GEOLOGICAL SURVEY CIRCULAR 258 

COAL RESOURCES OF 

COLORADO 

A Progress Report, January 1, 1953 

UNITED STATES DEPARTMENT OF THE INTERIOR 

.Douglas McKay, Secretary 

GEOLOGICAL SURVEY 

W. E. Wrather, Director 

GEOLOGICAL SURVEY CIRCULAR 258 

COAL RESOURCES OF COLORADO 

A Progress Report, January 1, 1953 

By Frank D. Spencer and Margaret I. Erwin 

Washington, D. C., 1953 

Free on application to the Geological Survey, Washington 25, D. C.· 

COAL RESOURCES OF COLORADO 

A Progress Report, January 1, 1953 

By Frank D. Spencer and Margaret I. Erwin 

CONTENTS 

Page 

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

Summary...................................... 2 

Classification of reserves. . . . . . . . . . . . . . . . . . . . . . 2 

Rank of coal-. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Methods of preparing reserve estimates . . . . . . . . . 5 

Comparison of past and present estimates . . . . . . . 5 

Coal fields of Colorado. . . . . . . . . . . . . . . . . . . . . . . . . 7 

Yampa field. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

Uinta region . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

Danforth Hills field. . . . . . . . . . . . . . . . . . 7 

Lower White River field......... . . . . . 9 

Book Cliffs field. . . . . . . . . . . . . . . . . . . . . 9 

Grand Mesa field . . . . . . . . . . • . . . . . . . . . 9 

Somerset field . . . . . . . . . . . . . . . . . . . . . . 9 

Crested Butte field . . . . . . . . . . . . . . . . . . 9 

Carbondale field. . . . . . . . . . . . . . . . . . . . . 9 

Grand Hogback field . . . . . . . . . . . . . . . . . 9 

Page 

Coal fields of Colorado--Continued 

Tongue Mesa field. . . . . . . . . . . . . . . . . . . . . . . . 9 

San Juan River region . . . . . . . . . . . . . . . . . . . . 9 

Durango and adjacent fields . . . . . . . . . . 10 

Coal-bearing areas in Montrose 

and Montezuma Counties . . . . . . . . . . . 10 

Pagosa field ............. _. . . . . . . . . . . 10 

Raton Mesa region . . . . . . . . . . . . . . . . . . . . . . . 10 

Canon City field. . . . . . . . . . . . . . . . . . . . . . . . . . 10 

South Park field. . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Denver region . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

North Park field . . . . . . . . . . . . . . . . . . . . .. . . . . 11 

History of coal production . . . . . . . . . . . . . . . . . . . . . 11 

Conclusions . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . 11 

Bibliography. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

Unpublished reports. . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

ILLUSTRATIONS 

Page 

Plate 1. Map of Colorado showing coal-bearing regions and fields ............................. Inside back cover 

Figure 1. Chart showing tentative correlations of Cretaceous and Tertiary rocks in Colorado................. 8 

Table 1. 

2. 

3. 

4. 

5. 

6. 

TABLES 

Page 

Original coal reserves of Colorado, by fields, under less than 3, 000 feet overburden. 

(In millions of short tons) ...... ·.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Original coal reserves of Colorado, by counties, under less than 3, 000 feet overburden. 

(In millions of short tons) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

Classification of coals by rank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

Comparison of past and present estimates of Colorado coal reserves. 

(In millions of short tons) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . 6 

Coal produced in Colorado from 1864-86 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Coal produced in Colorado from 1887 to January 1, 1952, by counties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

INTRODUCTION 

This report is preliminary to a more ¢etailed 

reappraisal of the coal resources of Colorado now in 

progress. It is based, for the most part, on studies 

of published and unpublished reports in the files of 

the United States Geological Survey. Although the 

most comprehensive that can be prepared with the 

included in this report should be considered 

provisional because information on the extent and 

thickness of coal in many parts of the State is 

meager or lacking. At the present time, however, 

the Geological Survey is investigating several coalbearing areas in Colorado, and the results of 

these investigations will aid in providing more accurate data on which to base the planned revision of 

data immediately available, the coal reserve estimates the present estimate. 

1 
SUM1v1ARY 

The gross value of the coal produced annually 

in Colorado ranks second among the many valuable 

mineral products of the State, exceeded only by 

petroleum and petroleum products. Although coal 

production in the State has decreased in recent 

years, interest in coal reserves has increased 

because of the potential future needs for coking 

coal and for coal of lower ranks suitable for 

the manufacture of synthetic liquid fuels. 

The original coal reserves of Colorado are 

estimated to be 100, 408 million tons, of which 

9, 437 million tons is subbituminous coal, 90,258 

million tons is bituminous coal, and 713 million 

tons is semianthracite or anthracite. (See tables 

1 and 2.) Although coal-bearing rocks underlie 

about 25,400 square miles or 24 percent of the 

total area of the State, most of these rocks 

occur in intermontane structural basins, and little 

is known about the occurrence of coal in the 

central parts of these basins. Large areas in 

the State such as the Denver, Green River, Unita, 

and San Juan River regions, are believed to be 

underlain by coal throughout their entire area, 

but only the marginal areas were included in 

preparing the present estimate. 

The data used to compile the present 

estimate were restricted for the most part to 

mapped and explored areas within six miles, or 

less, of the coal outcrops. Thus restricted, the 

area of coal-bearing rocks considered in preparing 

this report totaled only 5, 277 square miles, or 

20 percent of the total probable coal-bearing 

area in the State. (See pl. 1.) This smaller area, 

however, includes all coal that is immediately 

accessible. 

Although most of the coal is in thicker 

beds, the minimum thickness of beds included 

in the estimate is 14 inches for bituminous coal 

and anthracite, and 30 inches for subbituminous 

coal. The maximum overburden on the coal included in the estimate is 3, 000 feet, although 

most of the reserves lie at depths much less 

than 3, 000 feet. 

CLASSIFICATION OF RESERVES 

The estimates given in tables 1 and 2 are 

for original reserves in the ground before mining 

began. They include coal formerly present in 

mined-out areas; coal in the narrow weathered 

zone at the outcrop; and coal underlying rai.lways, 

roads, and towns. The calculation of original 

reserves is both desi.rable and practicable for it 

gives a relatively stable figure on which to base 

estimates of t>emaining and recoverable reserves, 

which change with production and with changes in 

mining methods. Remaining and recoverable 

reserves as of any given time can be ascertained 

2 

more readily if the records of original reserves 

and the amount of coal mined and lost in 

mining are kept separately. 

The total recorded production of coal in 

Colorado from the beginning of mining to 

January 1, 1952, is 479 million tons. In addition 

to the . coal produced, an equal amount, more or 

less, is left underground, or otherwise lost in 

mining. On this basis an amount equal to twice 

that of the coal production shown in table 6 

(958 million tons), has been mined and lost in 

mining in the State. This figure, subtracted 

from the total original reserves of 100, 408 million tons, leaves remaining reserves on January 1, 

1952, of 99,450 million tons. 

Assuming that mining losses in the future 

will remain about equal to actual production, 

the recoverable reserves as of January 1, 1952, 

are estimated as half the remaining reserves, 

or approximately 50, 000 million tons. 

Rank of coal 

Coal is classified by rank according to 

the percentage of fixed carbon and the Btu content. The rank is determined according to the 

standard specifications of the American Society 

for Testing Materials, which are reproduced as 

table 3. 

The greatest part of the reserves in 

Colorado, 90, 258 million tons, or 90 percent 

of the total remaining reserves, is of bituminous 

rank. Most of this coal is of high-volatile C 

bituminous rank; the remainder ranges from highvolatile B to low-volatile bituminous rank. It is 

present in the Yampa, South Park, and Canon 

City fields and the Uinta, San Juan River, and 

Raton Mesa regions. The next larger part, 

9, 437 million tons, or 9 percent of the total 

reserves, is of subbituminous rank. The subbituminous coal ranges from subbituminous C to 

A. It is present in the coal fields of the Denver 

region and in the North Park, Yampa, and 

Tongue Mesa fields. The smallest part, 713 million tons, or 1 percent of the total reserve is 

semianthracite or anthracite in rank. It is 

present in the Crested Butte field of the Uinta 

region. A relatively small tonnage of semianthracite and anthracite in the Routt County 

part of the Yampa field is included in the tables 

with the bituminous coal. 

