DEPARTMENT OF THE INTERIOR

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, DIRECTOR

BULLETIN 499

COAL NEAR THE BLACK HILLS

WYOMING-SOUTH DAKOTA

BY

R. W. STONE

WASHINGTON

GOVERNMENT PRINTING OFFICE 

1912

CONTENTS.

Page.

Introduction.............................................................. 5

Geology.................................................................. 7

Structure............................................................ 7

Stratigraphy.......................................................... 8

Spearfish and Sundance formations................................ 9

Morrison shale..................................................... 9

Lakota sandstone.................................................. 9

Occurrence and character...................................... 9

Cambria..................................................... 10

Plum Creek................................................... 12

Oil Creek..................................................... 13

Aladdin....................................................... 15

Fusoii shale....................................................... 15

Dakota sandstone.................................................. 16

Graneros shale.................................................... 17

Coal..................................................................... 17

Introduction.........:................................................ 17

Occurrence'............................................................ 18

Aladdin.................................................:......... 18

Sundance......................................................... 21

Mason Creek..................................................... 24

Ridge west of Inyankara Mountain.............................. 24

Miller coal mine.............................................. 24

Philpott Canyon.............................................. 25

Dry Creekt ................................................... 27

Skull Creek...................................................... 27

Plum Creek....................................................... 31

Cambria......................................................... 32

History...................................................... 32

Mines and method of mining.................................. 33

Character of the bed........................................... 34

Village and mine equipment, by C. T. Lupton................... 38

Population and buildings.................................. 38

Railroad facilities.......................................... 39

Water supply.............................................. 39

Mechanical equipment..................................... 40

Workshops........................................... 40

Mining machinery..................................... 40

Ventilation............................................ 42

Tipple............................................... 42

Output.................................................. 42

Mount Zion................................................... 43

Little Oil Creek............................................... 43

3
4 CONTENTS.

Coal Continued.

Cambria Continued.

Robbersroost Canyon.......................................... 44

Salt Creek.................................................... 44

Edgemont..................................................... 45

East side of Black Hills........................................ 48

Character of the coal............................................... 48

Physical properties............................................ 48

Coking qualities............................................... 50

Chemical properties............................................ 51

Selection of samples...................................... 51

Composition.............................................. 52

Tests............................................................ 57

At the United States Geological Survey fuel-testing plant........ 57

Miscellaneous tests............................................. 60

Summary of tests............................................. 62

Gold in Cambria coal............................................. 63

Prospects for the future......................................:......... 64

ILLUSTRATIONS.

Page.

PLATE I. A, Lakota and Dakota sandstones on Little Oil Creek, near Cambria, 

Wyo.; B, Dakota sandstone dipping below surface 1 mile north of 

Newcastle, Wyo.............................................. 10

II. Typical cliffs and talus of massive Dakota sandstone.............. 16

III. A, StilwellCoalCo.'s mine and Lakota sandstone at Aladdin, Wyo.;

B, Lakota sandstone in Camp Canyon, near Cambria, Wyo ...... 18

IV. Sections of coal beds near Black Hills............................ 34

V. A, Cambria Fuel Co.'s tipple at Cambria, Wyo.; B, View of Cambria, Wyo.................................................... 38

VI. Opening on coal at Mount Zion ranch, near Cambria, Wyo......... 42

VII. Photographs showing physical characters of different coals.......... 48

FIGURE 1. General map of Black Hills region, showing areas covered by largescale maps ................................................... 6

2. Sketch map of mines and prospects near Aladdin, Wyo............ 19

3. Coal area in sees. 13 and 24, T. 51 N., R. 64 W.................... 22

4. Map showing location of Sundance and Mason Creek prospects..... 23

5. Sketch map showing location of prospects at Holwell ranch, 'northwest of Newcastle, Wyo ....................................... 28

6. Extent of mine workings at Cambria, Wyo......................... 33

7. Map showing location of coal near Edgemont, S. Dak.............. '46

8. Diagrammatic section of coal bed exposed in bank of Cheyenne River,

east of Edgemont, S. Dak...................................... 47
COAL NEAR THE BLACK HILLS, WYOMING-SOUTH

DAKOTA.

