Coal Resources of the 

Fruitland Formation in Part of the 

Ute Mountain Ute Indian Reservation, 

San Juan County, New Mexico 

Prepared in cooperation with the 

U.S. Bureau of Indian Affairs and the 

Ute Mountain Ute Tribe 

Coal Resources of the 

Fruitland Formation in Part of the 

Ute Mountain Ute Indian Reservation, 

San juan County, New Mexico 

By LAURA N. ROBINSON ROBERTS 

Prepared in cooperation with the 

U.S. Bureau of Indian Affairs and the 

Ute Mountain Ute Tribe 

U.S. GEOLOGICAL SURVEY BULLETIN 1938 
U.S. DEPARTMENT OF THE INTERIOR 

MANUEL LUJAN, JR., Secretary 

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director 

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

purposes only and does not constitute endorsement by the U.S. Government, 

nor impute responsibility for any present or potential effects on the natural 

resources. 

UNITED STATES GOVERNMENT PRINTING OFFICE: 1991 

For sale by the 

Books and Open-File Reports Section 

U.S. Geological Survey 

Federal Center 

Box 25425 

Denver, CO 80225 

Library of Congress Cataloging-in-Publication Data 

Roberts, Laura N. Robinson. 

Coal resources of the Fruitland Formation in part of the Ute Mountain Ute 

Indian Reservation, San Juan County, New Mexico I by Laura N. Robinson 

Roberts. 

p. em. - (U.S. Geological Survey bulletin ; 1938) 

"Prepared in cooperation with the U.S. Bureau of Indian Affairs and the Ute 

Mountain Ute tribe." 

Includes bibliographical references (p. ). 

Supt. of Docs. no.: I 19.3: 1938 

1. Coal-Fruitland Formation (Col. and N.M.) 2. Coai-Ute Mountain Indian 

Reservation. I. United States. Bureau of Indian Affairs. II. Ute Mountain 

Ute Tribe. Ill. Title. IV. Series. 

QE75.89 no. 1938 

[TN805.N6] 

557.3 s-dc20 

[553.2'4'0978982) 9Q-3798 

CIP 
CONTENTS 

Abstract 1 

Introduction 1 

Location and access 1 

Previous investigations 2 

Method of investigation 3 

Acknowledgments 3 

Structure 3 

Stratigraphy of Fruitland Formation 3 

Coal deposits 5 

Description of coal beds 7 

Main bed 8 

Upper Main bed 9 

Ute Canyon and Lower Ute Canyon beds 9 

Local1 bed 9 

Local2 bed 9 

Coal quality 9 

Coal resources 10 

Potential for surface mining 12 

Potential for coal bed methane 14 

References cited 15 

PLATE 

[Plate is in pocket] 

1. Coal resources of the Fruitland Formation in the Ute Mountain Ute Indian 

Reservation, San Juan County, New Mexico: 

Map A. Geologic map of the southeastern corner of the Ute Mountain 

Ute Indian Reservation, San Juan County, New Mexico. 

Map B. Structure contour map of the top of the Main coal bed. 

Map C. Isopachs of the Main coal bed and overburden. 

Map D. Isopachs of the interval between the Upper Main and Main coal 

beds. 

Map E. Isopachs of the Upper Main coal bed and overburden. 

Map F. Isopachs of the interval between the Ute Canyon coal bed and the 

Main or Upper Main coal bed. 

Map G. Isopachs of the Ute Canyon coal bed and overburden. 

Map H. Isopachs of total coal in the Fruitland Formation and of 

overburden. 

Section A. Cross section from north to south showing thickness 

and correlation of coal beds. 

Section B. Cross section from southwest to northeast showing 

thickness and correlation of coal beds. 

Section C. Cross section from west to east showing thickness and 

correlation of coal beds. 

Section D. Measured coal sections. 

Contents Ill 
FIGURES 

1. Map showing Ute Mountain Ute Indian Reservation and location of study 

area 2 

2. Representative geophysical logs used to determine coal-bed thickness in drill 

holes 5 

3. Stratigraphic cross section showing Upper Cretaceous and Tertiary rocks from 

southwest to northeast across the San Juan Basin in New Mexico and 

Colorado 6 

4. Map showing location of cross sections 7 

TABLES 

1. Drill holes in and near the Ute Mountain Ute Indian Reservation that were 

used in coal resource evaluation 4 

2. Names used for coal beds in the study area 7 

3. Thickness of coal and depth to correlated coal beds greater than 1.2 feet 

thick 8 

4. Analyses of coal in the Fruitland Formation from Western Coal Company 

core holes 10 

5. Average heat-of-combustion and moisture, ash, and sulfur content on an asreceived basis, Hardgrove Grindability Index, and apparent rank, by coal bed, 

of seven coal samples from the southeastern part of the Ute Mountain Ute 

Indian Reservation 10 

6. Summary of estimated coal resources, by bed 11 

7. Estimated total coal resources of the Fruitland Formation as of July 1, 

1987 12 

8. Estimated coal resources, by bed thickness 12 

9. Estimated coal resources, by degree of geologic assurance 13 

10. Estimated coal resources, by overburden thickness and bed thickness 13 

11. Estimated coal resources, by overburden thickness and degree of geologic 

assurance 14 

CONVERSION FACTORS 

For readers who wish to convert measurements from U.S. customary units to the metric system of units, 

the conversion factors are listed below. 

U.S. customary unit Multiply by To obtain metric unit 

foot (ft) 0.305 meter 

mile (mi) 1.609 kilometer 

square mile (mi2

) 2.590 square kilometer 

acre 0.405 hectometer 

short ton 0.907 metric ton 

British thermal unit 0.556 kilocalorie per 

per pound (Btu/lb) kilogram 

IV Contents 
Coal Resources of the Fruitland F:ormation in 

Part of the Ute Mountain Ute lndic:tn Reservation, 

San Juan County, New Mexico 

By Laura N. Robinson Roberts 

Abstract 

The coal-bearing Upper Cretaceous Fruitland 

Formation occupies an area of about 14 square miles in the 

extreme southeast corner of the Ute Mountain Ute Indian 

Reservation in San Juan County, New Mexico. In this area, 

the Fruitland Formation contains an estimated 252 million 

short tons of coal in beds that range from 1.2 to 14 feet thick. 

About 100 million short tons of coal occur under less than 500 

feet of overburden in the Ute Canyon, Upper Main, and Main 

coal beds. These three coal beds reach a cumulative coal 

thickness of about 18 feet in a stratigraphic interval that 

averages about 120 feet thick in the prospecting permit area, 

which is located in the extreme southwestern part of the 

study area. The southwestern part of the study area is 

probably best suited for surface mining, although steep dips 

may reduce minability locally. A major haul road that was 

recently constructed across the eastern half of the study area 

greatly improves the potential for surface mining. 

Core sample analyses indicate that the apparent rank 

of the Ute Canyon, Upper Main, and Main coal beds is 

high-volatile C bituminous. Average heat-of-combustion on 

an as-received basis is 10,250 British thermal units per 

pound, average ash content is 15.5 percent, and average 

sulfur content is 1.0 percent. 

INTRODUCTION 

The Division of Energy and Mineral Resources of 

the U.S. Bureau of Indian Affairs and the U.S. 