Although coking coal was not segregated in the 

tables, it is present in five areas in Colorado: the 

Trinidad, Durango, Crested Butte, Somerset, and 

Carbondale fields. The C:rested Butte field, together 

with the adjacent Somerset and Carbondale fields in 

Gunnison, Delta, and Pitkin Counties, and the Trinidad 

field in Las Animas and Huerfano Counties constitute the 

second and third largest coke-producing areas in the West, 
Table 1.--0riginal coal reserves of Colorado, by fields, under less than 3,000 feet overburden 

(In millions of short tons) 

Rank of coal Region 

Region or Square Sub- Bituminous Semianthracite or field 

field miles bituminous or anthracite total 

Denver.---------------------------- 535 3,662 --- --- 3,662 

Canon City------------------------ 35. --- 466 --- 466 

Raton Mesa------------------------ 1,023 --- 12,167 --- 12,167 

North Park------------------T----- 60 2,074 --- --- 2,074 

Yampa----------------------------- 793 3,136 22,405 --- 25,541 

Uinta----------------------------- 2,510 --- 51,797 713 52,510 

So~th Park------------------------ 3 --- 20 --- 20 

Tongue Mesa----------------------- 32 537 --- --- 537 

San Juan-------------------------- 286 28 3,403 --- 3,431 

Total 5,277 9,437 90,258 713 100,408 

Table 2.--0riginal coal reserves of Colorado,by counties, under less than 3,000 feet overburden 

County 

Adams-----------------------------

Arapahoe--------------------------

Archuleta-------------------------

Boulder---------------------------

Delta-----------------------------

Douglas---------------------------

Elbert----------------------------

El Paso---------------------------

Fremont---------------------------

Garfield--------------------------

Gunnison--------------------------

Huerfano--------------------------

Jackson-------------------~----·--

Jefferson---~---------------------

La Plata--------------------------

Larimer---------------------------

Las Animas------------------------

Mesa------------------------------

Moffat----------------------------

Montezuma-------------------------

Montrose--------------------------

Ouray-----------------------------

Park------------------------------

Pitkin----------------------------

Rio Blanco------------------------ Routt----------~-----------------­

Weld------------------------------

Total 

1 Includes some coking coal. 

(In millions of short tons) 

Square Submiles bituminous 

24 

4 

114 

63 

225 

3 

28 

67 

35 

325 

419 

273 

60 

113 

139 

18 

750 

395 

640 

7 

40 

7 

3 

32 

865 

413 

215 

5,277 

3 

238 

28 

28 

425 

40 

205 

396 

144 

2,074 

1,040 

98 

1,711 

287 

106 

1,425 

1,192 

.9,437 

Rank of coal 

Bituminous Semianthracite 

or anthracite 

County 

total 

412 

4,315 

466 

8,059 1 10,194 

1,270 

1 2,855 

1 10,897 

4,470 

22,014 

15 

121 

20 1 830 

17,223 

7,097 

90,258 

238 

28 

440 

425 

4,315 

40 

205 

396 

466 

8,059 

713 11,051 

1,270 

2,074 

1,040 

2,855 

98 

10,897 

4,470 

23,725 

15 

408 

106 

20 

830 

17,223 

8,522 

1,192 

713 100,408 
Legend:· F.C. - Fixed Carbon. V.M.- Volatile Matter. Btu. = British thermal units. 

Class I anuts o Faxe arbon or Group Requisite Physical Btu. Mineral-Matter-Free 

Basis Properties : 

L" • f • d C 

1. Meta-anthracite ................. Dry F .C .• 98 per cent or more (Dry V.M., 2 per c~t or less) 

~. Anthracite ...................... Dry F.C., 92 per cent or more 

I. Anthracitic 

and less than 98 per cent 

(Dry V.M., 8 per cent or less 

and more than 2 per cent) 

3. Semianthracite ........... ; ...... Dry F.C., 86 per cent or more N onagglomerating b 

and less tlian 92 per cent 

(Dry V.M., 14 per cent or less and more than 8 per cent) 

1. Low volatile bituminous coal .... Dry F .C., 78 per cent or more and less than 86 per cent 

(Dry V.M., 22 per cent or less and more than 14 per cent) I 

2. Medium volatile bituminous coal. Dry F.C., 69 per cent or more and less tlian 78 per cent 

(Dry V.M., 31 per cent or less and more than 22 per 

II. Bituminousd cent) 

3. High volatile A bituminous coal. Dry F.C.,less than 69 per cent1 (Dry V.M.,more than 31 per 1 cent); and moistc Btu., 

14,000' or more 

4. High volatile B bituminous coal. .1\loistc Btu., 13,()(;J or more and less than 14,000C 

! 

5. High volatile C bituminous coal. Moist Btu., 11,000 or more and less than 13,00C1' 

Efther agglomerating o non weathering/ 

1. Subbituminous A coal. .......... Moist Btu., 11,000 or more Both weathering an d 

and less than 13,oooe nonagglomerating 

III. Subbituminous 2. Subbituminous B coal. .......... Moist Btu., 9500 or more and1 

less than 11 ,000' I 

3. Subbituminous C coal. .......... Moist Btu., 8300 or more and! 

less than 95()04' ! -

IV. Ligni tic I 1. Lignite ......................... Moist Btu., less than 8300 Consolidated 

2. Brown coal ..................... Moist Btu., less than 8300 Unconsolidated 

--

n, This classification does not include a few coals which have unusual physical and chemical properties and which come within the limits of fixed carbon or Btu. of the high-volatile bituminous and subbituminous ranks. All of these coals 

either contain less than 48 per cent dry, mineral-matter-free fixed carbon or have more than 15,500 moist, mineral-matterfree Btu. 

b If agglomerating, classify in low-volatile group of the bituminous class. c Moist Btu. refers to coal containing its natural bed moisture but ~ot including visible water on the surface of the 

coal. 

d It is recognized that the-:-e may be noncaking varieties in each group of the bituminous class. e Coals having 69 per cent or more fixed carbon on the dry, mineral-matter-free basis shall be classified according to 

fiull carbon, regardless of Btu. f There are three varieties of coal in the high-volatile C bituminous coal group, namely, Variety 1, agglomerating andnonweathering; VariPi;Y 2. agglom,~rating and weathering; Variety 3, nonagglomerating and nonweathering. 

Table 3. CLASSIFICATION OF COALS BY RANK 

4 
exceeded only by the Sunnyside-Castlegate field 

in Utah (Berryhill, 1951, p. 13). 

METHODS OF PREPARING 

RESERVE ESTIMATES 

The reserves shown in this report represent for the most part a compilation of estimates 

made by many authors at various times in the 

past. Some authors estimated reserves by individual coal beds; others used an average total 

thickness of several ·beds; some used a depth 

figure of 3; 000 feet as the basis for the boundary of the reserve areas, and others used 

stipulated distances behind the outcrop of the 

coal beds. Few authors classified the individual 

beds according to thickness or overburden, and 

none separated the res-=rves into measured, 

indicated, and inferred categories according to 

present practice. 

Because of the preliminary nature of this 

report, and because sufficient data are lacking in 

some of the fields, reserve tonnages were not 

broken down into the accepted categories of 

measured, indicated, and inferred reserves, nor 

the accepted categories of thickness and overburden. In a few of the coal fields the estimates 

used herein are those calculated by the earlier 

authors. In most fields, however, the earlier 

estimates were modified to accord with the plan 

of presentation selected for this preliminary 

report. 

The m1mmum thickness of coal included 

in the estimates of reserves was 14 inches for 

anthracite, semianthracite, and bituminous coal, 

and 30 inches for subbituminous coal. Partings 

more than three-~ighths of an inch thick were 

excluded from the thickness of the bed and no 

tonnages were included in the estimate for coal 

more than 3, 000 feet below the surface. 

The following weights of coal per acre -foot 

were used in calculating reserves: anthracite and 

semianthracite, 2, 000 short tons; bituminous coal, 

1, 800 short tons; and subbituminous coal~ 

1, 770 short tons. 