By R. W. STONE.

INTRODUCTION.

Nine townships on the west side of the Black Hills were examined 

by the writer in the fall of 1908 for the purpose of making a classification of the public lands with respect to coal. (See fig. 1.) The 

townships examined were T. 45 N., Rs. 61-62 W.; T. 46 N., Rs. 61-62 

W.; T. 47 N., Rs. 62-63 W.; T. 48 N., Rs. 62-63 W.; and T. 49 N., 

R. 63 W. This area is in the Sundance and Newcastle quadrangles, 

and its geology is mapped and described in folios Nos. 107 and 127 of 

the Geologic Atlas of the United States. The field examination was 

therefore confined to the outcrop of the coal horizon and the areas 

underlain by coal as shown in the folios. All known coal exposures 

and prospects along the coal horizon were examined and a small 

amount of excavating was done. C. T. Lupton, M. I. Goldman, and 

F. D. Morrison assisted in the field work, which occupied about 

three weeks. In June and July, 1909, the writer spent a week 

studying the coal near Aladdin and Sundance, Wyo., and Edgemont, 

S. Dak., for land classification purposes.

When the field examinations were made publication of their results 

was not contemplated, but after the data had been used for land 

classification the writer found time in 1911 to arrange them in a 

form suitable for publication, which seemed desirable because the 

two field examinations included all known important coal exposures 

near the Black Hills. This report is made for the purpose of assembling the information concerning coal in the reports cited below, 

together with the considerable amount of new data obtained by the 

writer.

The following list includes papers which deal with the coal resources 

of the Black Hills. All of them, except the four last cited, are 

publications of the United States Geological Survey.

BARTON, N. H., Newcastle folio (No. 107), Geol. Atlas U. S., 1904. 

DARTON, N. H., and SMITH, W. S. T., Edgemont folio (No. 108), Geol. Atlas U. S., 

1904.

5
6 COAL, NEAR BLACK HILLS, WYO.-S. DAK.

BARTON, N. H., Sundance folio (No. 127), Geol. Atlas U. S., 1905. 

DARTON, N. H., and O'HARRA, C. C., Aladdin folio (No. 128), Geol. Atlas U. S., 1905. 

BARTON, N. H., The coal of the Black Hills, Wyoming: Bull. No. 260, 1905, pp. 

429-433.

BARTON, N. H., Geology and underground-water resources of the central Great 

Plains: Prof. Paper No. 32, 1905, pp. 374-379.

BARTON, N. H., Geology and water resources of the northern Black Hills and

adjoining regions in South Bakota and Wyoming: Prof. Paper No. 65, 1909, pp. 93-94.

BARTON, N. H., Geology and water resources of the southern half of the Black

Hills and adjoining regions in South Bakota and Wyoming: Twenty-first Ann. Kept.,

pt. 4, 1901, pp. 582-584.

JENNEY, W. P., Field observations in the Hay Creek coal field: 

Nineteenth Ann Kept., pt. 2,1899, 

pp. 568-593.

PARKER, E. W., HOLMES, J. A., 

CAMPBELL, M. R., committee in 

charge, Preliminary report on the 

operations of the coal-testing plant 

of the United States Geological 

Survey at the Louisiana Purchase 

Exposition, St. Louis, Mo., 1904: 

Bull. No. 261, 1905, pp. 28-29, 59, 

83, 115-117, 119.

PARKER, E. W., HOLMES, J. A., 

and CAMPBELL, M. R., committee 

in charge, Report on the operations of the coal-testing plant of 

the United States Geological Survey at the Louisiana Purchase Exposition, St. Louis, Mo., 1904: Prof. 

Paper No. 48, 1906.

HOLMES, J. A., in charge, Preliminary report on the operations 

of the fuel-testing plant of the 

United States Geological Survey 

at St. Louis, Mo., 1905: Bull. No. 

'290, 1906, pp. 224-229.

Mineral Resources of the United 

States for 1900, 1901, p. 535.