Geological Survey initiated a program to assess the 

energy resources of the Ute Mountain Ute Indian 

Reservation at the request of the Ute Mountain Ute 

Tribe. As part of that program, the U.S. Geological 

Survey studied the distribution of coal-bearing rocks 

Manuscript approved for publication, March 29, 1990. 

within the Reservation in order to determine the extent, 

quality, and quantity of the coal deposits. This report 

presents the results of that study. 

Coal within the Reservation occurs in the Dakota 

Sandstone and in the Menefee and Fruitland Formations, 

all of which are Late Cretaceous in age. Coal beds in the 

Dakota Sandstone are discontinuous and contain 

numerous partings; these beds are deeper than 1,000 ft in 

the eastern half of the Reservation. The Menefee 

Formation underlies the eastern half of the Reservation 

at depths from 0 ft (outcrop) to 3,000 ft and contains coal 

beds in two zones: one zone near the top of the formation 

and another zone near the base. The coal beds in the 

Menefee Formation are thin and discontinuous. Shomaker and Holt (1973) described the coals, reported coal 

resources of the Dakota Sandstone and the Menefee 

Formation, and suggested locations that are best suited 

for auger mining in the Menefee Formation. 

Only the coal beds of the Fruitland Formation were 

studied in detail for this report. Although the Fruitland 

Formation occupies only a small area in the southeastern 

part of the Reservation, it contains coal beds that have 

potential for surface mining. Since the publication of 

Shomaker and Holt's (1973) report, and prior to July 

1987, 20 oil and gas wells were drilled through the 

Fruitland Formation. The coal resource estimates of the 

Fruitland Formation on the Reservation were refined 

using data from these drill holes. 

Location and Access 

The coal-bearing Fruitland Formation underlies 

about 14.5 m? in the southeastern corner of the Ute 

Mountain Ute Indian Reservation in San Juan County, 

northwestern New Mexico (fig. 1 ). The Reservation 

boundary defines the southern and eastern limits of the 

study area. An irregular line from southwest to northeast 

Introduction 
that represents the outcrop of the coal-bearing Fruitland 

Formation defines the northwestern limit of the study 

area. 

The study area is most easily accessed from the 

south by a dirt road, which comes north about 9 mi from 

U.S. Highway 550 at the town of Kirtland, N. Mex. 

Recently, a heavy-duty haul road was constructed across 

the eastern half of the study area for use by large trucks 

to transport coal from the La Plata mine which is about 

8 mi northeast of the study area, to' the San Juan 

generating station, which is about 5 mi southwest of the 

study area (fig. 1 ). 

Previous Investigations 

Most of the coal beds in the study area were first 

described and mapped by Bauer and Reeside (1921). 

Hayes and Zapp (1955) used much of the data from that 

report in their investigations of coal in the Barker domeFruitland area. In a more recent study of coal resources 

in the Ute Mountain Ute Indian Reservation Shomaker 

and Holt (1973) used coal data from drill holes to 

supplement the outcrop data and thereby improved the 

overall reliability of the coal resource estimates. The 

I 

I ('. ,_r .__r--o, .l L 

_ _j 'V"l 

2 

3JO UTAH 

00' ARIZONA 

: _j l r·-----~ 

10 

i_ _ _j I 

UTE MOUNTAIN UTE 

INDIAN RESERVATION I 

L-, 

----1--------f---. - I ' .~ 

I

' I /;LA PLATA 

10 

•/ MINE 

, Study area 

L. ____ . -AJf.mlE:[ 

20 KILOMETERS 

I 

/ Kirtland 

I 

NORTHWEST EDGE OF 

SAN JUAN BASIN 

20 MILES 

Figure 1. Map showing Ute Mountain Ute Indian Reservation and 1 t" f d (shaded). oca 1on o stu y area 

Coal Resources, Ute Mountain Ute Indian Reservation, New Mexico 
geologic map of the Waterflow 7.5-minute quadrangle 

(Strobell and others, 1980) includes information on coal 

correlations within the study area. 

Western Coal Company drilled 17 coal exploratory 

holes during 1970 in an area termed the "prospecting 

permit area" by Shoemaker and Holt (1973). The area is 

located in the extreme southwestern corner of the study 

area in T. 31 N., R.15 W. (mapA on pl. 1). Unpublished 

products from the drilling project include nine maps, 

which show coal isopachs, overburden isopachs, and 

structure contours of the three major coal beds; geophysical and lithologic logs of the drill holes; and some 

coal-quality data. 

Method of Investigation 

Field work was done during the summers of 1986 

and 1987. The work consisted of field checking coaloutcrop locations described in previous reports, mapping 

the extent of the coal beds onto U.S. Geological Survey 

base maps at a scale of 1:24,000, examining and 

describing newly discovered coal outcrops, and measuring sections of the Fruitland Formation. 

In addition to information gathered in the field, 

data on the coal beds were obtained from 50 drill holes in 

and near the study area. The measurements of coal-bed 

thickness that were derived from interpretation of geophysical logs from coal test holes are considered to be 

accurate to within about 1 ft, and measurements from 

gamma-ray logs of oil and gas test wells are probably of 

similar accuracy. Thicknesses obtained only from the 

resistivity logs of oil and gas test wells may be less 

reliable. Table 1 is a list of drill holes that were used in 

the coal resource estimate, and figure 2 shows 

representative geophysical logs used to determine the 

thickness of coal beds in drill holes. 

All data from outcrops and drill holes were entered 

into the National Coal Resource Data System (NCRDS) 

format. The data were then contoured using Dynamic 

Graphics, Inc., Interactive Surface Modeling (ISM) 

program to produce isopach maps of coal and overburden and to produce structure contour maps. The ISM 

program was also used to calculate coal resources. Crosssection and coal-section diagrams were generated using 

the U.S. Geological Survey's Stratigraphic Analysis 

Techniques System (STRATS) program (Boger, 1986). 

Acknowledgments 

The Division of Energy and Mineral Resources of 

the U.S. Bureau of Indian Affairs provided funding for 

the project. Steve Graham, Realty Specialist, U.S. 

Bureau of Indian Affairs, Towaoc, Colo., helped locate 

well-log information on file in their office. Darwin Whiteman, Ute Mountain Ute Indian Tribe, Energy 

Administration, assisted in providing access to the study 

area. Edward Beaumont, consulting geologist, Albuquerque, N. Mex., was the geologist on the Western 

Coal Company drilling project within the prospecting 

permit area. He provided several copies of the original 

maps, geophysical logs, and lithologic logs for delivery to 

the Tribe and for use in this report. Drafting assistance 

from Nina Strange, U.S. Geological Survey volunteer, 

was especially appreciated. 

STRUC:TURE 

Th~~ Hogback monocline trends generally 

northeasterly through the center of the map area (mapA 

on pl. 1). Here the monocline is reflected in the small 

hogbacks that are formed by steeply dipping beds of the 

Pictured Cliffs Sandstone, sandstones of the Fruitland 

Formation, and the Farmington Sandstone Member of 

the Kirtland Shale (Hayes and Zapp, 1955). Strata along 

the Hogback monocline in this area dip 20-37° 

southeastward. Northwestward from where the Fruitland 

Formation crops out in the study area, the strata flatten 

gradually; southeastward they flatten abruptly to 1-2°. 