A more detailed description of the methods 

used in preparing the reserve estimates for each 

individual field is included in the section Coal 

fields of Colorado. 

COMPARISON OF PAST AND 

PRESENT ESTIMATES 

Previous estimates of the coal resource.s 

of Colorado were made by Campbell (1913, p. 537) 

and Vanderwilt (1947, pp. 266-276). (See table 

4. ) In 1913, Campbell estimated the original 

reserves of coal in the State to be 317, 996 million 

5 

tons, contained in an area of 14,341 square 

miles. A revision of this estimate, made in 

1947 by Vanderwilt, decreased the tonna.ge of 

original reserves to 174, 208 million tons, or 

approximately one-half of Campbell's estimate. 

The area contained in Vanderwilt's report is 

20,295 square miles. Although entire basin areas, 

such as the Denver and Uinta regions, and the 

South Park field were considered in the Vanderwilt 

estimate, the reserves presumably were calculated for a much smaller area. 

In this provisional report the original 

reserves are estimated to be 100,408 million 

tons, contained in an area of 5, 277 square miles 

(tables 1, 2, and 4). As compared with the two 

previous estimates, the areal extent as well as 

the reserve tonnages were cut down considerably 

in areas such as the Denver and San Juan 

River regions, and the Yampa field. 

In the Denver region, Campbell calculated 

coal reserves for an area of 5, 380 square miles; 

in the present report reserves are calculated 

for an area of only 535 square miles. Although 

the probable coal-bearing land of this region 

comprises about 7, 600 square. miles, mining 

operations and data pertaining to coal outcrops 

in the larger area indicate that the beds lack 

persistency in thickness and continuity. 

Both the reserve tonnage and coal acreage 

for the San Juan River region are much smaller 

than those given by Campbell (table 4), because 

recent field work in parts of this region indicates that not only are the coal· beds lenticular, 

but the areal extent of the coal lying at depths 

of less than 3, 000 feet is much smaller than 

had been supposed. 

Campbell ( 1913) calculated reserves for 

an area of 3, 130 square miles in the Yampa 

field, as compared to 793 square miles in the 

present report. Recent field investigations, 

however, have proven that in a very large area 

in the northern part of the field in Routt 

County, the coal of the lower and middle coal 

groups of the Mesaverde group occurs at depths 

of more than 3, 000 feet and the coals of the 

Lance and Fort Union formations are sporadic. 

Because of this, reserves were estimated for 

only short distances from points of observation. 

In many of the fields and regions throughout the State, the greater tonnages and areas 

shown in the earlier reports are due to the 

inclusion by Campbell and Vanderwilt of large 

areas of coal-bearing rock for which data as 

to the thickness and extent of beds are not 

available. No estimates of reserves in such 

areas are included in this report, although a 

large part of them may contain coal, which 

subsequent explorations may discover. 
rn 

Table 4.--Comparison of past and present estimates of Colorado coal reserves, in millions of short tons 

Adapted from Campbell 

(1913) 

Region or field 

Denver------------------------------------~ 

Canon City---------------------------------

Raton Mesa---------------------------------

North Park-~------------------------------­

Yampa--------------------------------------

Uinta--------------------------------------

South Park---------------------------------

Tongue Mesa--------------------------------

San Juan-----------------------------------

Total 

1 Includes whole basin area; reserves presumably calculated for smaller area. 2 Includes .coal under more than 3,000 feet overburden. 

Square 

miles 

5,380 

40 

1,035 

57 

3,130 

2,780 

3 

40 

1,876 

14,341 

Tons 

40,018 

1,028 

24,473" 

2,854 

135,607 

84,101 

20 

929 

28,965 

317,995 

Adapted from Vanderwilt 

(1947) 

Square 

miles 

1 7,600 

40 

1,035 

500 

3,100 1 6,000 

1 8o 

40 

1,900 

20,295 

Tons 

14,000 

900 

22,000 

2 450 

40,000 

75,000 

18 

840 

21,000 

174,208 

This report 

(1952) 

Squ~re 

miles 

535 

35 

1,023 

60 

793 

2,510 

3 

32 

286 

5,277 

Tons 

3,662 

466 

12,167 

2,074 

25,541 

52,510 

20 

537 

3,431 

100,408 
COAL FIELDS OF COLORADO 

As a result of the structural disturbances and 

the igneous activity that accompanied and followed the 

uplift of the Rocky Mountains, coal beds occur in almost every conceivable attitude and physiographic 

environment in Colorado. The coals also differ widely 

in rank, ranging from subbituminous and bituminous 

coal to semianthracite and anthracite. The distribution 

of the numerous coal fields in Colorado, classified 

according to the rank of the coal, is shown in plate 1. 

The coal-bearing rocks in these fields underlie 

about 25, 400 square miles, or 24 percent of the total 

area of the State. Of this area, only 5, 277 square miles, 

or about 5 percent of the total area of the State is 

immediately accessible. This results from the fact 

that most of the coal fields are in intermontane structural basins in which the coal-bearing rocks crop out 

around the edges and dip towards the centers of the 

basins. The coal-bearing rocks are thus more readily 

accessible only in narrow bands around the edges of 

the basins, and most exploration and development has 

taken place in these bands. Coal probably occurs at 

depth in the centers of the structural basins, but the 

thickness and distribution of the beds can only be 

surmised. The restriction of reserve studies to the 

more accessible edges of the basins, where mining 

will be concentrated in the immediate future and where 

information as to the thickness and extent of the beds 

has been, or can be ascertained, is, therefore, both 

desirable and practicable. 

The coal-bearing formations in the State are of 

Late Cretaceous and early Tertiary age. These formations beginning with the oldest, are as follows: the 

Dakota sandstone, Mesaverde group, Fruitland, Lance, 

Laramie, Vermejo, Animas, Raton, Fort Union, Denver, 

and Coalmont formations. Except for the Coalmont 

formation, which is of Eocene age, the stratigraphic 

position of these formations is shown in figure 1. 

Yampa field 

The Yampa field is in northwestern Colorado and 

includes parts of Moffat, Routt, and Rio Blanco Counties. 

The field lies in a broad syncline that trends southeastward from Wyoming through this part of Colorado. 

The coal-bearing rocks in the east-central part of the 

field are strongly folded and faulted, and locally are 

cut by igneous intrusives, which have helped to develop 

high-rank coals. 

Anthracite, semianthracite, bituminous coal and 

subbituminous coal are found in the field. Although 

the largest part of the reserves occur in the Mesaverde 

group of the Late Cretaceous age, most of the lower 

rank coals occur in the Lance and Fort Union formations of the Late Cretaceous and Paleocene age. 

In the east'ern part of the field, small tonnages 

of anthracite are included with the reserves of bituminous coal (tables 1 and 2) because it is present only 

locally near sills of basalt that have intruded the coalbearing rocks, and geologic information is not sufficient to permit an accurate delineation of these small 

areas. 

7 

The reserves in the eastern part of the field were 

obtained from a recent report on the field by Bass 

(in preparation). The coal reserves given in his report were estimated, by Spencer, separately for each 

bed and were divided into the three thickness categories; 

three depths of overburden zones, based on maximum 

cover of 1, 000, 2, 000, and 3, 000 feet; and into measured, 

indicated, and inferred reserves. 

The reserves in the western part of the field 

were obtained from a report by Hancock (1925, p. 53), 

who based his estimate on an average total thickness 

of coal in each group of coal beds in the Iles and 

Williams Fork formations of the Mesaverde group. 

Hancock drew outcrop lines 11 at a horizon representing 

the center or weight 11 of each coal group and calculated 

reserves by townships to a depth of 3, 000 feet. His 

tonnage figures are included in the tables of this report, but the reserves for the upper beds are transferred from bituminous to subbituminous rank in order 

to conform with the more recent classification of coal 

used by the American Society for Testing Materials. 

Uinta region 

The Uinta region occupies the Colorado portion 

of the Uinta Basin which is a broad structural depression,extending from the middle of Gunnison County, 

Colorado, northwestward into central Utah. The coalbearing rocks form a band nearly encircling the region. 