Mineral Resources of the United 

States for 1908, 1909, p. 196, and 

for previous years.

STORRS, L. S., The Rocky Mountain coal fields: Twenty-second Ann. Rept., pt. 

3, 1902, p. 440.

CHANCE, H. M., The resources of the Black Hills and Bighorn country, Wyoming: 

Trans. Am. Inst. Min. Eng., vol. 19, 1890-91, 1891, pp. 49-58.

CHANCE, H. M., The Biscovery of New Gold Bistricts: Trans. Am. Inst. Min. 

Eng., vol. 29, 1899-1900, 1900, pp. 227-228.

CHENHALL, J. W., Coal mining by mechanical appliances: Min. Proc. Inst. Civil 

Eng., London, vol. 139, 1900, pp. 323-333.

TODD, J. E., Mineral building materials, fuels, and waters of South Bakota: Bull. 

S. Bak. Geol. Survey No. 3, 1902, p. 110-111.

Several lengthy excerpts, mostly geologic sections, have been taken 

from N. H. Barton's reports for the chapter on stratigraphy. The

FIGURE 1. General map of Black Hills, showing areas 

covered by large-scale maps.
GEOLOGY. 7

writer desires to acknowledge indebtedness to him also for many helpful suggestions and cordial interest in this paper. The notes for the 

chapter on the civic and mechanical equipment at Cambria were 

collected by C. T. Lupton, and those pages were written by him. 

The writer wishes to thank L. T. Wolle, secretary and treasurer, and 

W. E. Mouck, superintendent, of the Cambria Fuel Co. for much 

valuable information and kindly assistance. He is indebted to 

C. T. Lupton, M. I. Goldman, and F. D. Morrison, who assisted him 

in the field, for their efficient work in searching for and examining 

coal prospects under weather conditions at times most disagreeable. 

The work was done under the supervision of M. R. Campbell, geologist 

in charge of the economic geology of fuels, to whom the writer is 

indebted for helpful suggestions and criticisms.

GEOLOGY.

STRUCTURE.

The Black Hills, located on the boundary between South Dakota 

and Wyoming, form an important geologic and physiographic interruption in the Great Plains, which extend from the foot of the Rocky 

Mountains eastward to the Valley of the Mississippi. Rising several 

thousand feet above the plains, and well covered with timber and 

other vegetation because of the abundant rainfall, they contrast 

strongly with the surrounding treeless plains. Structurally, they 

constitute a dome-shaped uplift, in which sedimentary rocks much 

older than those forming the surface of the Great Plains were lifted 

high above their general level. Erosion has unroofed this dome, 

exposing successive formations in concentric rings around the central hills.

The salient features of the uplift are (1) a central area of crystalline rocks forming high ridges which culminate in Harney Peak; (2) 

a limestone plateau with mfacing escarpment; (3) a continuous 

trough, the Red Valley, completely encircling the plateau; and (4) 

an outer rim of flat-topped ridges which in most parts presents a 

steep face toward the Red Valley and a fairly flat surface sloping 

gradually away from the central area.

In early Tertiary time, probably during the period of uplift in 

which the doming occurred, there was more or less igneous activity, 

which resulted in the development of laccoliths, largely composed of 

monzonite and syenite porphyry.

The central area is eroded in Archean and Algonkian granite, 

schist, and quartzite, which contain valuable minerals in many places. 

High mountains in this area are separated by parklike valleys which 

narrow to canyons where the streams pass through the surrounding 

limestone plateau.
8 COAL NEAR BLACK HILLS, WYO.-S. DAK.

The general level of the limestone plateau is higher than that of 

the igneous area, so that the central hilly group forms a basin. For 

many miles the limestone presents a line of cliffs rising several hundred feet above the valleys of the central area and locally it attains 

altitudes almost equaling Harney Peak. All around the Black 

Hills the limestone plateau slopes outward and is notched by deep 

canyons of the streams escaping from the open valleys of the inner 

basin.

