-8E 10.9 38.2 42.4 8.5 1.0 10,790 

 -31S-8E 14.28 33.47 41.97 10.64 0.66 9,986 

 36-31S-8E 13.51 31.99 35.69 18.81 0.53 9,015 

 36-31S-8E 13.87 34.37 41.33 10.43 1.0 10,204 

 07-31S-9E 6.36 39.52 44.14 9.98 0.67 9,698 

 07-31S-9E 13.1 34.0 45.1 7.8 0.7 10,210 

 07-31S-9E 9.5 35.0 45.8 9.7 0.7 10,480 

 17-31S-9E 13.0` 35.0 37.7 14.3 0.7 9,670 

 18-31S-9E 12.5 33.6 35.7 18.2 0.7 9,300 

 18-31S-9E 12.7 32.2 32.0 23.1 3.2 8,520 

 19-31S-9E 12.5 34.6 39.3 13.6 0.5 9,990 

 19-31S-9E 13.7 36.5 42.7 7.1 0.6 10,600 

 20-31S-9E 11.6 35.4 36.3 16.7 2.8 9,610 

 20-31S-9E 12.1 37.1 41.4 9.4 0.4 10,660 

 27-31S-9E 6.9 38.0 49.1 6.0 0.7 11,130 

 30-31S-9E 9.3 37.2 46.7 6.8 0.8 10,900 

 30-31S-9E 11.5 38.5 40.8 7.7 1.5 12,491 

 -32S-9E 9.2 35.4 44.9 10.5 0.7 9,590 

 05-32S-9E 13.6 32.56 39.3 14.54 0.8 9,597 

 05-32S-9E 13.6 35.25 36.19 14.96 0.69 9,652 

 12-33S-8E 14.7 27.4 30.6 27.3 0.4 7,710 

 24-33S-8E 14.37 35.57 35.14 16.92 0.99 9,156 

 24-33S-8E 14.37 34.92 42.47 8.24 1.16 10,231 

 24-33S-8E 14.37 35.61 45.48 4.54 1.09 10,759 

 02-33S-9E 10.48 38.29 45.25 5.98 0.78 11,468 

 11-33S-9E 11.34 36.09 43.86 8.71 0.46 10,856 

 11-33S-9E 13.7 37.2 44.19 4.91 0.47 11,121 

 14-33S-9E 12.29 36.65 45.49 5.57 0.55 11,147 

 22-33S-9E 13.3 36.23 39.33 11.14 1.05 8,178 

 23-33S-9E 13.48 34.45 43.61 8.46 0.83 10,660 

 23-33S-9E 13.3 36.36 43.36 5.97 0.67 11,010 

 23-33S-9E 14.28 34.89 43.51 7.32 1.12 10,718 

Mean 12.1 35.34 40.82 11.74 0.9 10,086 

Minimum 6.36 27.4 30.6 4.54 0.4 7,710 

Maximum 14.7 39.52 49.1 27.3 3.2 12,491 

Standard deviation 2.04 2.2 4.38 5.6 0.6 970 

Statistics for 34 samples with less than 20 percent ash 

Mean 12.08 35.74 41.60 10.57 0.8 10,248 

Minimum 6.36 31.99 35.14 4.54 0.4 8,178 

Maximum 14.37 39.52 49.10 18.81 2.8 12,491 

Standard deviation 2.03 1.66 3.64 4.14 0.4 829 

Coal Resources of the Henry Mountains Coal Field, Utah R15
0 1 2 3 4 5 Miles

Utah

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S 

R7E R8E R9E R10E R11E R12E

LEGEND

Coal interval >24ft

Coal interval 18-24 ft

Coal interval 14-18 ft

Coal interval 10-14 ft

Coal interval 6-10 ft

Coal interval 2-6 ft

Coal interval 0-2 ft

Muley Canyon coal zone outcrop

Figure 8. Isopach map of Muley Canyon coal zone.

R16 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
0 1 2 3 4 5 Miles

Utah

N

LEGEND

Overburden thickness > 1000ft

Overburden thickness 100-1000ft

Overburden thickness 0-100ft

Muley Canyon coal zone outcrop

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S

R7E R8E R9E R10E R11E R12E

Figure 9. Overburden map of Muley Canyon coal zone.