The band is extremely narrow along much of the eastern 

margin of the region because there the rocks dip steeply 

southwestward. The data available, however, suggest 

(1) that the steep dips prevail only a very short distance 

southwest of the outcrop, and (2) that, except for the 

rim area, gentle dips probably prevail throughout most 

of the Uinta region. Deep wells, out in the basin, 

suggest that in large areas the depth to the coals of 

the Mesaverde group exceeds two miles. Large folds 

in the northeastern and northwestern parts of the region 

cause the outcrop band of coal-bearing rocks here to 

be relatively broad. The band is of medium width on 

the southwestern margin of the region, for here the 

rocks dip gently northeastward. 

The coal of the Uinta region occurs in several 

zones in the Mesaverde formation of Late Cretaceous 

age. Individual beds range from less than 3 to more 

than 20 feet in thickness. The region is divided into 

eight coal fields: the Danforth Hills, Lower White River, 

Book Cliffs, Grand Mesa, Somerset, Crested Butte, 

Carbondale, and Grand Hogback fields. 

Igneous intrusions and extrusions have greatly 

disturbed the southeastern end of the region and have 

markedly affected the rank of the coal. The Crested 

Butte field in this area contains large reserves of 

anthracite and semianthracite. This field together with 

the adjacent Somerset and Carbondale fields constitute 

the second largest coke-producing area in the West. 

Danforth Hills -field. -The Danforth Hills field 

in the northern part of the region includes parts of 

Moffat and Rio Blanco Counties. The coal is of bituminous rank and occurs in the Williams Fork formation of the Mesaverde group. The field contains 3 to 

10 workable coal beds ranging from 3 to 18 feet in thickness. 
..... 

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a..u 

1-----

CD 

c 

CD 

u 

0 

~ 

I 

OCD 

c-c 

=cu ou 

CD 

c 

Q) 

0 

0 

w 

1----

Southeastern. 

Colorado 

Ogallala fm. 

Huerfano fm. 

Cucharo rm. 

Poison Canyon 

fm. 

Rata~ fm. 

Northeast-em 

Colorado 

Ogallala f'm. 

-

Arikaree fm. 

White 

River Brule clay 

group Chadron fm. 

,.. 

De.nver f'm. 

Northwestern 

Colorado 

1----? 

Browns Park 

fm. 

Bishop congl. 

Uint-a fm. 

Bridger fm. 

Central 

Western Colorado 

Bridger fm. 

- Green River Green River 

fm. fm. 

Southwest-ern 

Colorado 

Potosi 

volcanic 

ser'les 

- American Flat lotite 

Silverton 

volcanl.c 

series 

San Juan tuff 

~uride congl. 

~--~~ ~----------~ Wasatch fm. 

Wasatch fm. 

Wasatch fm. Torre jon fm. 

Puerco fm. 

Poleo- Fort Union fm. 

~--~c~e~n~e~~~~--~~------~::::~::~;:~----1------------t-------------~Animas fm. 

Vermejo fm. Aropo_!loe fm ~ Me Dermott fm. 

(/) 

:::> 

0 

1.1.1 

0 

~ 

1-

UJ 

0:: 

0 

fl) 

:::J 

0 

CD 

u 

0 

~ 

0 

L. 

0 

Tri nldod 

Pierre 

ss. 

shale 

Loramie fm. Lance fm. Kirtland sh. 

Fox Hills s s. fruitland fm. 

Lewis shale 

CD CD j Twentymi I e ~ -o ss. mbr. ~ 1------------1 "-a. Williams Fork 

., ~::s fm. 

H . 0 0 1--r-------1 Mesavel"'de 

Pictured Cliff ss. 

Lewis shale 

·a. 

:J 

0 

Cliff House ss. L 1--------t 

0 

ygten e .,... jTrout Cr. 

CD ss. zone .;o ss. mbr. fm. • "- lies fm. ~ 

Menefee 

fm. ~ 1-----------11---I-.. - - - -4-----------t ~1--------t 

ll. 0 

., 

CD 

~ 

Point Lookout 

ss. 

~ Smoky Hill ~E Smoky Hill 

; ~.E marl. mbr. ;_.;;. marl. mbr. ~ ~.._ (Apishapa shale} ~ (Apishapa shale) 

:l z Ft=rfi:l~s ls.ls":'Jbr. z 

.C Cadell ss. mbr. 

., Carlile shale 

~ Greenhorn Is. ..... 

:; Graneros shale 

7 m !Thatcher Is. mbr. 

L-. Dakota s s. 

Ft. Hays Is. mbr. 

Codell ss. mbr. ~ 

Benton shale 

Mancos 

shale 

Frontier ss. mbr. 

Man cos 

shale 

Mancos 

shale 

0 Upper s s. Dakota ss. 0 U pp.er: ss. 0 Upper ss . 

-

fa. Kiowa shale ~- Middle sh. and ss. ~vi h Midddle -:; vii-:-.-M-i_d_d..,...le------lf--------------t .,~ ~_,..---------i 

~CD 

OL.. ..Jo ~., ~., s. an ss. ~., sfl. and ss. Burro Canyon ~::s ~ Lower 0 Low.sr 8 L ~ Chey.e_n_n_e __ ss_. _ _L _ _L_s~h~·~a~n~a~c~o~n~g~l~·~o-~~·s~-~a~n~a~c~o~n~g~I.L-__ L-_o_w_e_r ____ ss_.~----'-m_. _____ ~ ~--~--~~~ Adopted from a chart by the Research Committee 

of the Rocky Mountain Association of Geologists 

Figure 1.--Chart showing tentative correlations of Cretaceous and Tertiary rocks in Colorado. 

8 
Reserves for the field east of the 108th meridian 

were obtained from two reports by Hancock {1925 and 

1929), in which the reserves were estimated by the 

same method employed in the western part of the 

Yampa field. Reserves for the field west of the 108th 

meridian were calculated from acreages of coal land 

shown by Gale {1910) and the average total thickness 

of coal in several beds shown in his stratigraphic 

sections. 

Lower White River field. -The Lower White 

River field is in Rio Blanco and Garfield Counties. 

The coal is of bituminous rank and occurs in the 

Williams Fork formation of the Mesaverde group. 

Reserves in this field were calculated from average 

total thicknesses of coal in several beds as described 

by Gale (1910). The areal extent and thickness of 

overburden were estimated from his geologic maps and 

from recent field work by Geological Survey field 

parties. 

Book Cliffs field. -The Book Cliffs field includes 

parts of Garfield and Mesa Counties. In this field, 

2 to 5 workable bituminous coal beds are present in 

the Mesaverde formation. Each bed ranges from 3 to 

21 feet in thickness. 

The reserves for the field were taken from a 

report by Erdmann {1934, pp. 92-99), in which he drew 

thickness lines on each coal bed and calculated "immediate" reserves by coal beds within a strip of land extending 3, 000 feet back from the outcrop, and "future" 

reserves for an area extending a dis_tance back from 

the outcrop equal to one-half the length of the outcrop. 

Grand Mesa field. -The Grand Mesa field includes 

parts of Mesa and Delta Counties. The coal occurs in 

strata equivalent to the Paonia and Bowie members 

of the Mesaverde formation and is of bituminous rank. 

Reserves for the field were calculated from data 

contained in a report by Lee (1907, p. 332). The estimates were based on an average total thickness of 

several coal beds and an assumed limit of available 

coal 6 miles back from the outcrop. 

Somerset field. -The Somerset field includes 

parts of Delta and Gunnison Counties. Eight to 10 

workable beds of bituminous coal occurring in the 

Mesaverde formation a:re present in the field. Several 

of the coal beds each average from 6 to 7 feet in thickness; 

however, small areas of lenticular coal from 20 to 

42 feet in thickness are present. There is some coking 

coal in the field. 

Data used in calculating the reserves of the 

Somerset field were derived from reports by Lee (1907) 

and Johnson (1948). Johnson calculated reserves by 

estimating the thickness of individual beds and calculating the reserves under less than 3, 000 feet of 

overburden. His information included data derived 

from mines, core drilling, and field mapping. In 

the area adjacent to that mapped by Lee {1907) and 

Johnson {1948) reserves were computed by using average thicknesses of coal shown by Lee and Johnson and 

estimating the areal extent of the coal lying at a depth 

of less than 3, 000 feet. 