The encircling Red Valley is bordered on the inside by the long 

slopes of the limestone plateau and on the outside by the escarpment 

of the outer rim. Although the valley appears to be continuous the 

main streams from the center of the hills cross it without much 

digression, but the divides between them are so low that the valley 

character of the encircling depression is conspicuous. The red color 

of the rocks and soil and the lack of trees are distinctive. The Red 

Valley commonly is 2 to 3 miles wide, but becomes narrower where the 

rocks dip at a greater angle or where interrupted by minor doming, 

as at Inyankara and Strawberry mountains, on the west side of the 

Black Hills.

The outer rim of the hills at the north and south, and locally along 

the middle western section, spreads out in a long, gentle apron, sloping away from the uplift. A fine example of the smooth plateau surface sloping away from the dome and presenting an infacing escarpment is seen north of Edgemont, S. Dak., and also southwest of 

Sundance, Wyo. This ridge, or slightly tilted plateau, is made by 

the massive Dakota and Lakota sandstones, and, since coal is found 

only in these formations, is the only part of- the Black Hills uplift 

with which this report is concerned. All the coal known in the Black 

Hills is in the outer rim, and with the exception of some minor localities near Edgemont, S. Dak., is in Wyoming.

Knowledge of only a portion of the geologic column is essential to 

an understanding of the relations of the coal, and therefore only the 

stratigraphy from the top of the Sundance to the Graneros shale is 

described in detail.

The following description of the geologic formations is adapted 

from that by N. H. Darton in the Newcastle, Edgemont, Sundance, 

and Aladdin folios. 1

STRATIGRAPHY.

The formations mentioned in the following pages, named from 

youngest to oldest, are Cretaceous: Graneros shale, Dakota sandstone, Fuson shale, Lakota sandstone; Jurassic (?): Morrison shale; 

Jurassic: Sundance formation; Triassic (?): Spearfish formation.

Newcastle folio (No. 107), Edgemont folio (No. 108), Sundance folio (No. 127), Aladdin folio (No. 128); 

Geol. Atlas U. S., U. S. Geol. Survey, 1904,1905.
GEOLOGY. 9 

SPEARFISH AND SUNDANCE FORMATIONS.

The Spearfish formation, commonly known as the "Red Beds" by 

reason of its color, is the most easily recognized stratigraphic unit in 

the area. Its material is red sandy shale with intercalated beds of 

gypsum, and it varies in thickness from 450 to nearly 700 feet.

Lying upon the Spearfish formation is the Sundance formation, of 

Jurassic age, composed of sandstone and shale so different lithologically from the red beds below and the Morrison shale above as to be 

readily recognized. Buff sandstone and greenish gray shale with 

fossiliferous limestone are characteristic. The thickness is from 200 

to 350 feet.

MORRISON SHALE.

Unconformably upon the Sundance formation lies a shale formation known as the Morrison, which is of Jurassic or Lower Cretaceous

age. It averages about 150 feet in thickness and consists of massive 

shale with thin layers of fine green sandstone. Buff, pale-green, and 

maroon colors give character to the general drab color of this shale 

and make the formation readily recognizable. The soft color of the 

weathered outcrop can not easily be mistaken for the buff of the 

Sundance or the bright red of the Spearfish formation.

The Morrison shale outcrops in a narrow belt under the cliffs of 

Lakota sandstone along the east face of the so-called Hogback Ridge 

in Wyoming. The outcrop is often obscured by talus from the sandstone cliffs above and by soil derived from its own disintegration. 

Good exposures are to be seen along Mason Creek near the county 

line, on Skull Creek near the Holwell ranch, in Black Canyon and 

along Oil Creek, and in the long straight bluff of the table on the west 

side of Salt Creek. East of Salt Creek it is extensively exposed by 

the removal of the Lakota sandstone. The formation is poorly 

exposed near Aladdin but appears to be about 60 feet thick.

Its relations and fauna in other regions suggest that the Morrison 

is of fresh-water origin. It contains fossil bones of saurians which 

some paleontologists deem to be of late Jurassic age; others class them 

as early Cretaceous.

LAKOTA SANDSTONE.