The structure contours drawn on the top of the Main coal 

bed in the study area (map B on pl. 1) show the variation 

in direction and dip of the strata basinward. 

STRAl"IGRAPHV OF FRUITLAND 

FORM~~TION 

Figure 3 shows the stratigraphy of Cretaceous and 

Tertiary rocks in the San Juan Basin in New Mexico and 

Colorado. The rocks discussed in this report belong to 

the coal-bearing Fruitland Formation of late Campanian 

age. The geologic map (map A on pl. 1) shows the 

distribution of the Menefee Formation, Cliff House 

Sandstone, Lewis Shale, Pictured Cliffs Sandstone, Fruitland Formation, members of the Kirtland Shale, and 

undiffere:ntiated Upper Cretaceous and Tertiary rocks in 

and near the study area. For descriptions of lithology, 

bedding characteristics, depositional environments, 

nature of formational contacts, and thickness of the rock 

units shown on map A on plate 1, see Hayes and Zapp 

(1955). Not shown on the geological map are surficial 

deposits, such as alluvium and slope wash. 

The Fruitland Formation, which reaches a 

maximum thickness of about 380 ft in the study area, 

consists of interbedded siltstone, shale, sandstone, coal, 

and a few thin beds of limestone. The sediments that 

formed the Fruitland Formation accumulated about 70 

Stratigraphy of Fruitland Formation 3 
Table 1. Drill holes in and near the Ute Mountain Ute Indian Reservation that were used in coal resource evaluation 

[Holes with prefJX U or 01 are coal exploratory holes; other holes are oil and gas test wells. Asterisks indicate holes used in resource calculations 

by Shomaker and Holt (1973). Sections in T. 31 N., Rs. 14 and 15 W., are projected] 

---------- Hole Location Approximate Total Company Well name No. Sec., T. N., R. w. surface depth 

elevation (feet) 

(feet) 

10031* 3 30 14 5,647 5,046 Albert C. Bruce Bryan No. 1. 

10039 5 30 14 5,582 5,811 do. Fed Pipkin 1. 

10040* 4 30 14 5,586 5,084 do. Richardson 1 No. 5. 

10184 36 31 15 5,598 4,291 Humble Oil & Refining Ute Tribe "B" No. 4. 

10222* 29 31 14 5,495 4,554 Standard Oil of Texas Ute Mountain Tribal 2-29 No. 15. 

10283* 30 31 14 5,511 4,472 Three States Natural Gas Tribal No. s. 

10284* 29 31 14 5,517 4,450 Standard Oil of Texas Ute Mountain Tribal 2-29 No. 6. 

10287 30 31 14 5,534 4,480 Three States Natural Gas Ute Mountain Tribal No. 6. 

13153* 30 31 14 5,558 4,500 do. Ute Mountain Tribal No. 7. 

13154 30 31 14 5,511 4,400 do. Tribal No. 9. 

13155* 30 31 14 5,473 4,516 do. Tribal No. 15. 

13156 31 31 14 5,509 4,580 do. Tribal No. 10. 

13157* 31 31 14 5,540 4,600 do. Tribal No. 11. 

13158* 31 31 14 5,550 4,600 do. Tribal No. 12. 

20666 5 30 14 5,429 846 Jerome P. McHugh Norton No. 1. 

20680* 35 31 14 5,626 1,293 do. No. 1 Foxtail. 

21604 36 31 14 5,685 6,455 El Paso Natural Gas Pinon Mesa No. 1. 

21608 25 31 14 5,616 6,300 do. Pinon Mesa No. 2. 

21613 23 31 14 5,712 5,590 do. Pinon Mesa No. 3. 

21638 35 31 15 5,425 4,600 Clinton Oil V.G. 35-1. 

21968 36 31 14 5. 711 6,394 El Paso Natural Gas Pinon Mesa A No. 2. 

21992 24 31 14 5,705 6,521 do. Pinon Mesa C No. 2. 

21993 25 31 14 5,688 6,440 do. Pinon Mesa B-2. 

21999 13 31 14 5,681 6,503 do. Pinon Mesa D No. 2. 

22377 1 30 14 5,877 6,550 Odessa Natural Little Fed 2. 

23286 35 31 14 5,632 6,275 El Paso Natural Gas Pinon Mesa A No. 3. 

60042 31 31 14 5,465 4,600 Three States Natural Gas Tribal No. 8. 

PMA1E 36 31 14 5,836 6,500 El Paso Natural Gas Pinon Mesa A No. 1E. 

PMA2E 36 31 14 5,655 6,300 do. Pinon Mesa A No. 2-E. 

PMA4 35 31 14 5,677 6,300 do. Pinon Mesa A No. 4. 

PMB1E 25 31 14 5,609 6,260 do. Pinon Mesa B No. 1E. 

PMB2E 25 31 14 5,641 6,310 do. Pinon Mesa B No. 2-E. 

PMC2E 24 31 14 5,723 6,522 do. Pinon Mesa c No. 2-E. 

U1* 35 31 15 5,420 200 Western Coal Unnamed. 

U2* 35 31 15 5,445 210 do. Do. 

U3* 25 31 15 5,450 200 do. Do. 

U4* 25 31 15 5,496 236 do. Do. 

US* 34 31 15 5,424 142 do. Do. 

U6* 35 31 15 5,393 242 do. Do. 

U7* 35 31 15 5,402 179 do. Do. 

U8* 35 31 15 5,455 240 do. Do. 

U9* 35 31 15 5,435 130 do. Do. 

U10* 35 31 15 5,452 212 do. Do. 

U11* 35 31 15 5,481 162 do. Do. 

U12* 25 31 15 5,459 181 do. Do. 

U13* 25 31 15 5,463 240 do. Do. 

011 3 30 15 5,499 95 do. Do. 

OlM 3 30 15 5,460 162 do. Do. 

OlP 2 30 15 5,407 198 do. Do. 

01T 2 30 15 5,397 300 do. Do. 

4 Coal Resources, Ute Mountain Ute Indian Reservation, New Mexico 
NATURAL GAMMA 

Increase~ 

DRILL HOLE 

01 p RESISTANCE c:::;:::::: 

3.5 

1.0 

TOTAL DEPTH 198 

DEPTH 

- 40 

- 60 

- 80 

-100 

-120 

-140 

Figure 2. Representative geophysical logs used to 

determine coal-bed thickness in drill holes. All values in 

feet. Coal shown as black unit in center column; 

thickness of coal shown to left of center column. 

million years ago (Manfrino, 1984) in swamps, lagoons, 

and stream channels on a broad, flat coastal plain. The 

Fruitland coals developed inland from and 

contemporaneously with the shoreline deposits of the 

Pictured Cliffs Sandstone. 