Crested Butte field. -The anthracite, semianthracite, and bituminous coal reserves of the Crested Butte 

9 

field in Gunnison County are in strata equivalent to the 

Bowie shale and overlying Paonia shale members of 

the Mesaverde. Several coal beds of minable thickness 

occur in each of the two members, and a total of eight 

beds have been observed in one locality. Accurate 

determinations of thickness are difficult because of the 

deformation in the area, but, in general, the thicker 

beds range between 4 to 22 feet in thickness. Comparatively large reserves of coking coal are present in the 

field. 

Reserves for a large part of the field were obtained 

from reserve figures in geologic reports by Emmons 

{1894), Lee {1912), and Johnson (1948). The reserves 

for most of the area, however, are taken from Lee's 

report. Lee obtained an average total thickness of coal 

in each district, estimated the areal extent of the beds, 

and computed the reserves from these data. In portions 

of the field not mapped by Lee, Johnson, or Emmons, 

reserves were calculated from data in the adjacent 

mapped areas. 

Carbondale field. -The Carbondale field includes 

parts of Pitkin, Gunnison, and Garfield Counties. The 

coal in this field occurs in the Mesaverde formation 

and is of bituminous rank. The coal present in Pitkin 

and Gunnison Counties will coke. The reserves were 

calculated by using the average total thickness in several 

beds shown in a report by Gale {1910), and by estimating 

the area under which the coal lies at depths of less than 

3, 000 feet. 

Grand Hogback field. -The Grand Hogback field, 

in Garfield and Rio Blanco Counties, contains coal of 

bituminous rank. The coal occurs in several zones in 

the Mesaverde formation. The reserves for the field 

were calculated by using Gale's estimated area of coal 

lands (1910, p. 112) and an average total thickness of 

the coal in several beds shown in his stratigraphic section. 

Tongue Mesa field 

The relatively small ·Tongue Mesa field, south of 

the Uinta region, includes parts of Montrose, Gunnison, 

and Ouray Counties. The field contains subbituminous 

coal in Mesaverde strata. The reserves were calculated 

from data on thickness of the coal and the measured areal 

extent of the coal-bearing rocks contained in a report 

by Storr {1901, p. 439). 

San Juan River region 

The San Juan River region is in southwestern 

Colorado and includes parts of Montezuma, La Plata, 

and Archuleta Counties. It occupies part of the SanJuan 

Basin, a broad structural depression approximately 

125 miles long, lying in southwestern Colorado and 

northwestern New Mexico. 

The coal is of bituminous rank. It occurs in the 

Dakota sandstone, the Menefee formation of the Mesaverde 

group, and in the Fruitland formation. The largest part 

of the reserves is contained in the Menefee and Fruitland 

formation. 

The Pagosa field in Archuleta County and the small 

coal-bearing areas in Montrose and Montezuma Counties 
northwest of the Durango field are not a part of the 

San Juan River region as shown on plate 1, but for 

convenience the reserves for these areas are included 

with the reserves of the region. 

Durango and adjacent fields. -The reserves for 

the Durango coal field were obtained from a report by 

Zapp (1949), which gives estimates for reserves in 

individual coal beds divided into thickness categories; 

overburden categories; and measured, indicated, and 

inferred categories. The coal occurs in the Menefee 

formation of the Mesaverde group and the Fruitland 

formation of Late Cretaceous age. The reserves for 

the large area southwest of the Durango field, chiefly 

in Montezuma County, were obtained from a report 

by Barnes (in preparation). Barnes calculated reserves partly by individual coal beds and partly by 

total thickness of the coal in zones containing several 

beds. He also calculated reserves for the western 

part of Archuleta County lying west of the Piedra River. 

The reserves for the area lying east of the 

Piedra River in Archuleta County were calculated 

from data on thicknesses of coal beds supplied·by 

Wood (1952). The coal in this area occurs in the 

Fruitland formation of Late Cretaceous age. 

Coal-bearing areas in Montrose and Montezuma 

Counties. -The coal reserves in Montrose and Montezuma 

Counties, located north of the Durango field, were 

calculated from data in unpublished geologic reports 

in the Geological Survey's files of field investigations 

of widely separated tracts of land. The coal found here 

is generally thin and very lenticular. It occurs in the 

Dakota sandstone. 

Pagosa field. -Reserves for the Pagosa field in 

Archuleta County were calculated from the information 

contained in a report by Cross (1935, p. 132). The 

coal is of subbituminous rank and occurs in the Animas 

formation of Late Cretaceous and Paleocene age. 

Raton Mesa region 

The Raton Mesa region is located in southern 

Colorado in Las Animas and Huerfano Counties. Structurally the area is a northward trending syncline with 

steep dips on the west side and gentle dips on the east 

side. 

In the northwestern part of the region, igneous 

intrusives have developed many local variations in 

the character of the coal and have aided in converting 

large quantities of lower rank coal into higher rank 

bituminous coal. The southern part of this region is 

the third largest producer of coking-coal in the West. 

The coal occurs in three zones, the lower in the 

Vermejo formation of Late Cretaceous age, and the 

middle and upper in the Raton formation of Paleocene 

and Eocene ages. The beds in the lower zone are most 

persistent and contain the highest rank bituminous coal 

in the field. 

As many as eight workable beds are present in 

parts of the field. They are generally discontinuous, 

however, and only a few are pe-rsistent over wide areas. 

The beds range from 2 to 14 feet in thickness. 

10 

The reserves for a part of the region were obtained from a report by Wood and others (1951) and 

in part from unpublished reports by Wood and others 

which include the results of recent field investigations. 

These calculations were made by the same methods 

as described for the eastern part of the Yampa coal 

field. 

Canon City field 

The Canon City field is in central Colorado in 

Fremont County. Structurally the field is a syncline 

with steep overturned dips on the west and gentle dips 

on the east. The coal is bituminous in rank and occurs 

in the Vermejo formation of Late Cretaceous age. The 

computations for the reserves in the field were made 

by individual beds, based on data in reports by Washburne 

(1908). 

South Park field 

South Park field in Park County occupies a faulted 

synclinal area about 20 miles long and 5 miles wide. 

The coal found in the field is bituminous in rank and 

occurs in three main beds separated by barren strata 

of considerable thickness. Although locally very thick, 

the beds are irregular in thickness and in many areas 

contain little workable coal. The age of the coal-bearing 

rocks in the field have not been determined precisely; 

however, they are believed to be correlative with the 

Laramie formation. 

An average total thickness of coal was used in 

calculating the reserves, based on data in reports by 

Washburne (1908). 

Denver region 

The Denver region is in northeastern Colorado 

and includes all of Denver County and parts of Adams, 

Arapahoe, Boulder, Douglas, Elbert, El Paso, Jefferson, 

Larimer, Morgan, and Weld Counties. Structurally 

the region is a broad basin extending southward from 

Wyoming past the middle of El Paso County in central 

Colorado. 

The coal in the Denver region is of subbituminous 

rank and occurs in the Laramie formation of Late 

Cretaceous age and in the Denver formation of Paleocene 

and Late Cretaceous age. 

Calculation of the reserves for the several small 

coal fields in the region were made from data obtained 

from several sources. The tonnages were estimated 

from the weighted average total thickness of coal in 

each coal-bearing zone and from the areal extent of 

the zones. The coal zones were assumed to extend 

4 miles basinward from outcrops and for a radius of 

2 miles from drill holes or small isolated mining areas. 

The data for the Northern coal field were derived from 

Eldridge (Emmons and others, 1896) and from a current investigation of the field by Spencer (in preparation). 

Data for the Scranton field and the fields west, southwest; and southeast of Denver were obtained from reports by Eldridge (Emmons and others, 1896), Dane 
qnd Pierce (1936), Brown (1943), and Allen (1951). 

Data for the field on the Larimer-Weld County boundary, 

just south of the Colorado-Wyoming line, were obtained 

from reports by Eldridge (Emmons and others, 1896), 

Allen (1939), and the Colorado State Planning Commission (1940); that on the Colorado Springs field from 

a report by Goldman (1908). 

North Park field 

The North Park field is in Jackson County in 

northwestern Colorado. The coal is of subbituminous 

rank and occurs in the Coalmont formation of Eocene 

age. Although the extent and thickness of the workable 

coal in many parts of the field have not been determined, 

it is not uncommon to find lenticular coal in beds 50 feet . 

or more in thickness. 