Occurrence and character. The prominent escarpment which flanks 

the encircling outer rim of the Black Hills is produced by the massive 

hard sandstones of the Lakota and Dakota formations. The ready 

weathering of the soft shale beneath enhances the relief and the 

sandstones outcrop in high cliffs. Owing to low dip and deep canyons, 

the outcrop of the main body of sandstone is very long and is flanked 

by numerous outlying buttes.
10 COAL NEAR BLACK HILLS, WYO.-S. DAK.

The Lakota sandstone is usually from 150 to 300 .feet thick, and is 

composed of coarse-grained, massive, and cross-bedded sandstone 

with thin partings of shale. The color is commonly buff but may be 

light gray or even white. Some of the basal sandstone is markedly 

white and of sugary texture; much white sandstone is found in Oil 

Creek valley, especially west of the T E ranch.

At or near the base there is a coal horizon in which occurs an erratic 

bed of bituminous coal. In a small area about Cambria the coal is 

from 4 to 10 feet thick, and at the Hoi well ranch on Skull Creek it is 

known to be from 6 to 9 feet thick. Elsewhere, however, the bed is 

either badly broken by partings, is very thin, or is represented by 

carbonaceous shale.

Cambria. Typical sections of the Lakota and closely associated 

formations in the vicinity of Cambria, measured by Darton and published in the Newcastle folio, are here given, the first being compiled 

from surface exposures near Cambria and from the record of a bore 

hole sunk on the plateau and passing down through the Antelope mine.

Section of Lakota and associated formations at Cambria, Wyo.

Dakota: Feet. 

Sandstone, thin bedded, at top of table...................... 20

Sandstone, hard, massive, buff colored..................... 40

Fuson:

Shale and talus [concealed beds]............................ 20

Lakota:

Sandstone, light colored, conglomeratic in part............. 60

Talus [concealed beds] and sandstone ledges ................ 70

Sandstone, light-gray, soft, fine-grained..................... 50

Coal.................:................................... 7

Sandstone, hard, light brown............................... 5

Sandstone, soft, dark brown............................... 2

Sandstone, light-gray, moderately hard..................... 1£

Coal with sandstone, shale, and pebbly layers............... £

Sandstone, dark-gray, soft................................. 1

Coal, shales, and sandstone ................................ 2

Morrison:

Clay, gray................................................. 3

Sandstone, light-gray, moderately hard..................... 1£

Clay..................................................... 7i

Sandstone, gray, upper half very hard....................... 4

Shale with some thin sandstones........................... 54+

In the canyon of Little Oil Creek below Cambria high walls of 

Lakota sandstone surmounting a slope of Morrison shale, from 40 to 

90 feet high, are capped by Dakota sandstone with underlying Fuson 

shale (PL I, A). A section 2 miles above Newcastle is as follows:
U. S. GEOLOGICAL SURVEY IULLETIN 499 PLATE I

[.Dakota 

' sandstone

takot a

sandstone

A. LAKOTA AND DAKOTA SANDSTONES ON LITTLE OIL 

CREEK NEAR CAMBRIA, WYO.

B. DAKOTA SANDSTONE DIPPING BELOW SURFACE, 1 MILE NORTH OF NEWCASTLE, WYO.
GEOLOGY. 11

Section of canyon of Little Oil Creek above Newcastle, Wyo.

Dakota: Feet. 

Sandstone, thin bedded................................... 20

Sandstone, massive, reddish............................... "30

Fuson:

Shales and thin sandstones.................................. 15 ±

Lakota:

Sandstone, buff, partly concealed........................... 40±

Sandstone, massive, nearly white. ........................... 45

Shale with coaly layers...................................... 6

Sandstone, gray to brown.................................. 20±

Morrison:

Shale to bottom .......................................\ ... 90

These formations pass beneath the surface north of Newcastle, 

where the dip within a short distance changes from 3° to 22°. Plate 

I, B, shows the Dakota sandstone as exposed in a railroad cut north 

of Newcastle.