The contact of the Fruitland Formation with the 

underlying Pictured Cliffs Sandstone is conformable and 

sharp. In drill holes the contact is placed at the top of the 

massive sandstone below the lowermost coal of the 

Fruitland Formation; on the surface the contact is usually 

placed at the top of the highest Ophiomorpha-bearing 

sandstone (Fassett and Hinds, 1971). In the study area, 

the first major coal bed of the Fruitland either directly 

overlies or occurs within about 15 ft of the sandstone of 

the Pictured Cliffs. Therefore, for simplicity on the 

geologic map (map A on pl. 1), the contact between the 

Pictured Cliffs Sandstone and the Fruitland Formation is 

placed at the base of the lowest coal bed. The contact of 

the Fruitland Formation with the overlying continental 

deposits of Kirtland Shale is conformable, gradational, 

and variable. The contact is genera11y placed at the top of 

the highest prominent sandstone or coal bed of the 

Fruitland Formation. 

Sandstone of the Fruitland Formation is yeiiowish 

gray and light brownish gray, very fine to fine grained, 

and well sorted. Sandstone occurs in lenses a few inches 

thick and in lenticular beds as much as 30 ft thick. 

Common sedimentary structures in the sandstones 

include small- to medium-scale trough crossbedding, 

low-angle crossbedding, and ripple lamination, the last of 

which usually occurs toward the top of a sandstone unit. 

The sandstone is generally friable and weathers readily, 

but where it is more resistant, it forms the hogbacks that 

typify the scenery. Shale in the Fruitland Formation is 

commonly interbedded with thin lenses of medium-gray 

siltstone, brown and dark-gray carbonaceous shale, silty 

limestone, and sandstone. Very thin lenses of pink and 

grayish-orange claystone (altered volcanic ash) 

commonly occur as partings in the coal beds. Several coal 

beds are present and range in thickness from a few inches 

to 14 ft. Almost all the coal beds contain at least one 

parting. 

COAL DEPOSITS 

The distribution of the coal beds in the Fruitland 

Formation is shown in the generalized stratigraphic 

sections that accompany the geologic map (map A on pl. 

1). The areal distribution of the coal beds is shown on the 

geologic map and in the three cross sections (sections 

A-Con pl. 1). Figure 4 shows the location of these cross 

sections. 

Three economically important coal beds occur in 

the Fruitland Formation in this area. Table 2 compares 

the coal-bed nomenclature used in this report with that of 

previous reports. The Ute Canyon bed was named in this 

report for a small arroyo located along the Fruitland 

outcrop in the western part of the study area. The Main, 

Upper Main, and Ute Canyon coal beds correlate with 

coal beds designated as the lower split of the Main bed, 

upper split of the Main bed, and Upper bed, respectively, 

by Western Coal Company, based on the drilling done on 

the prospecting permit area. Strobell and others (1980) 

mapped what they termed theE and F coal beds in the 

extreme northeastern corner of the Waterflow 7.5-

minute quadrangle. Information from the coal 

exploratory drilling in the prospecting permit area 

indicates that the E and F beds are actually one 

continuous bed that correlates with the Ute Canyon bed. 

The C and B beds of Strobe11 and others (1980) are the 

Upper Main and Main beds, respectively, of this report. 

According to Hayes and Zapp (1955), the 79-ft-thick 

Carbonera bed south of Durango, Colo., had been 

mistakenly correlated by Bauer and Reeside (1921) with 

the Upper Main bed. The Upper Main bed is actuaiiy 

stratigraphically lower than the Carbonera bed. Because 

the int crtonguing relationship of the Fruitland 

Formation with the underlying Pictured Cliffs Sandstone 

was unknown at the time, Bauer and Reeside 

Coal Deposits 5 
~------------------- 240 KILOMETERS NEI (150 miles)---------------;-~------~= NEW MEXICO COLORADO _ ~~------------------SAN JUAN BASIN----------'-'-=--'-'--'=--'--'--f·---'-------~ 

SAN JUAN MTNS 

[ Durango • : 1 Pagosa 

A~~r<?::ingt~~/ ___ _§ ~ring_s 

: I I SAN I JUAN 

: I I I BASIN • 1 Cuba i I 

Jallup 

! Albuquerq~e 

METERS FEET 

EXPLANATION 

~ Nonmarine rocks 

.. Marine and coastal-barrier sandstone 

c=J Marine shale and siltstone 

Calcareous shale 

Time marker bed, e.g., bentonite, calcareous 

~----BLANCO GAS FIELD----~ 

Figure 3. Stratigraphic cross section showing Upper Cretaceous and Tertiary rocks from southwest to northeast across the 

San Juan Basin in New Mexico and Colorado. Cen., Cenomanian; Turon., Turonian; Con., Coniacian; Maastricht., 

Maastrichtian; Ss, Sandstone; Ls, Limestone; Sh, Shale; Mbr, Member. From Molenaar (1988). The nonmarine coal-bearing 

Fruitland Formation is crosshatched. 

erroneously based this correlation on the similar position 

of the two coal beds above the Pictured Cliffs Sandstone 

(Hayes and Zapp, 1955). The Local 1, Local 2, and 

Lower Ute Canyon beds were named specifically in this 

report, because they could not be correlated with beds in 

nearby areas. 

Coal-bed thicknesses have been determined in the 

study area by measurements on outcrops and in drill 

holes. Measurements on outcrops are shown on the 

measured coal sections on plate 1. Coal sections from 

Hayes and Zapp (1955) have the same section numbers 

in this report as in their report. Thick soil, slope wash, 

and talus cover at least part of the coal beds at many 

outcrop locations and allow only partial thickness 

measurements at those sites. Although thickness 

measurements of entire coal beds at outcrops may be less 

reliable than measurements from drilling (except in holes 

where the coal was cored), measurements of the number 

and thickness of partings within the coal are more 

reliable at outcrops. 

Thirty-four of the 50 drill holes that penetrate the 

Fruitland Formation in and near the southeast corner of 

the Ute Mountain Ute Indian Reservation were selected 

to illustrate coal-bed distribution and correlations (fig. 

4). Table 3lists the coals that were found in the drill holes 

used in this report and the thickness and depth from the 

surface of each coal bed. All the hole locations are 

plotted on the geologic map, and holes that were used to 

determine coal and overburden isopachs for the three 

major coal beds are shown on the maps of the individual 

beds. The point-location identifiers for all the oil and gas 

test wells, except those with the prefix PM, are the 

6 Coal Resources, Ute Mountain Ute Indian Reservation, New Mexico 
Table 2. Names used for coal beds in the study area 

[Leaders ( ---) indicate that the equivalent bed is not named) 

This 

report 

Strobell and 

others (1980) 

Western Coal 

Company, 1970 

Bauer and 

Reeside (1921) 

Ute Canyon 

Upper Main 

Main 

E and F 

c 

Upper bed 

B 

Upper split, Main bed 

Lower split, Main bed 

Carbonera. 

36° 

52' 

30" 

& Composite section Composed of coal section (Map A on plate 1) 

STLR40 .........••••••.....•... LR6, Z36B, and Z36A 

STLR7 .......••..•..•.....••.... LR8, LR9, LR1 0, and LR11 

STLR23 ........................ LR23 and Z31A 

Outcrop of Main coal bed 

/ - I / ' ' 

STLR7~. 21999~ I I I I : I , ' 

I PMC2E~ I I 

AI 21992~ 

/' 21613 : 

,./ N-S SECTION-/ 

,.// (SECTION A PLATE 1) i 

SW-NE SECTION :--/ 21993~ 

~~C_:!~~~!_02~~ ~TLR23 I I PMB2E~ 

21604~ 10184 

101'1 PMA4 21968 / I 

---- --ls£~i6~~c~~~:r£ '-)~~:__ ----~~1-~_: _j 

01M 

Figure 4. Map showing location of cross sections. 