Coal Resources of the Henry Mountains Coal Field, Utah R17
0 1 2 3 4 5 Miles

Utah

LEGEND

Ash content isopleth

Core hole with ash content data

Muley Canyon coal zone outcrop

10.6

18.0

11.7 10.4

18.8

20.6

14.3

16.7

10.4

7.2 6.0

9.4

10.0

10.0

10.5 15.0

10.0

9.9

27.3 20.0

15.0

7.2

5.6

4.9

8.7

6.0

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S

R7E R8E R9E R10E R11E R12E

N

Figure 10. Map showing ash content of coal in Muley Canyon coal zone (as-received basis).

R18 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
Utah

0.98

1.10

0.80

1.0

0.53

1.0

0.67

0.70

1.95

2.80 0.40 2.0

0.60

0.70

1.15

0.70

0.40

1.08

1.0 0.87

0.55

0.47

0.46

0.78

N

Sulfur (%) content isopleth

Muley Canyon coal zone outcrop

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S

R7E R8E R9E R10E R11E R12E

0 1 2 3 4 5 Miles

LEGEND

Core hole with sulfur content data

Figure 11. Map showing sulfur content of coal in Muley Canyon coal zone (as-received basis).

Coal Resources of the Henry Mountains Coal Field, Utah R19
0 1 2 3 4 5 Miles

Utah

N

Heat content (Btu/lb) isopleth

Muley Canyon coal zone outcrop

7710

10049

9000

10,000

11,000

11468

10856

11121

11147

10796

9590

9000

10,000

11695 11,000

10295

9610

10660

9670

9698

9986

9353

10270

8910

11130

10204

9015

T27S

T28S

T29S

T30S

T31S

T32S

T33S

T34S

T35S

R7E R8E R9E R10E R11E R12E

LEGEND

Core hole with heat content data

Figure 12. Map showing heat content of coal in Muley Canyon coal zone (as-received basis).

R20 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
Table 6. Major oxide composition (in percent) of ash from 13 Muley Canyon coal samples from the Henry 

Mountains coal field. 

[Standard dev., standard deviation] 

Cadastral Acidic oxides Basic oxides 

location SiO2 Al2O3 TiO2 CaO MgO Na2O K2O Fe2O3 Ash 

22-31S-8E 60.0 12.0 1.00 8.9 2.00 0.75 0.44 5.8 13.0 

22-31S-8E 54.0 27.0 0.79 9.0 1.03 0.95 1.20 1.0 19.6 

22-31S-8E 57.0 24.0 1.00 6.0 1.18 0.28 1.10 1.0 10.2 

23-31S-8E 53.0 14.0 0.88 13.0 2.09 2.75 0.43 3.5 9.8 

23-31S-8E 51.0 23.0 0.88 14.0 1.27 1.09 0.66 1.9 20.0 

23-31S-8E 38.0 22.0 1.20 16.0 2.53 1.62 0.31 4.9 9.1 

17-31S-9E 58.0 17.0 0.87 10.0 1.96 0.13 0.73 3.3 14.5 

18-31S-9E 61.0 17.0 1.00 6.2 1.58 0.54 1.20 2.5 19.7 

18-31S-9E 50.0 12.0 0.70 6.5 1.49 0.92 1.20 17.0 19.6 

19-31S-9E 65.0 14.0 1.00 8.4 1.76 0.51 0.62 2.5 15.6 

19-31S-9E 30.0 11.0 0.60 29.0 2.80 1.30 0.48 4.4 8.3 

20-31S-9E 65.0 7.8 1.20 12.0 2.31 0.24 0.54 3.1 10.8 

20-31S-9E 46.0 18.0 1.10 7.5 1.36 0.40 0.74 15.0 18.3 

Mean 52.9 16.8 0.94 11.3 1.80 0.88 0.74 5.5 14.5 

Minimum 30.0 7.8 0.60 6.0 1.03 0.13 0.31 1.0 8.3 

Maximum 65.0 27.0 1.20 29.0 2.80 2.75 1.20 17.0 20.0 

Standard dev. 10.2 5.8 0.18 6.2 0.54 0.71 0.32 4.9 4.6 

Table 7. Ash type, fouling, and slagging evaluation of the oxide composition of Muley 

Canyon coal ash. 