On the east side of the ridge, 2 miles south of Cambria, the bluff 

exposes the following section of the Lakota and associated formations:

Section on east side of ridge 2 miles south of Cambria, Wyo.

Dakota: Feet. 

Sandstone, rust colored, thin bedded at top and bottom........ 33

Fuson:

Clay, massive, purple to maroon.............................. 17

Lakota:

Sandstone, massive, dull gray above, yellowish tan color below. 40 

Shale, purplish, partly covered by talus....................... 12

Sandstone, massive, salmon to brick red...................... 60

Sandstone, massive, white.................................... 8

Bottom concealed by talus.

On the west side of the ridge, opposite, many scattered outcrops of 

sandstones show considerable local variations in color. At one point 

a 5-foot coal bed is exposed. The following section sets forth the 

principal features:

Section on west side of ridge 2 miles south of Cambria, Wyo.

Dakota: Feet. 

Sandstone, light brown, mostly thin bedded.................. 30

Fuson:

Talus...................................................... 35

Lakota:

Sandstone, massive, salmon colored, conglomeratic at base.... 60

Talus, on sandstone in part.................................. 35

Sandstone, light gray to buff................................ 35

Shale, gray................................................ 4

Sandstone, massive, brown................................... 12

Coal and bone............................................. 1£

Sandstone, massive, brown................................... 2

Coal, underlain by some sandstone........................... 5

Morrison: 

Shales.
12 COAL NEAR BLACK HILLS, WYO.-S. DAK.

Plum Greek. On the west side of East Plum Creek a thickness of 

about 160 feet of massive light-colored sandstones shows local conglomeratic streaks and some intercalations of thinner-bedded members about 70 feet above the base. The details of a partly wellexposed section just north of Deford's ranch, 2 miles northwest of 

Cambria, are as follows:

Section on west side of East Plum Creek 2 miles northwest of Cambria, Wyo.

Dakota: Feet. 

Sandstone, massive, tan colored.............................. 20

Dakota(?) and Fuson:

Sandstones, thin bedded, and shales of various colors.......... 53

Lakota:

Concealed.................................................. 40

Sandstone, massive, pale pink to buff, conglomeratic at base... 15 

Sandstone, light buff, cross-bedded, conglomeratic at base..... 22

Unconformity (?). 

Sandstone, compact, pale pink to light gray. ................. 12

Sandstone, coarse, conglomeratic, brown........................ 18

Sandstone, dark buff........................................ 24

Impure coal and coaly shale.................................. 6

Sandstone and ehale......................................... 3

Coaly shale and thin coal beds............................... 7

Sandstone, massive, tan colored.............................. 6

Shale, sandy, light gray..................................... 2

Sandstone, massive, buff..................................... 30

Concealed.................................................. 15

Morrison:

Shale....................................................... 90+

In the canyon just southwest of Mount Zion ranch the Lakota and 

associated formations are as follows:

Section in canyon southwest of Mount Zion ranch, Wyoming.

Dakota: Feet. 

Sandstone, massive, light colored........................... 30

Fuson:

Sandstone and dark shales................................. 20-30

Lakota:

Sandstone, buff and tan colored, conglomeratic streaks...... 115

Coal, bony................................................ J

Sandstone, hard........................................... 3

Coal...................................................... 4

Sandstone with carbonaceous streaks...................... 1

Coal...................................................... 2

Sandstone, massive, partly cross-bedded, nearly white...... 40

Morrison:

Shale, greenish.
GEOLOGY. 13

Oil Greek. In Oil Creek and Blacktail canyons the Lakota varies 

in thickness from 125 to 160 feet. A typical section, including the 

Fuson and Dakota formations, on the west side of Oil Creek canyon 

1$ miles below the mouth of Plum Creek has the folio whig components :

Section on west side of Oil Creek canyon 1\ miles below mouth of Plum Creek, Wyo.

Dakota: Feet. 