The reserve estimate for the field was obtained 

from a report by Beekly (1915, p. 115). His calculations were based entirely on one thick coal bed in 

one district and the area was limited to a tract where 

the coal lies at minable depth. The reserve figure, 

therefore, appears to be conservative. 

HISTORY OF COAL PRODUCTION 

The presence of coal in Colorado has been 

described by many early writers. In 1820, coal 

was noted in the Canon. City area by an exploration party headed by S. H. Long (James, 1823, 

p. 267). Later in 1848, General Emory found 

coal in the Raton Mesa region (Hayden, 1868, 

p. 199). Coal was mined commercially in the State 

in the Denver region as early as 1860 on Coal 

(Upper Sand) Creek, T. 4 S., R. 65 W. The earliest production records of the Colorado State Mine 

Inspector show that 43, 600 tons of coal was produced in Colorado during the years 1864-69, all 

of which was from the Denver region. (See table 5.) 

The highest annual production of coal was reached 

in 1917, when a total of 12~ million tons was 

mined. (See table 6. ) The record of past coal 

production in Colorado has been maintained largely 

through the office of the Colorado State Mine 

Inspector, and most of the figures presented in 

tables 5 and 6 were obtained originally from 

this source. 

The demand for coking-coal for use in the 

various industries of Colorado has increased considerably in the last few years. Approximately 

1 million tons of coking-coal is used annually in 

the State in the manufacture of coke. About 25 percent of this amount is imported from Arkansas, 

New Mexico, and Oklahoma to be used as a 

blend with the Colorado coals. Over a ten year 

period, 1939-49, the production of coke in the 

State increased markedly. The total production 

of coke in 1939 was approximately 398,000 tons, 

as compared to the total production in 1949 of 

739,000 tons. Although exact figures are not 

available, the reserves of coking-coal in the State 

are believed adequate to supply the 'demand for 

coke far into the future. 

Most coal in the State is mined by underground methods. Of the 4. 1 million tons of coal 

mined in 1951, more than 3. 7 million tons, 

or 91 percent, was produced from underground 

mines. Strip-mining has been carried on in the 

State since as early as 1931, although the 

amount of coal mined by this method did not 

exceed · 1 percent of the total State prodJ.lction 

until 1946. In 1951, however, 363, 000 tons, or 

9 percent of the total State production, was from 

strip mines. 

CONCLUSIONS 

With remaining reserves of 99, 450 million 

tons as currently estimated, Colorado contains 

larger reserves of coal than many coal-bearing 

states, particularly reserves of higher rank coal 

and coal suitable for making coke. Its present 

production of 4 to 5 million tons annually is 

exceeded in the West only by that of Utah and 

W~ming. With large reserves of high rank and 

high quality coal, and demonstrated productive 

capacity, Colorado stands as a storehouse of 

energy ready to be tapped as future needs dictate. 

Table 5.--Coal produced in Colorado from 1864-861 

(In short tons) 

Year Tons Year Tons Year Tons 

1864 500 1872 68,540 1880 437,005 

1865 1,200 1873 69,977 1881 706,744 1866 6,400 1874 77,372 1882 l,o61,479 

1867 17,000 1875 98,838 1883. 1,229,593 1868 10,500 1876 117,'666 1884 1,130,024 

1869 8,000 1877 160,000 1885 1,356,062 

1870 13,500 1878 200,630 1886 1,368,338 

1871 15,600 1879 322,732 Total 8,477,700 

1 U·. S. Geol. Survey Mineral Resources of the United States, 1886. 

11 
I-' 

M 

Year 

1887 

1888 

1889 

1890 

1891 

1892 

1893 

1894 

1895 

1896 

1897 

1898 

1899 

1900 

1901 

1902 

1903 

1904 

1905 

1906 

1907 

1908 

1909 

1910 

1911 

1912 

1913 

1914 

1915 

1916 

1917 

1918 

1919 

1920 35 1921 

1922 

1923 

1924 

1925 

1926 

1927 

1928 

1929 

1930 

1931 

1932 

Boulder 

288,218 

315,155 

323,096 

425,704 

498,494 

545,563 

663,220 

419,734 

377,395 

448,706 

477,790 

451,539 

540,475 

574,334 

482,975 

806,371 

803,924 

736,824 

839,804 

1,022,096 

1,296,729 

1,067,948 

1,332,322 

802,769 

954,752 

1,054,925 

902,918 

1,000,590 

946,888 

1,057,539 

1,277,663 

1,360,261 

1,122,485 

1,218,504 

851,686 

728,943 

628,002 

683,544 

619,985 

619,550 

441,991 

428,195 

480,126 

429,197 

498,o88 

578,921 

Table 6.--Coal produced in Colorado from 1887 to Jan. 1, 1952 by counties 1 

(In short tons) 

! 

Delta El Paso Fremont Garfield Gunnison Huerfano Jefferson 

--- 47,517 417,326 30,000 243,122 131,810 12,000 

--- 44,114 438,789 115,000P 258,374 159,610 9,000 

1,357 54,212 274,029 239,292 252,442 333,717 10,790 

775 25,617 397,418 183,884 229,212 427,832 10,984 

--- 34,364 545,789 191,994 261,350 494,466 17,910 

200 23,014 538,887 277,794 225,260 541,733 21,219 

2,580 19,415 536,787 212,918 258,539 521,205 1,895 

3,697 30,268 245,616 75,663 200,325 408,045 34,108 

4,514 51,840 315,344 274,271 239,182 386,696 --- 10 3,856 (11) 294,822 165,797 260,596 353,338 --- 5,765 8 12,849 304,589 182,884 297,417 367,894 13 15,445 

5,052 ( 11) 426,553 222,480 323,321 1,075,881 12,366 

6,100 27,668 620,609 134,354 319,434 632,577 9,900 

5,417 94,334 619,413 141,159 432,555 854,944 ( 11) 

5,844 175,979 536,313 173,707 397,043 918,609 ( 11) 

9,350 218,549 695,999 207,262 364,874 1,189,313 --- 13,029 207,797 633,858 176,354 436,604 1,319,666 --- 21,683 248,013 256,200 198,545 494,545 1,187,905 ( 11) 

9,497 188,775 512,002 172,~3 513,317 1,426,640 ( 11) 

6,812 210,793 666,034 193,063 583,175 1,803,791 ( 11) 

22,087 269,795 772,949 220,040 588,859 1,797,790 (11) 

37,689 317,763 669,274 220,099 503,140 1,644,068 (11) 

55,031 312,233 611,980 257,796 598,463 1,915,910 ( 11) 

63,590 336,780 722,142 189,755 640,982 2,387,090 (11) 

71,399 332,155 661,240 165,908 575,648 1,786,654 ( 11) 

75,043 334,904 738,833 185,452 557,685 1,899,538 ( 11) 

86,464 326,899 535,778 158,662 472,753 1,705,240 ( 11) 

86,861 280,577 169,271 112,842 402,045 1,724,265 (11) 

69,053 299,883 473,284 139,393 439,403 1,682,335 29 152,498 

70,696 312,670 605,108 133,771 512,265 1,884,943 29 185,704 

94,569 371,166 871,846 104,463 655,584 2,411,440 29 217,486 

89,476 301,647 871,326 92,655 652,770 2,586,911 126,330 

90,301 306,039 823,743 20,539 477,674 1,858,661 (11) . 