[Base/acid ratio = CaO+MgO+Na2O+K2O+Fe2O3/SiO2+Al2O3+TiO2; med, medium] 

Cadastral Ash type Fouling severity Slagging severity 

location (CaO+MgO/Fe2O3) (Percent Na2O) (Base/acid ratio) 

22-31S-8E 1.88 (lignitic) 0.75 (low) 0.245 (low) 

22-31S-8E 10.03 (lignitic) 0.95 (low) 0.161 (low) 

22-31S-8E 1.14 (lignitic) 0.28 (low) 0.181 (low) 

23-31S-8E 4.31 (lignitic) 2.75 (low) 0.320 (med-severe) 

23-31S-8E 8.04 (lignitic) 1.09 (low) 0.253 (med-severe) 

23-31S-8E 3.78 (lignitic) 1.62 (low) 0.414 (med-severe) 

17-31S-9E 3.62 (lignitic) 0.13 (low) 0.212 (low) 

18-31S-9E 3.11 (lignitic) 0.54 (low) 0.152 (low) 

18-31S-9E 0.47 (bituminous) 0.92 (medium) 0.432 (low) 

19-31S-9E 4.06 (lignitic) 0.51 (low) 0.172 (low) 

19-31S-9E 7.23 (lignitic) 1.30 (low) 0.913 (low) 

20-31S-9E 4.62 (lignitic) 0.24 (low) 0.246 (low) 

20-31S-9E 0.59 (bituminous) 0.40 (low) 0.384 (low) 

Mean 4.07 (lignitic) 0.88 (low) 0.314 (med-severe) 

Coal Resources of the Henry Mountains Coal Field, Utah R21
Sodium content in the ash is critical to various indices of 

ash-fouling potential, and the simplest indicator of fouling is 

the total sodium oxide content of the ash alone. Bituminous 

and lignitic ash coals respond differently to increased sodium 

oxide content, with coals in the bituminous category being 

much more sensitive to small increases in sodium oxide. The 

change in ash-fouling tendency with increasing sodium oxide 

content according to Vaninetti and Busch (1981) is as follows:

to 3 mi from a thickness-measurement point). None of the coal 

resources is in the hypothetical category (more than 3 mi from 

a thickness-measurement point).

Measurement of depth of cover shows that 25.6 percent, 

or 391 million short tons, lies within 100 ft or less of the 

ground surface. The remainder are all less than 2,000 ft deep 

and most are under less than 1,000 ft of overburden (fi g. 9).

A review of the coal resources by coal-thickness category 

shows that 91 percent has a total coal thickness of 6 ft or 

greater and that about 70 percent of the coal resources has a 

total coal thickness of more than 10 ft. In much of the area 

below Tarantula Mesa, the Muley Canyon coal zone consists of 

a single thick bed from 6 to 12 ft thick (Tabet, 1999). Only 9 

percent of the coal resources has a thickness of less than 6 ft. 

In summary, the Muley Canyon coal resources are, for 

the most part, well defi ned according to USGS reliability 

standards, greater than 6 ft thick, deeper that 100 ft, and 

within Garfi eld County. The in-place coal resources for the 

total Muley Canyon coal zone are summarized by thickness, 

depth, reliability, and county categories in tables 8, 9, and 

10. Readers should again note that the individual resource 

categories in the tables may not sum to totals at the bottoms of 

the tables due to independent rounding.

Coal Development Potential

The coal resources of the Ferron Sandstone Member 

of the Mancos Shale offer limited development potential for 

mining, commonly being too thin and discontinuous to be 

of economic interest. The Ferron coals are further hampered 

by poor coal quality—both ash and sulfur content are high. 

Limited areas might be suitable for surface mining, but environmental constraints could possibly restrict development. The 

thick, shallow deposits at the north end of the coal fi eld near 

Factory Butte offer the best development potential. This area 

contains about 20 million short tons of coal under less than 

100 ft of cover that could be surface-mined if warranted by 

marketing conditions and if mining could be conducted in an 

environmentally acceptable manner.

Fouling Tendency 

 Factor Ash type Low Medium High Severe 

Na2O in ash (%) bituminous <0.5 0.5–1.0 1.0–2.5 >2.5 

Na2O in ash (%) lignitic <3.0 3.0–5.0 >5.0 

When examining just the sodium content of the ash, all 

but one of the Muley Canyon coal ash samples fall in the 

low-fouling-potential range.