Sandstone, massive, rust colored............................. 40

Dakota?:

Shale, sandy, gray........................................... 9

Sandstone, reddish.......................................... 2

Fuson (in greater part):

Sandstone, thin bedded, gray................................. 1

Sandstone, dark pinkish..................................... 5

Sandstone, thin bedded, rust colored, with dark shale layers.... 25

Shale, gray.................................................. 10

Sandstone, reddish.......................................... 2

Shale, carbonaceous......................................... 1

Concealed.................................................. 3

Sandstone, cross-bedded, gray................................. 12

Concealed.................................................. 15

Lakota:

Sandstone, cross-bedded, massive, light colored (in part Fuson). 30 

Sandstone, conglomeratic, light gray........................... 25

Sandstone and coaly shale................................... 2

Unconformity (?). 

Sandstone, massive, rust colored above, lighter below.......... 19

Shale and sandstone, gray................................... 20

Sandstone, massive, reddish tan to salmon colored.............. 30

Morrison:

Talus and shale.............................................. 80

The cliffs on the west side of Oil Creek canyon above the mouth 

of Plum Creek exhibit the following section:

Section on west side of Oil Creek.canyon 2 miles above mouth of Plum Creek, Wyo.

Dakota: Feet. 

Sandstone, massive, tan colored.............................. 55

Shale, sandy, gray............................................ 3

Sandstone, thin bedded, rust colored......................... 24

Fuson and Lakota:

Concealed.................................................. 50

Lakota:

Sandstone, massive, cross-bedded, gray........................ 15

.Sandstone, massive, cross-bedded, conglomeratic, tan to salmon 

colored................................................... 36

Sandstone, thin bedded, rust colored, with some shale........ 8

Shale, gray................................................; 1

Sandstone, massive, cross-bedded, tan colored................. 25

Shale, carbonaceous......................................... $
14 COAL NEAR BLACK HILLS, WYO.-S. DAK.

Unconformity.

Feet.

Sandstone, thin bedded, gray................................. 6

Shale, purple................................................ 1$

Sandstone, massive, cross-bedded, light gray................... 24

Sandstone, massive, cross-bedded, rust-red colored............. 30

Morrison:

Shale to Oil Creek........................................... 6

Owing to a local flattening of dips a short distance north, the lower 

sandstone descends to the water level and crosses the valley, but it 

rises again within a short distance, and 3 miles farther north it is 

more than 150 feet above the creek; however, its thickness is greatly 

diminished.

Although the above sections do not show the feature, the lowermost beds of the Lakota in some places are fine conglomerate or grit. 

This grib consists of closely compacted and well-rounded white, gray, 

black, pink, and red quartz, quartzite, and chert pebbles one-eighth 

inch in diameter in a matrix of white clay. It is well exposed at the 

coal openings in sec. 31, T. 48 N., R. 62 W., near the Holwell ranch, 

where the coal is underlain by a hard iron-bearing sandstone. j

The variations in stratigraphy shown in the sections given above, 

and the presence of a coal bed give the formation special interest. 

In the plateaus north of Newcastle the upper member of the Lakota 

is a massive sandstone of gray color usually about 90 feet thick and 

in places having conglomeratic streaks. The base of this member 

shows considerable evidence of local unconformity and in places 

contains a thin band of coaly shale. Next below is a massive, finegrained, even-textured sandstone, commonly light ash-gray near the; 

top but much darker below and locally rusty or tan colored throughout; it averages about 50 feet thick.

Under it is found the main coal horizon, which, with the thinnerbedded sandstones and shales underlying the coal, in some places 

attains a thickness of 25 feet. Where the coal is thin or absent its 

horizon is either immediately above the Morrison shale or an inter-, 

vening thin layer of sandstone. Outside the Cambria basin the coal 

thins rapidly and merges into a carbonaceous shale thab contains 

thin seams of coal. Along the west side of East Plum Creek the main 

coal horizon is represented by 12 or 14 feet of coaly shale containing 

scarcely any usable coal.