American Petroleum Institute (API) numbers for wells 

listed in the Well History Control System (WHCS) of 

Petroleum Information, Inc. The PM holes are wells 

drilled in the southeast corner of the study area that were 

not listed in the WHCS. 

Description of Coal Beds 

The three most important coal beds occur in the 

lowermost part of the Fruitland Formation; the 

10039 10040 .-22377 

2 MILES 

3 KILOMETERS 

description of the individual beds begins with the lowest 

coal bed and continues stratigraphically upward. Two 

generalized stratigraphic sections that accompany the 

geologic map show the distribution of the coal beds in the 

southwestern part and in the northeastern part of the 

area (mapA on pl.l). The cross sections on sectionsA-C 

on plate 1 show that the coal beds and the rock intervals 

between the coal beds tend to vary in thickness and that 

some coal beds pinch out and split. Thickness variations 

in coal, interburden, and overburden related to the beds 

for which resources have been calculated are shown on 

maps C-G on plate 1. 

Coal Deposits 7 
Table 3. Thickness of coal and depth to correlated coal beds greater than 1.2 feet thick 

[All values are in feet. Leaders(···) indicate coal bed is not present. Where two numbers occur in thickness column, the first denotes net thickness 

of coal and the second denotes net thickness of partings) 

Hole Location Loca 1 2 Local 1 Ute Canyon Lower Ute Canyon Upper Main Main 

No. Sec. , T. N. , R. E. Thickness Depth to Thickness Depth to Th1ckness top top 

10031 3 30 14 

10039 5 30 14 8.0 

10040 4 30 14 6.0 10184 36 31 15 8.0/1.0 10222 29 31 14 9.0 

10283 30 31 14 9.0 

10284 29 31 14 8.0 

10287 30 31 14 9.0 13153 30 31 14 8.0 13154 30 31 14 8.0/1.0 

13155 30 31 14 6.0 13156 31 31 14 3.0 13157 31 31 14 8.0/2.0 13158 31 31 14 10.0/1.0 20666 5 30 14 4.0 

20680 35 31 14 3.0 21604 36 31 14 7.0 21608 25 31 14 4.0 1,134 6.0 21613 23 31 14 3.0 249 11.0/1.0 21638 35 31 15 

21968 36 31 14 6.0 21992 24 31 14 5.0 1,317 9.0/3.0 21993 25 31 14 5.0 1,230 9.0/1.0 21999 13 31 14 2.0 1 '137 6.0/4.0 1,220 13.0/3.0 22377 1 30 14 4.0 

23286 35 31 14 5.0 60042 31 31 14 6.0/3.0 P~4A1E 36 31 14 2.0 1,453 4.0 

PMA2E 36 31 14 2.0 1,169 4.0 PMA4 35 31 14 5.0/3.0 1,148 6.0 

PMB1E 25 31 14 3.0 1,096 6.0/2.0 PMB2E 25 31 14 2.0 1,227 6.0 PMC2E 24 31 14 3.0 1,267 8.0/2.0 1,369 14.0/2.0 U1 35 31 15 

U2 35 31 15 

U3 25 31 15 8.0/2.4 U4 25 31 15 11.5/0.8 us 34 31 15 

U6 35 31 15 6.4 U7 35 31 15 

u8 35 31 15 U9 35 31 15 

U10 35 31 15 5.3/0.4 U11 35 31 15 

U12 25 31 15 9.3/2.5 

U13 25 31 15 11. 7/0.8 01L 3 30 15 01M 3 30 15 2. 7 01P 2 30 15 5.0/0.8 OlT 2 30 15 6.4 

Main Bed 

The Main coal bed underlies the entire study area 

except locally in the north-central part of sec. 31, T. 31 

N., R. 14 W. The Main coal bed occurs directly on or 

within about 15 ft of the top of the Pictured Cliffs 

Sandstone. About 40 percent of the coal in the Main bed 

is under less than 500ft of overburden (map Con pl. 1). 

The thickness of the Main bed ranges from 1.1 ft at the 

outcrop in sees. 26 and 27, T. 31 N., R. 14 W., to 10.0 ft 

at drill hole PMC2E in sec. 24, T. 31. N, R. 14 W. The 

thickness averages about 5.0 ft over most of the area 

Depth to Th 1ckness Depth to Th 1 ckness Depth to Th 1ckness Depth to 

top top top top 

5.0/3.0 1,154 

831 

842 7.0 977 

421 4.0 503 4.0 520 

442 6.0 527 6.0 553 

270 5.0 355 6.0 379 

281 7.0 351 6.0 377 

283 5.0 365 6.0 387 

283 4.0 354 6.0 379 

221 8.0 286 5.0 308 

372 5 .o 455 5.0 478 

464 4.0 543 5.0 562 

432 5 .o 523 

402 5.0 482 4.0 501 

592 6.0 719 

1,054 5.0 1,161 

1,386 5.0 1,486 

1,243 6.0 1,346 

392 5.0 498 

6.0/5.0 201 5.0 229 

1,344 8.0 1,447 

1,467 4.0 1,548 

1,416 5.0 1,513 

1,361 9.0 1,440 

1,524 3.0 1,630 

1,162 3.0 1,266 

459 4.0 526 6 .o 545 

1, 531 5.0 1,626 

1,293 6.0 1,387 

1,253 6.0 1,359 

1,220 2.0 1,318 

1,334 3.0 1,354 5.0 1,441 

1,484 10.0/2.0 1,550 

7.6/6.6 82 4.0/0.5 112 

7.0/0.8 161 6.3/0.5 184 

66 6.0/1.0 136 3.8/0.3 157 

118 4.4/1.3 180 3.6/1.2 200 

6.9/0.7 90 6.0/1.3 111 

94 2.5 139 8.2/2.0 195 6.7/1.6 214 

6.2/1.0 139 5.8/1.1 159 

7.8/1.0 100 6.2/0.8 124 7 .6/0. 7 73 6.3/0. 7 96 

72 3.1 86 7.2/0.6 166 5.7/0.8 189 

1.9/1.2 42 7.2/0.5 104 5.3/0.4 126 

59 7.1/0.5 126 2.8/0.5 146 

136 7.6/0.2 198 

8.0/0.2 63 8.6 80 

23 8.0/0.2 132 7. 9 148 

50 7.1/0.4 163 3.5 178 

152 7.5/0.8 255 6.2/1.1 275 

but is greatest in the extreme northeastern and extreme 

southwestern corners of the study area. Because of 

limited information, the thickness of the Main bed is 

inferred in an area of several square miles in the central 

part of the study area. 

One or more partings occur in the Main coal bed at 

many outcrop locations and in the core samples from 

coal exploratory drill holes. It is likely that partings also 

occur in the Main bed where it is represented on the oil 

and gas well logs, but because of the poor resolution of 

these logs, the partings are not detectable. 