If coal from the Muley Canyon were mined, various 

quality-control strategies including blending, selective mining, 

or selective washing could probably produce a low-ash, lowsulfur coal similar to that presently produced in central Utah. 

The coal that could be produced is predicted to have lowslagging and low-fouling boiler combustion properties based 

on ash chemistry.

Coal Resources of the 

Muley Canyon Sandstone Member

The Muley Canyon contains 1,526.1 million short tons 

of in-place coal resources. All but half a percent of the coal 

resources lies in Garfi eld County. Because of extensive exploration data, 62 percent, or 945.6 million short tons, of the total 

coal resources falls in the demonstrated, or the most reliable, 

resource category. The remaining 38 percent, 580.5 million 

short tons, falls in the inferred resource category, (at least 0.75 

Table 8. Total Muley Canyon coal zone resources by thickness and depth of cover. 

[All coal beds greater than or equal to 1 ft thick; figures in millions of short tons. DEM, 

demonstrated; INF, inferred] 

Depth 2–6 ft thick 6–10 ft thick 10+ ft thick 

(ft) DEM INF DEM INF DEM INF Total 

0-100 78.3 4.4 107.4 7.6 172.4 20.9 391.0 

100-1,000 42.1 11.3 118.5 75.7 383.7 449.4 1,080.7 

1,000-2,000 1.6 0.0 4.9 1.2 36.8 9.9 54.4 

TOTAL 121.9 15.8 230.9 84.5 592.8 480.2 1,526.1 

R22 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
The coal resources of the Muley Canyon Member are 

generally thicker and more persistent in areal extent than 

the Ferron coal resources in the Henry Mountains coal 

fi eld. Thick, suffi ciently large concentrations of both surfaceand underground-minable coal deposits exist in the Muley 

Canyon. During the 1970’s, Amax Coal Company (now 

RAG International Mining) delineated approximately 120 

million short tons of recoverable surface-minable coal divided 

among three tracts located at Wildcat Mesa, Swap Mesa, 

and Cave Flat. Prior to issuing coal leases to Amax, the 

BLM conducted a survey in 1982 to determine which lands 

were unsuitable for surface mining. As a result, the areas 

containing all 22 million short tons of coal in the vicinity of 

Cave Flat, 20 million of the 35 million short tons of coal in 

the Swap Mesa area, and 3 million of the 63 million short 

tons of coal in the Wildcat Mesa area were deemed unsuitable 

for surface mining. This ruling essentially precluded surface 

coal mining from southern end of the Muley Canyon coal 

area, but it allowed for the possibility that 60 million short 

tons of coal under Wildcat Mesa could be surface-mined. 

The greatest coal development potential for the coal fi eld 

lies in the large amounts of deep Muley Canyon coal under 

Tarantula Mesa. One of the coal beds is 6–15 ft thick, and it 

occurs under no more than 1,100 ft of overburden—favorable 

conditions for underground mining (Tabet, 1999). Access to 

the underground coal could be achieved through openings in 

exposures either on the east or west side of the fi eld or, if 

necessary, via a shallow shaft. The area under Tarantula Mesa 

contains an estimated 450 million short tons of in-place, deep 

coal resources in one thick coal bed. Assuming roof and 

fl oor conditions are not adverse, these coal resources are large 

enough to support several deep mines producing as much as 2 

to 3 million short tons of coal per year. 

The Muley Canyon coal is of better quality than the Ferron 

coal, and thus probably could supply a suitable product for 

electric-power generation despite containing higher amounts of 

ash and sulfur in places. The coal is slightly inferior in quality 

to that typically produced from the Blackhawk Formation mines 

in the central Utah coal fi elds. Environmental, wilderness, and 

transportation issues are possible deterrents to future development of at least part of the Muley Canyon coal deposits, but the 

actual amount of these resources suitable for eventual mining 

awaits further and more detailed engineering, environmental, 

geologic, and marketing studies.

Table 9. Total Muley Canyon coal zone resources by thickness and county. 