120,899 383,977 871,532 28,376 618,894 2,395,261 29 228,821 

89,935 288,531 590,821 16,795 479,007 1,755,750 36 181,027 

105,203 389,403 478,202 19,778 437,522 2,069,350 180,547 

107,600 355,583 613,463 22,340 542,992 1,965,417 36 214,047 

87,325 363,941 698,300 26,420 469,021 1,990,741 127,382 

70,120 296,640 634,788 30,263 513,880 2,102,470 41 104,087 

74,629 352,596 570,345 31,305 574,641 1,965,912 41 105,296 

91,793 356,510 447,485 30,279 559,116 1,815,930 60,332 

70,519 349,746 472,501 35,773 462,844 1,781,394 100,409 

74,360 359,146 531,670 44,906 518,786 1,772,558 98,826 

70,356 344,989 402,978 36,275 499,627 1,375,456 123,471 

60,529 345,761 345,882 31,585 402,117 978,268 140,314 

52,637 313,209 351,707 33,649 403,653 674,845 132,551 

La Plata Las Animas 

22,880 506,540 

33,625 706,455 

34,971 993,534 

43,193 1,154,668 

72,471 1,219,224 

81,500 1,171,069 

104,992 1,587,338 

53,571 1,153,863 

106,099 ·1,253,149 

104,661 1,261,555 

76,788 1,427,526 

100,650 1,211,340 

116,500 2,125,143 

123,524 2,123,411 

144,892 2,476,138 

155,029 3,245,271 

143,637 3,213,743 

146,080 2,808,953 

168,669 4,297,599 

173,720 4,768,882 

184,018 4,885,105 

166,090 4,190,801 

139,858 4,592,964 

147,755 5,548,085 

96,749 4,458,753 

132,487 4,708,698 

140,055 3,739,357 

132,317 2,693,288 

117,502 2,853,847 

108,603 4,042,937 

139,478 4,359,844 

138,963 4,250,291 

111,333 3,303,970 

127,732 4,219,086 

99,653 2,727,713 

79,086 3,370,064 

110,757 3,189,502 

92,136 3,118,572 

103,041 2,986,277 

106,004 3,299,599 

89,823 3,183,945 

86,568 2,910,631 

74,121 2,543,895 

56,876 1,945,290 

30,068 1,336,253 

22,541 859,107 
I-' 

w 

T 

1933 

1934 

1935 

1936 

1937 

1938 

1939 

1940 

1941 

1942 

1943 

1944 

1945 

1946 

1947 

1948 

1949 

1950 

1951 

otal 

production 

1889-1951 

Year 

1887 

1888 

1889 

1890 

1~91 1 92 

1893 

1894 

1895 

1896 

1897 

1898 

1899 

1900 

1901 

1902 

1903 

1904 

1905 

1906 

1907 

1908 

1909 

1910 

459,880 43,972 

461,796 36,609 

498,773 52,676 

503,274 69,049 

528,540 68,111 

590,351 54,984 

608,433 61,614 

622,556 65,707 

654,334 73,244 

711,320 94,662 

605,266 113,523 

604,039 120,216 

477,099 131,505 

377,639 98,899 

326,198 102,415 

235,074 97,554 

165,250 84,516 

109,565 71,560 

113,012 75,267 

42,078,337 3,609,775 

Mesa Moffat 

--- --- 300 --- 1,100 --- 1,000 --- 5,000 --- 5,050 --- 18,100 --- 31,750 --- 41,150 --- 28,979 --- 14 10,508 --- 14 10,690 --- 14 17,572 --- 14 8,990 --- 18 27,103 --- 19 432,464 --- 28,452 --- 26,450 --- 49,500 --- 37,696 --- 44,530 --- 59,250 --- 98,241 --- 129,530 ---

299,354 346,815 

299,293 352,736 

302,086 417,029 

291,802 492,542 

293,053 503,170 

264,308 471,012 53 428,380 510,007 

250,434 515,756 

237,552 516,161 

248,491 540,191 

249,436 567,648 

232,251 621,277 

215,206 552,199 

191,186 349,507 

214,494 429,600 

192,788 394,873 

126,992 339,651 

112,986 274,273 

89,622 281,937 

14,857,375 33,289,209 

Montezuma Pitkin 

--- --- --- 28,113 

816 --- 238 74,362 --- 91,642 

30 --- 90 99,211 

235 97,724 

190 --- 203 168,413 

(11) 171,111 

(,11) 195,496 

( 11) 15 174,172 

( 11) 175,942 

( 11) 325,872 

--- --- --- 20 346,774 --- 21 405,297 

--- 21 539,752 

(11) 22 542,519 

( 11) 22 564,380 

(11) 23 399,452 

( 11) 24 364,114 

--- 25 419,212 

28,162 404,573 572,833 141,592 21,918 855,569 

28,072 443,073 608,445 135,635 18,849 864,130 

40,315 491,254 668,748 137,533 28,660 953,791 

45,978 627,652 766,914 169,131 34,947 1,225,846 

52,394 659,163 787,683 179,096 40,180 1,425,197 

44,912 522,071 591,667 160,215 32,533 803,648 

37,978 530,425 615,167 (114 28,195 1,067,136 

34,925 619,249 753,133 1 7,501 29,146 1,252,332 

37,344 708,037 815,632 ( ) 1) 31,443 1,352,119 

53,768 774,358 982,815 147,057 43,534 1,457,318 

58,958 751,274 1,088,838 41 157,915 55,238 1,695,153. 

56,178 749,982 1,003,802 29 156,435 69,680 1,583,232 

58,037 775,803 882,897 29 150,662 68,342 1,432,208 

49,342 609,203 613,846 29 160,940 56,147 1,070,392 

51,956 623,110 585,181 29 164,097 48,977 1,289,582 

46,906 588,006 551,379 29 138,620 48,923 1,142,004 

49,667 491,485 439,130 29 97,096 45,091 889,306 

49,401 401,990 304,730 36 30,225 46,685 965,904 

39,649 338,071 311,812 36 10,315 41,936 998,445 

6,822,045 31,258,837 75,408,521 4,918,810 5,631,490 150,346,597 

Rio Blanco Routt Weld Other Small Total counti~s mines 

--- --- 48,401 2 43,921 1,791,735 --- --- 28,054 2 48,888 2,185,477 

2,900 1,491 28,628 3 '44,806 2,597,181 

200 705 46,417 4 54,794 3,077,003 --- --- 221554 5 57,374 3,512,632 

100 330 2,205 6 76,876 3,510,830 ... __ 816 35,355 7 39,928 4,102,389 

1,680 2,710 42,818 8 29,602 2,831,409 

1,761 2,767 27,934 9 690 3,082,982 

1,400 1,832 4,300 12 13,942 3,112,400 

1,882 945 8,310 --- 3,361,703 

1,341 1,339 24,085 12 14,214 4,076,347 

(11) 1,211 47,573 16 2,936 4,776,224 17 3,911 1,375 80,015 16 5,040 5,244,364 

(11) 1,558 33,374 16 608 5,700,015 

( 11) 3,180 73,681 --- 7,401,343 (11) 2,775 94,492 --- 2,497 7,423,602 

--- 5,568 118,862 --- 3,430 6,658,355 --- 3,643 101,812 --- 2,856 8,826,429 

( 11) 5,297 95,420 --- 1,920 10,111,218 

(11) 5,690 136,074 --- 2,190 10,790,236 (11) 13,005 343,414 --- 2,980 9,634,973 ( 11) 92,439 327,545 --- 18,040 10,716,936 

(11) 258,452 322,896 --- 4,698 11,973,736 
~ 

~ 

·year 

1911 

1912 

1913 

1914 

1915 

1916 

1917 

1918 

1919 

1920 35 1921 

1922 

1923 

1924 

1925 

1926 

1927 

1928 

1929 

1930 

1931 

1932 

1933 

1934 

1935 

1936 

1937 

1938 

1939 

1940 

1941 

1942 

1943 

1944 

1945 

1946 

1947 

1948 

1949 

1950 

1951 

Total 

production 

1887-1951 

Mesa 

92,881 

114,493 

134,438 

163,894 

101,327 

132,111 

179,222 

191,043 

116,321 

170,256 

113,761 

151,937 

180,574 

135,489 

126,011 

125,632 

113,823 

160,048 

113,151 

91,183 

90,398 

65,452 

68,919 

54,218 

65,755 

64,762 

78,268 

65,116 

77,464 

69,664 

106,254 

118,629 

100,188 

103,785 

106,732 

91,846 

103,790 

.. 97 ,651 

92,775 

88,437 

93,749 

5,624,85~ 

Table 6.--Coal ·produced in Colorado from 1887 to Jan. l, 1952 by counties 1 --Continued ---