8 Coal Resources, Ute Mountain Ute Indian Reservation, New Mexrco 
Upper Main Bed 

The interval between the Main and Upper Main 

coal beds ranges in thickness from 3.5 ft at the outcrop in 

measured sections Z30 and Z32, sees. 26 and 27, T. 31 

N., R. 14 W., to more than 20ft near the center of sec. 30, 

T. 31 N., R. 14 W. Map D on plate 1 shows that the 

thickness of this interval generally decreases from 

southwest to northeast. 

The Upper Main bed is confined to the western 

half of the study area. Everywhere in this area the 

overburden is less than 1,000 ft thick (map£ on pl.1). In 

the subsurface, the Upper Main coal bed pinches out 

along a line that trends roughly northeast from the 

southwest quarter of sec. 33, T. 31 N., R. 14 W., to the 

northwest quarter of sec. 26 in the same township (map 

E on pl. 1). The Upper Main coal bed reaches a 

maximum thickness of 8.2 ft in the southwestern corner 

of sec. 35, T. 31 N., R. 15 W. In general the Upper Main 

bed increases in thickness from southeast to northwest 

and, near the outcrop, maintains an average thickness of 

about 7ft. 

At least one parting exists in the Upper Main bed 

at all but one measured-section location (coal section 

Z30, measured coal sections on pl. 1) and at all the coal 

exploratory drill-hole locations. This suggests that even 

though partings do not show up on logs from the oil and 

gas wells, partings are probably present. At drill hole U1 

in sec. 35, T. 31 N., R. 15 W., a parting increases to a 

thickness greater than the thickness of the coal above and 

below it. For resource calculations the thickness of the 

upper and lower split were combined. 

Ute Canyon and Lower Ute Canyon Beds 

The Ute Canyon coal bed is present throughout the 

study area and occurs from 45 ft to about 130ft above the 

Upper Main bed or above the Main where the Upper 

Main has pinched out (map F on pl. 1 ). The Ute Canyon 

bed ranges in thickness from 2.7 ft at drill hole 01M in the 

southwestern corner of the study area to 14.0 ft at drill 

hole PMC2E in the northeastern corner of the study area 

(map G on pl. 1). 

This coal bed also contains partings; the number of 

partings appears to increase northeastward as the total 

thickness of the coal bed increases (measured coal 

sections on pl. 1). In the area between drill holes 21993 

and PMB2E in the eastern part of the study area (section 

A on pl. 1), the Ute Canyon bed splits into two beds. The 

lower split, here called the Lower Ute Canyon bed, 

pinches out southward within about one-half mile. The 

Ute Canyon bed also splits into two beds between driii 

holes U3 and U11 (section B on pl. 1) and along the 

outcrop in the north-central part of sec. 35, T. 31 N., R. 

15 W. (map A on pl. 1 ). Here the upper split (Ute 

Canyon bed) thins to its mtmmum thickness on the 

Reservation. The interval between the Ute Canyon bed 

and the lower split (Lower Ute Canyon bed) increases 

rapidly from where the bed splits and then maintains a 

consistent thickness of about 35ft. 

At drill hole US (mapA and section Bon pl. 1) in 

sec. 35, T. 31 N., R. 15 W., thick sandstone units at the 

stratigraphic position of the Lower Ute Canyon coal bed 

indicate the existence of a paleochannel in this vicinity. 

The presence of a high-energy fluvial channel and the 

associated influx of overbank sand and silt inhibited the 

formation of peat in the Ute Canyon swamp. 

Local1 Bed 

A zone of thin coal beds, here termed the Local 1 

bed, was mapped along the outcrop from the 

northeastern part of the study area to within 1 mi of the 

southwestern corner. This bed, which occurs about 100ft 

above the Ute Canyon bed, is characterized on the 

outcrop by thin coal beds (average thickness about 1.5 

ft), separated by intervals of rock that are about the same 

thickness as the coals (measured coal sections on pl. 1). 

The Local 1 bed is assumed to be continuous in the area 

between measured section LR35 in sec. 30, T. 31 N., R. 

14 W., and measured section LR36 in sec. 25, T. 31 N., R. 

15 W. (map A on pl. 1), even though there is no 

indication of its existence in the oil and gas wells (mapA 

and section B on pl. 1). Here the coals of the Local 1 bed 

are probably too thin to be detected by the logging 

equipment. 

Local2 Bed 

A coal bed here named the Local 2 bed crops out 

for about three-quarters of a mile in the extreme 

northeastern corner of the study area (map A on pl. 1 ). 

The Local 2 bed pinches out in the subsurface less than 

a mile to the southeast of the outcrop, south of drill hole 

PMC2E (section A on pl. 1). This coal bed lies about 85 

ft above the Local1 bed and ranges in thickness from 2.0 

to 3.0 ft. 

Coal Quality 

The apparent rank of the coal in the Ute Canyon, 

Upper Main, and Main beds is high-volatile C 

bituminous. Seven samples from four core holes drilled 

by Western Coal Company show sulfur values that range 

from 0.81 to 1.25 percent, ash values that range from 8.08 

to 19.84 percent, and heat-of-combustion values that 

range from 9,443 to 11,689 Btu/lb on an as-received basis 

(table 4). Average values for coal quality of the Main, 

Upper Main, and Ute Canyon coal beds are shown in 

table 5. These values are within the range of values for 

Cretaceous coals of the Western United States (R.H. 

Affolter, oral commun., 1989). 

Coal Deposits 9 
Table 4. Analyses of coal in the Fruitland Formation from Western Coal Company core holes 

[All analyses, except heat-of-combustion and Hardgrove Grindability Index, are in percent. For each sample number, the analyses are reported first, 

as-received, and second, moisture-free. Analyses by Commercial Testing and Engineering Co. Table modified from Shomaker and Holt (1973). 

Leaders ( ---) indicate no data] 

Hole Location Sample Depth Proximate analysis Ultimate analysis Heat-of- Hardgrove 

No. Sec., T. N., R. w. No. interval Mo1sture Ash Sulfur combustion Grindability 

sampled (BTU/lb} Index 

(feet) 

Ute Canyon bed 

U4 25 31 15 72-4338 117.6-129.9 12.47 17.64 ().8R 9,670 44.2 

20.15 1.00 11,048 

Ul3 25 31 15 72-4337 136.1-150.2 10.44 19.84 .99 9,669 45.6 

22.15 1.11 10,796 

Upper Main bed 

U7 35 31 15 72-4259 139.5-146.7 9.16 8.08 1.14 11,689 39.1 

8.90 1.25 12,868 

U9 35 31 15 72-4336 73.0-81.3 12.57 14.29 1.09 10,193 41.8 

16.34 1.25 11,659 

U13 25 31 15 72-4335 197.9-205.7 11.02 11.83 .81 10,871 40.8 

13.29 .91 12,217 

Main bed 

U7 . 35 31 15 72-4?.60 158.9-165.8 13.21 18.66 1.25 9,443 40.4 

21.50 1.44 10,880 

U9 35 31 15 72-4334 95.7-102.7 8.55 18.04 .90 10,221 39.6 

19.73 .98 11,177 

Table 5. Average heat-of-combustion and moisture, ash, and sulfur content on an as-received basis, Hardgrove Grind ability 

Index, and apparent rank, by coal bed, of seven coal samples from the southeastern part of the Ute Mountain Ute Indian 

Reservation 

[The Parr formula (American Society for Testing and Materials, 1977) was used to calculate moist mineral-matter-free heating value and to 

determine coal rank] 

Coal bed Number Moisture Ash Sulfur 

of (percent) (percent) (percent) 

samples 

Ute Canyon 2 ll.46 18.74 0.94 

Upper Main 3 10.92 11.40 1.01 

Main 2 10.88 18.35 1.08 

Coal Resources 

Resource estimates were calculated for the Ute 

Canyon, Upper Main, and Main beds. The three major 

beds contain an estimated 215 million short tons of coal 

distributed in various categories as shown in table 6. An 

additional 37 million short tons are contained in the 

Heating value Moist mineral- Hardgrove Apparent 

( Btu/1 b) matter-free Grindability coal 

heat-of- Index rank 

combustion 

(Btu/lb) 

9,670 12' 143 44.9 High-volatile 

C bituminous. 