[All coal beds greater than or equal to 1 ft thick; figures in millions of short tons. DEM, 

demonstrated; INF, inferred] 

County 2–6 ft thick 6–10 ft thick 10+ ft thick 

 DEM INF DEM INF DEM INF Total 

Wayne 7.3 0.0 0.2 0.0 0.0 0.0 7.5 

Garfield 114.6 15.8 230.7 84.5 592.8 480.2 1,518.6 

TOTAL 121.9 15.8 230.9 84.5 592.8 480.2 1,526.1 

Table 10. Total Muley Canyon coal zone resources by thickness and township tier. 

[All coal beds greater than or equal to 1 ft thick; figures in millions of short tons. DEM, 

demonstrated; INF, inferred] 

Tier 2–6 ft thick 6–10 ft thick 10+ ft thick 

 DEM INF DEM INF DEM INF Total 

T. 30 S. 7.3 0.0 0.2 0.0 0.0 0.0 7.5 

T. 31 S. 45.5 2.5 89.1 6.5 86.0 0.0 229.6 

T. 32 S. 21.5 10.9 61.0 44.4 205.1 293.8 636.7 

T. 33 S. 40.7 0.6 77.0 27.5 259.8 169.2 574.8 

T. 34 S. 6.9 1.8 3.6 6.1 41.9 17.2 77.5 

TOTAL 121.9 15.8 230.9 84.5 592.8 480.2 1,526.1 

Coal Resources of the Henry Mountains Coal Field, Utah R23
References Cited

Billingsley, G.H., Huntoon, P.W., and Breed, W.J., 1987, Geologic map 

of Capitol Reef National Park and vicinity, Emery, Garfi eld, Millard, 

and Wayne Counties, Utah: Utah Geological and Mineralogical 

Survey Map 87, scale 1:62,500, 3 sheets. 

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., 1975, Geology and mineral resources of Garfi eld 

County, Utah: Utah Geological and Mineral Survey Bulletin 107, 

175 p.

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: Utah Geological and Mineralogical Survey Bulletin 118, p. 1–26.

Eaton, J.G., 1990, Stratigraphic revision of Campanian (Upper Cretaceous) rocks in the Henry Basin, Utah: The Mountain Geologist, v. 

27, no. 1, p. 27–38.

Gilbert, G.K., 1877, Report on the geology of the Henry Mountains: 

U.S. Geographical and Geological Survey, Rocky Mountain Region, 

160 p.

Hatch, J.R., Affolter, R.H., and Law, B.E., 1979, Chemical analyses 

of coal from the Emery and Ferron Sandstone Members of the 

Mancos Shale, Henry Mountains fi eld, Wayne and Garfi eld Counties, Utah: U.S. Geological Survey Open-File Report 79-1097, 24 p.

Hill, R.B., 1982, Depositional environments of the Upper Cretaceous 

Ferron Sandstone south of Notom, Wayne County, Utah: Brigham 

Young University Geology Studies, v. 29, pt. 2, p. 59–83.

Hunt, C.B., and Miller, R.L., 1946, General geology of the region—

Stratigraphy, in Hunt, C.B., ed., Guidebook to the Geology and 

Geography of the Henry Mountains Region: Utah Geological Society Guidebook, no. 1, p. 6–10. 

Hunt, C.B., Averitt, Paul, and Miller, R.L., 1953, Geology and geography 

of the Henry Mountains region: U.S. Geological Survey Professional 

Paper 228, 234 p.

Larson, M.J., Bromfi eld, C.S., Dubiel, R.F., Patterson, C.G., and Peterson, Fred, 1985, Geologic map of the Little Rockies Wilderness 

Study Area and the Mt. Hillers and Mt. Pennell study areas and 

vicinity, Garfi eld County, Utah: U.S. Geological Survey Miscellaneous Field Studies Map MF 1776-B, scale 1:50,000, 1 sheet. 

Law, B.E., 1977, Geophysical logs of test holes from the Henry Mountains coal fi eld, Garfi eld and Wayne Counties, southeastern Utah: 

U.S. Geological Survey Open-File report 77-41, 4 p., 28 logs.

Law, B.E., 1979a, Coal deposits of the Emery coal zone, Henry Mountains coal fi eld, Garfi eld and Wayne Counties, Utah: U.S. Geological 

Survey Miscellaneous Field Studies Map MF 1082-A, scale 1:62,500, 

2 sheets.

Law, B.E., 1979b, Surface coal sections in the Emery coal zone, Henry 

Mountains coal fi eld, Utah: U.S. Geological Survey Miscellaneous 

Field Studies Map MF 1082-B, 2 sheets.