Moffat Montezuma Pitkin Rio Blanco Routt Weld Other Small Total counties mines 

--- (11) 26 111,662 (11) 317,791 520,396 --- 11,395 10,157,383 --- (11) 27 222,286 --- 448,261 491,037 --- 14,182 10,977,824 --- --- 25 277,505 (11) 334,961 409,131 --- 8,349 9,232,510 --- e l) 28 256,959 (11) 666,384 475,734 --- 5,532 8,170,559 --- 30 2,375 15 52,143 (11) 852,315 432,501 --- 10,233 8,624,980 --- --- 15 42,861 (11) 915,028 464,959 --- 15,042 10,484,237 --- --- 15 26,693 (11) 1,074,103 654,977 --- 31 44,802 12,483,336 --- --- 3 2 98,078 (11) 941,355 637,609 --- 31 18,856 12,407,571 --- --- 33 225,136 ( 11) 1,181,332 659,660 --- 26,226 10,323,420 

(11) --- --- 34 6,472 964,342 920,073 --- 4,000 12,278,225 

(11) (11) 37 10,992 (11) 889,015 1,028,074 --- 14,869 9,137,629 

4,875 38 4,002 36 66,092 3,349 432,198 1,473,911 --- 25,135 10,019,597 

( 1 1) (11) 39 12,130 3,706 803,455 1,577,430 --- 19,220 10,346,218 

6,963 5,484 40 72,844 3,188 911,643 1,648,646 41 2,459 --- 10,444,098 

7,188 5,192 40 70,520 6,264 1,009,703 1,624,122 --- --- 10,310,551 

4,950 5,659 42 66,606 (11) 920,569 1,813,932 --- 10,637,225 

3,913 4,804 36 74,965 4,598 925,633 1,509,573 43 9,562 9,724,075 

4,896 6,086 44 83,~74 5,165 929,190 1,947,386 45 13,082 9,847,707 

5,853 5,163 29 75,025 5,977 1,006,157 2,196,258 45 14,763 9,920,741 

7,637 4,969 36 64,615 5,599 838,828 1,891,099 46 8,465 8,l96,9lb 

5,147 6,678 47 12,038 6,931 5'70,886 1,696,878 48 46,548 6,604,369 

3,798 3,677 49 49,247 5,323 572,458 1,472,519 13 3,427 5,598,721 

2,606 3,304 29 29,745 4,264 467,551 1,470,413 50 8,297 5,229,767 

2,945 5,056 29 25,672 3,937 485,311 1,375,783 50 9,373 5,210,933 

6,804 7,298 51 3,741 4,518 789,905 1,408,375 52 33,250 5,910,511 

6,871 4,510 51 3,601 5,206 987,338 1,480,260 52 32,119 6,811,802 

18,229 (11) 14 15,891 4,320 1,024,621 1,477,673 52 31,622 7,187,211 

35,205 ( 1 1 ) 14 30,159 4,254 741,431 1,231,371 52 19,907 5,663,144 

55,900 (11) 54 32,418 (11) 727,440 1,134,630 41 8,023 5,923,210 

48,162 10 43,218 55 7,694 ( 11) 909,942 1,197,585 52 21,738 6,588,742 

49,459 (11) 56 5,916 10 57,358 878,952 1,276,231 57 148,496 6,948,532 

65,817 --- (11} 56 15,064 10 1,231,608 1,585,159 36 15,889 8,085,680 29 100,689 --- --- 10 50,869 1,194,483 1,534,714 --- 8,324,192 

138,394 --- --- 10 54,497 1,187,237 1,484,263 41 2,445 8,167,713 

128,595 --- --- 10 40,796 1,093, 294 1,505,904 41 1,733 7,621,021 

142,923 1,251 --- 10 11,927 896,303 1,145,968 41 1,189 5,868,508 

146,494 --- --- 10 23,572 1,016,823 1,230,683 41 1,132 6,358,104 

144,288 --- --- 10 35,142 939,875 976,532 41 1,171 5,630,786 

130,404 1,295 4,327 10 48,050 807,289 823,013 41 1,095 4,636,432 

125,743 1,598 6,873 58 73,611 832,928 778,378 --- 4,274,887 

110,275 1,222 8,468 58 40,190 678,698 879,267 --- 4,111,945 

1~515,023 __ 1~4 ,6_431 7,329,734 549,322 L__34, 8o3 ,I64 51,686,326 869,404 256,452 470,980,516 -- --
~ 

01 

1 1864-92, 1900·32, U. S. Geol. Survey: Mineral Resources of the United States. 1893·99, U. S. Geol. 

Survey Annual Reports 16-2l .. 1932-49, U. S. .Bureau of Mines: Minerals Yearbook. 1950-51, Colorado State 

Mine Inspector Record. 2 Includes Arapahoe, Douglas, Dolores, and Park Counties •. 3 Includes Arapahoe, Douglas, Larimer, Park, and San Miguel Counties .. 4 Includes Arapahoe, Douglas, Dolores, Larime.·, Park, and San Miguel Counties. 6 Includes Arapahoe, Dolores, and Park Counties. 8 Includes Arapahoe, Douglas, and Park Counties .. 7 Includes Arapahoe, Douglas, Montrose, and Park Counties. 8 Includes Arapahoe County. 9 Includes Arapahoe and Montrose Counties. 10Includes Montrose County. 11 Production included elsewhere. 12 Includes Arapahoe, El Paso, and Larimer Counties. 13 Includes Larimer. 14 Includes Montrose. and Montezuma Counties. 16Includes Rio Blanco County. 18 Includes Arapahoe and Larimer Counties. 17 Includes Jefferson County .. 18Includes Jefferson, Rio Blanco, Montezuma, and Montrose Counties. 19Includes Arapahoe, Larimer, Montezuma, Ouray, Pitkin, and Rio Blanco Counties. 20Includes Arapahoe, Larimer, and Rio Blanco Counties. 21 Includes Adams, Jefferson, and Larimer Counties •. 22 Includes Adams, Archuleta, Jefferson, Larimer, Montezuma, and Rio Blanco Counties. 23 Includes Archuleta, Douglas, Jefferson, Larimer, Montezuma, and Rio Blanco Counties. 24 Includes Archuleta, Jefferson, Montezuma, and Rio Blanco Counties •. 215 Includes Archuleta, Jackson, Jefferson, and Rio Blanco Counties. 28 Includes Archuleta, Jefferson, Larimer, Montezuma, and Rio Blanco Counties. 27 Includes Archuleta, Jackson, Jefferson, and Montezuma Counties. 28 Includes Archuleta, Jackson, Jefferson, Montezuma, and Rio Blanco Counties 

29 Includes Jackson County •. 30Includes Archuleta County •. 31 Includes .Montrose and Ouray Counties. 32 Includes Jackson and Rio Blanco Counties •. 33 Includes Jackson, Jefferson, Moffat, and Rio Blanco Counties. 34 Includes Moffat County. 35Exclusive of Wagon Mines in 1921 and from 1924·52. 38 Includes Jackson and Elbert Counties. 37 Includes Moffat, Montezuma, Ouray, and Rio Blanco Counties. 38Includes Ouray County. 39Includes Archuleta, Moffat, Montezuma, and Montrose Counties. 40 Includes Archuleta, Jackson, and Montrose Counties. 41 fncludes Elbert County •. 42 Includes Archuleta, Jackson,Montrose, and Rio Blanco Counties. 43 Includes Dolores, Ouray, and San Miguel Counties. 44Includes Jackson and Montrose Counties. 46 Includes Dolores, Elbert, and San Miguel Counties. 48 Includes Dolores, Montrose, and Ouray Counties •. 47 Includes Montrose, Ouray, and Park Counties •. 48 Includes Archuleta, Elbert, Jackson, and Larimer Counties. 49 Includes Arapahoe, Elbert, Jackson, Montrose, and Ouray Counties. 60 Includes Elbert and Larimer Counties. 151 Includes Montrose and San Miguel Counties. 152 Includes Elbert, Jackson, and Larimer Counties. 63 Includes Jackson, Jefferson, and Larimer Counties •. 54 Includes Archuleta, Montezuma, Montrose, and Rio Blanco Counties. 515 Includes Archuleta and Rio Blanco Counties. 58 Includes Montezuma County. 57 Includes Elbert, Jackson, Jefferson, and Larimer Counties •. 158 Includes Archuleta, Montrose, and San Miguel Counties. 
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17 

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INT.-DUP. SEC., lASH.; D.C. ~032.5