10,917 12,471 40.6 Do. 

9,832 12,285 40.0 Do. 

Local1, Local 2, and Lower Ute Canyon beds, and in 

other beds 1.2 ft thick or greater that could not be 

correlated within the study area. Table 7 shows estimated 

total coal resources of the Fruitland Formation, and map 

H on plate 1 shows the distribution of total coal thickness 

within the formation. Coal resources were not calculated 

for the Lower Ute Canyon, Local 1, and Local 2 as 

1 0 Coal Resources, Ute Mountain Ute Indian Reservation, New Mexico 
g 

!. 

i 

, 

0 

0 

= 0 

Table 6. Summary of estimated coal resources, by bed 

[In thousands of short tons. Leaders ( ---) indicate no coal for specific category. Tonnages may not total precisely because of rounding to three significant figures] 

Coal bed 

Ute Canyon 

Ute Canyon 

Upper Main 

Main 

Subtotal 

Ute Canyon 

Upper Main 

Main 

Subtotal 

Ute Canyon 

Upper t4ain 

Main 

Subtotal 

Upper Main 

Main 

Subtotal 

Total 

Overburden 0-200 feet 

Measured Indicated Inferred Total 

127 

8,000 

4,000 

668 

12,700 

3,060 

5,170 

5,940 

14,200 

9.72 

311 

708 

1,030 

11.4 

90.5 

102 

28,200 

323 

2,990 

109 

3,100 

1,900 

495 

661 

3,060 

369 

230 

599 

20.3 

20.3 

7,100 

554 

554 

554 

450 

11,500 

4,000 

777 

16,300 

4,960 

5,660 

6,600 

17,300 

9.72 

680 

938 

1,630 

11.4 

111 

122 

35,800 

Overburden 200-500 feet Overburden 500-1,000 feet Overburden >1,000 feet Grand 

total Measured Indicated Inferred Total Measured Indicated Inferred Total Measured Indicated Inferred Total 

104 

13,000 

766 

737 

14,500 

2,320 

6,000 

7,180 

15,500 

31.2 

156 

341 

528 

118 

133 

251 

30,900 

429 

10,600 

116 

10,700 

5,840 

4,520 

5,920 

16,300 

210 

713 

923 

In beds greater than 14 feet thick 

533 7.48 

In beds 7-14 feet thick 

2,700 

2,700 

26,300 

766 

853 

27,900 

1,990 

579 

2,570 

In beds 3.5-7 feet thick 

400 8,560 

24.1 10,500 

92.3 13,200 

516 32,300 

695 

2,440 

3,690 

6,820 

In beds 2.3-3.5 feet thick 

493 

13,000 

1,360 

14,400 

10,900 

895 

14,200 

26,000 

31.2 

366 

1,050 

0.927 130 

1,450 

186 1,840 

266 

453 

2,760 

4,730 

1,820 

1,820 

1,480 

1,890 

3,370 

--------------------- In beds 1.2-2.3 feet thick 

500 

16,800 

1,940 

18,700 

13,100 

3,340 

19,800 

36,200 

131 

2,030 

3,030 

5,190 

585 

8,140 

3,720 

11,900 

9,640 

10,600 

56.0 

3,220 

586 

3,810 

5,940 

7,410 

20,200 13,400 

387 

808 

1,200 

392 

1,460 

1,850 

251 

251 

0.449 

641 2,120 

11,400 66,000 

4,770 

4,310 7,880 

-----

15 '700 78,600 

15,800 42,400 

19,500 

18,000 57,600 

-----

33,800 120,000 

779 

2,270 

951 

3,080 

7,290 

0.449 3,050 11,300 

·-------------------------------------------------------------------------------------------

474 

237 

711 

29,100 

30.0 622 

370 

30.0 992 

3,250 63,200 

90.2 

921 

1,030 

90.2 1,950 

9,940 47,600 

70.6 992 

1,120 

70.6 2,110 

5,260 62,800 

145 13.4 

145 13.4 

34,000 19,100 251 

158 

1,620 

1,760 

158 3,380 

53,400 215,000 
Table 7. Estimated total coal resources of the Fruitland Formation as of July 1, 1987 

[In thousands of short tons. All beds 1.2 feet thick or greater were considered in resource estimate. Values rounded to three significant 

figures] 

Overburden Less than 200-500 feet 

thickness 200 feet 

Measured 30,000 26,400 

Indicated 11,700 33,100 

Inferred 11,700 17,200 --- Total 53,400 76,700 

individual beds for the following reasons: (1) The Lower 

Ute Canyon bed is generally too thin (less than 1.2 ft) to 

provide an appreciable resource, (2) the Local2 bed has 

a very limited distribution, and (3) the Local 1 bed 

contains partings that compose more than half of the 

total thickness of the bed. The estimates were obtained 

from information in this report and are current as of July 

1, 1987. 

Resources of the Ute Canyon, Upper Main, and 

Main coal beds were calculated for beds in five thickness 

categories according to U.S. Geological Survey standards 

for bituminous coal (Wood and others, 1983). The totals 

are summarized in table 8. 

Resources of the three major coal beds were also 

calculated according to reliability, or degree of geologic 

assurance, of the estimates. "Measured" coal is coal 

located within a ¥4-mi radius of a coal measurement in a 

drill hole or at an outcrop. "Indicated" coal is between V.. 

mi and 3.4 mi of a coal measurement; it extends Y2 mi 

beyond the limit of measured coal. "Inferred" coal is 

between V.. mi and 3 mi of a coal measurement; it extends 

2 Y4 mi beyond the limit of indicated coal. All the coal in 

the study area is within 3 mi of a measurement. 

500-1,000 feet Greater than Total 

1,000 feet 

7,400 41,500 105,000 

53,300 16,500 115,000 

3,200 32,1 no 

----

63,qoo 58,000 252,000 

Resources calculated for each degree of geologic 

assurance are summarized in table 9. 

Coal resource estimates were further divided into 

categories according to depth of the three major beds 

below the surface: 0-200 ft, 200-500 ft, 500-1,000 ft, and 

greater than 1,000 ft. The four overburden categories 

and estimates of coal for each category are listed in tables 

10 and 11. 

Isopach maps of overburden for the Main, Upper 

Main, and Ute Canyon coal beds are shown on maps 

C, E, and G, respectively, on plate 1. 