Law, B.E., 1980, Tectonic and sedimentological controls of 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 Guidebook 8, p. 323–335.

McKell, C.M., Fuhrman, Jerry, Gifford, G.F., Richardson, S.G., Southard, 

A.G., Van Epps, Gordon, Williams, J.S., and Workman, Gar, 1978, 

Rehabilitation potential for the Henry Mountains coal fi eld: U.S. 

Bureau of Land Management EMRIA Report No. 15, 289 p.

Morton, L.B., 1984, Geology of the Mount Ellen quadrangle, Henry 

Mountains, Garfi eld County, Utah: Brigham Young University Geology Studies, v. 331, p. 67–95.

Morton, L.B., 1986, Provisional geologic and coal resources map 

for the Mt. Ellen quadrangle, Henry Mountains, Garfi eld County, 

Utah: Utah Geological and Mineral Survey Map 90, 3 plates, scale 

1:24,000, 15 p.

Patterson, C.G., Bromfi eld, C.S., Dubiel, R.F., Faulds, J.E., Larson, 

M.J., Milde, P.G., and Peterson, Fred, 1985, Geologic map of the 

Mt. Ellen–Blue Hills Wilderness Study Area and Bull Mountain 

study area, Garfi eld and Wayne Counties, Utah: U.S. Geological 

Survey Miscellaneous Field Studies Map MF 1756-B, scale 1:50,000, 

1 sheet. 

Peterson, Fred, and Ryder, R.T., 1975, Cretaceous rocks in the Henry 

Mountains region, Utah, and their relation to neighboring regions, 

in Fassett, J.E., ed., Canyon Country: Four Corners Geological Society, Eighth Field Conference Guidebook, p. 167–189.

Peterson, Fred, Ryder, R.T., and Law, B.E., 1980, Stratigraphy, sedimentology, and regional relationships of the Cretaceous System 

in the Henry Mountains region, Utah, in Picard, M.D., ed., Henry 

Mountains Symposium: Utah Geological Association Guidebook, 

p. 151–170.

Smith, C.T., 1983, Geology, depositional environments, and coal 

resources of the Mt. Pennell 2 NW quadrangle, Garfi eld County, 

Utah: Brigham Young University Geology Studies, v. 30, pt. 1, 

p. 145–169.

Spieker, E.M., and Reeside, J.B., Jr., 1926, Upper Cretaceous shoreline 

in Utah: Geological Society of America Bulletin, v. 37, p. 429–438.

Tabet, D.E., 1999, Coal resources of the Henry Mountains coalfi eld: 

Utah Geological Survey Open-File Report 362, 32 p., 6 plates, scale 

1:100,000.

Thompson, K.C., 1967, Geologic map of most of Wayne County: 

Utah Geological and Mineralogical Survey, unpublished map, scale 

1:63,360, 1 sheet.

Uresk, Jack, 1979, Sedimentary environment of the Cretaceous Ferron 

Sandstone near Caineville, Utah: Brigham Young University Geology Studies, v. 26, pt. 2, p. 81–100.

U.S. Bureau of Land Management, 1990, Utah BLM Statewide wilderness fi nal environmental impact statement, overview: Utah State 

Offi ce of the U.S. Bureau of Land Management, v. 1, 209 p., 12 

appendixes. 

U.S. Bureau of Land Management, 1999, Utah wilderness inventory: 

U.S. Department of the Interior, Bureau of Land Management, 142 

p., 1 appendix. 

R24 Geologic Assessment of Coal in the Colorado Plateau: Arizona, Colorado, New Mexico, and Utah
Vaninetti, G.E., and Busch, C.F., 1981, A utility perspective on the 

signifi cance of mineral analysis of ash data: Preprint of a paper 

presented at the First Coal Testing Conference, Lexington, Kentucky, March 1981, 10 p.

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

Coal resource classifi cation system of the U.S. Geological Survey: 

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

Whitlock, W.W., 1984, Geology of the Steele Butte quadrangle, Garfi eld County, Utah: Brigham Young University Geology Studies, v. 31, 

pt. 1, p. 141–165.

National Coal

Resource

Assessment

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Coal Resources of the Henry Mountains Coal Field, Utah R25