Potential for Surface Mining 

Shomaker and Holt (1973) determined that the 

prospecting permit area in the southwestern corner of 

the study area is suitable for surface mining. Based on the 

17 coal exploratory holes drilled in and near this area, an 

estimated 14.6 million short tons of coal are contained in 

the Ute Canyon, Upper Main, and Main beds. These 

beds have a combined maximum thickness of 20.5 ft and 

lie at depths between 20 and 200ft (Edward Beaumont, 

oral commun., 1986). 

Table 8. Estimated coal resources, by bed thickness 

[Ute Canyon, Upper Main, and Main coal beds only. >,greater than] 

Bed thickness, Estimated coal, in Percent of 

in feet thousands of short tons total 

1.2- 2.3 3,380 2 

2.3- 3.5 11,300 5 

3.5- 7.0 120,000 56 

7.0-14.0 78,600 36 

>14.0 2,120 1 

12 Coal Resources, Ute Mountain Ute Indian Reservation, New Mexico 
Table 9. Estimated coal resources, by degree of geologic assurance 

[Ute Canyon, Upper Main, and Main coal beds only] 

Degree of geologic 

assurance 

Measured 

Indicated 

Inferred 

Estimated coal, in 

thousands of short tons 

103,000 

103,000 

9,320 

Percent of 

total 

48 

48 

4 

Table 10. Estimated coal resources, by overburden thickness and bed thickness 

(Ute Canyon, Upper Main, and Main coal beds only. >,greater than; <,less than] 

Bed thickness, Estimated resources, in Percent of 

in feet thousands of short tons total 

Overburden less than 200 feet 

1.2- 2.3 122 <1 

2. 3- 3. 5 1,630 <1 

3.5- 7.0 17,300 8 

7.0-14.0 16,300 8 

>14 450 <1 

Overburden 200-500 feet 

1.2- 2.3 992 <1 

2. 3- 3. 5 1,450 <1 

3.5- 7.0 32,300 15 

7.0-14.0 27,900 13 

>14 533 <1 

Overburden 500-1,000 feet 

1.2- 2.3 2,110 1 

2. 3- 3.5 5,190 2 

3.5- 7.0 36,200 17 

7.0-14.0 18,700 8 

>14 500 <1 

Overburden greater than 1,000 feet 

1.2- 2.3 158 <1 

2. 3- 3. 5 3,050 1 

3.5- 7.0 33,800 16 

7.0-14.0 15,700 7 

>14 641 <1 

Coal Deposits 13 
Table 11. Estimated coal resources, by overburden thickness and degree of geologic 

assurance 

[ <, less than] 

Degree of geologic 

assurance 

Estimated resources, in 

thousands of short tons 

Percent of 

total 

Overburden less than 200 feet 

Measured ~8,200 13 

Indicated 7,100 3 

Inferred 554 <1 

Overburden 200-500 feet 

Measured 3o,qoo 14 

Indicated 29,100 13 

Inferred 3,250 1 

Overburden 500-1,000 feet 

Measured 9,940 7 

Indicated 47,600 22 

Inferred 5,260 2 

Overburden greater than 1,000 feet 

Measured 

Indicated 

Inferred 

From the eastern edge of the prospecting permit 

area eastward to a north-south line through the location 

of measured section Z26B in sec. 29, T. 31 N., R. 14 W., 

an estimated 20 million short tons of coal occur less than 

500 ft below the surface in the Main, Upper Main, and 

Ute Canyon coal beds, which here have a combined 

thickness of about 18 ft. Farther eastward from this 

location, more drilling is required to determine details on 

the occurrence, thickness, and correlation of the coals. 

It is important to keep in mind that the resource 

estimates represent the total amount of coal present in 

the study area and not necessarily the amount that is 

minable. Steep dips may adversely affect the suitability of 

certain areas for surface mining. Economic feasibility of 

mining of the coal in the Fruitland Formation in the 

southeastern corner of the Ute Mountain Ute Indian 

Reservation is improved by the presence and proximity of 

34,000 16 

19,100 9 

251 <1 

the recently constructed haul road that crosses the 

eastern half of the study area. 

Potential for Coal Bed Methane 

It is beyond the scope of this report to assess the 

resource potential of methane gas from coal beds within 

the Reservation. It should be noted, however, that 

methane gas has been produced in wells from coal beds 

of the Fruitland Formation in other parts of the San Juan 

Basin that have similar geologic settings. Methane 

resources of the San Juan Basin have been estimated and 

reported by several authors; Fassett (1988) summarized 

reports of these estimates. There is potential for recovery 

14 Coal Resources, Ute Mountain Ute Indian Reservation, New Mexico 
of methane from Fruitland Formation coal beds in the 

southeastern corner of the Reservation, but further 

investigation is necessary to estimate resources. Information in this report will be useful when beginning an 

assessment of the coal-bed methane potential. 

REFERENCES CITED 

American Society for Testing and Materials, 1977, Standard 

specifications for classification of coals by rank (ASTM 

designation D388--77): 1977 Annual book of ASTM 

standards, pt. 26, p. 214-218. 

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. 

Boger, L.W., Jr., 1986, Stratigraphic Analysis Techniques 

System (STRATS) user's manual: U.S. Geological 

Survey Open-File Report 86-102, 24 p. 

Condon, S.M., in press, Geologic and structure contour map of 

the Ute Mountain Ute Indian Reservation, southwest 

Colorado and northwest New Mexico: U.S. Geological 

Survey Miscellaneous Investigations Map 1-2083. 

Fassett, J.E., 1988, Geometry and depositional environment of 

Fruitland Formation coal beds, San Juan basin, New 

Mexico and Colorado-Anatomy of a giant coal-bed 

methane deposit, in Fassett, J.E., ed., Geology and 

coal-bed methane resources of the northern San Juan 

basin, Colorado and New Mexico: Rocky Mountain 

Association of Geologists Guidebook, p. 2338. 

1:r U.S. GOVERNMENT PRINTING OFFICE: 1991-573-049126,029 REGION NO.8 

Fassett, J.E., and Hinds, J.S., 1971, Geology and fuel resources 

of the Fruitland Formation and Kirtland Shale of the San 

Juan Basin, New Mexico and Colorado: U.S. Geological 

Survey Professional Paper 676, 76 p. 

Hayes, P.T., and Zapp, A.D., 1955, Geology and fuel resources 

of the Upper Cretaceous rocks of the Barker domeFruitland area, San Juan County, New Mexico: U.S. 

Geological Survey Oil and Gas Investigations Map OM144, scale 1:62,500. 

Manfrino, Carrie, 1984, Stratigraphy and palynology of the 

upper Lewis Shale, Pictured Cliffs Sandstone, and lower 

Fruitland Formation (Upper Cretaceous) near Durango, 

Colorado: Mountain Geologist, v. 21, no. 4, p. 115-132. 

Molenaar, C.M., 1988, Stratigraphic cross section showing 

Upper Cretaceous rocks across the San Juan basin, New 

Mexico and Colorado, in Fassett, J .E., ed., Geology and 

coal-bed methane resources of the northern San Juan 

basin, Colorado and New Mexico: Rocky Mountain 

Association of Geologists Guidebook, p. 21. 

Shomaker, J.W., and Holt, R.D., 1973, Coal resources of 

Southern Ute and Ute Mountain Ute Indian 

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