In the upper sandstone of the Lakota in the region west of Newcastle two pebble bands appear in most of the exposures. The upper 

is a small gray conglomerate layer in a massive tan-colored sandstone. The lower contains coarse rust-red pebbles scattered more 

or less thickly through a 10 to 12 foot bed lying about 30 feet above 

the coal horizon. Light tan-colored massive sandstone, varying in 

thickness but averaging about 20 feet, separates the two conglomer-
GEOLOGY. 15

atic layers. The carbonaceous shale in the middle of the Lakota 

sandstone is well developed on Oil Creek and its branches, but it is 

of variable thickness and composition. It contains some thin coaly 

layers and has been prospected in places with the hope thatj.t would 

prove to be an upper coal horizon.

Aladdin. The Lakota sandstone is conspicuous on Hay Creek in 

the vicinity of Aladdin, where with the Dakota sandstone it makes 

prominent cliffs. It is somewhat thinner than at Cambria, averaging 

rather less than 150 feet. A section measured by Prof. Jenney is as 

follows:

Section of Lakota sandstone at Aladdin, Wyo.

Fuson shale. Feet.

Sandstone, massive, yellow, cross-bedded; forming cliffs........... 35

Conglomerate; small pebbles of flint and quartz.................... 3

Breccia; angular fragments of sandstone and shale in white clay... 3-10

Sandstone, yellow.............................................. 10

Sandstone, massive, gray, thin layers; forming cliffs.............. 30

Shale, drab, clay, with plant remains............................ 2-5

Shale, soft, sandy, with carbonized plants........................ 2

. Coal........................................................ 1

Sandstone, soft yellow........................................... 4

Shale, drab, clay................................................ 12

Coal........................................................ 3

Shale, drab, clay (Morrison?). 

115

Sections measured at two or three places west and south of Aladdin 

show the Lakota somewhat thicker.

The Lakota sandstone is well exposed in all the canyons north of 

Edgemont, S. Dak. . Cheyenne River cuts a canyon through it at 

the anticline about 4 miles east of the town, revealing this section:

Section of Lakota sandstone 4 miles east of Edgemont, S. Dak.

Feet. 

Sandstone, massive, fine-grained, white........................... 100

Sandstone, slabby, and shale...................................... 40

Sandstone, massive, fine grained, light gray....................... 40

Sandstone, shaly and thin bedded................................ 10

Sandstone, massive, white to dirty gray............................ 230

420

In deep well borings at Edgomont this sandstone was recorded as 

222 feet thick.

FUSON SHALE.

A band of shale and thin-bedded sandstones lying between the 

massive Lakota and Dakota sandstones is known as the Fuson shale. 

Its thickness ranges from 10 to 100 feet. Because of its position
16 COAL NEAR BLACK HILLS, WYO.-S. DAK.

between massive sandstones, it is commonly obscured by talus. The 

pink, red, maroon, gray, and buff shales give the formation a readily 

distinguishable character. On the west side of Oil Creek, near the 

T E ranch, the formation consists of 20 feet .of dark-gray shale and 

sandy shale overlain by 6 feet of thin-bedded buff sandstone. On 

Mason Creek, in sees. 5 and 6, T. 48 N., R. 62 W., bands of carbonaceous shale a few inches thick, have been found in the formation. 

Although the outcrop is commonly hidden, some good exposures can 

be found in the steep cliffs.

At the north end of the Black Hills the Fuson is reported to be a 

little thicker than on Mason Creek. On the south fork of Hay Creek 

at Aladdin the following section was measured by Prof. Jenney:

Section of Fuson shale at Aladdin, Wyo.

Dakota sandstone. Feet. 

Talus........................................................... 15

Sandstone, yellow-brown......................................... 5

Talus........................................................... 12

Sandstone, yellow-brown........ '................................. 6

Clay, purple, partly exposed...................................... 20

Sandstone, yellow, thin bedded.................................. 15

Lakota sandstone, massive. ' 

73

Half a mile west the formation appears to be 102 feet thick, whereas 

a mile south of the south side of the ridge it is 70 feet.

Well-preserved fossil leaves found in the base of the shale in the 

vicinity of Aladdin place these beds in the Lower Cretaceous.

DAKOTA SANDSTONE.

The Dakota is a coarse-grained buff-colored sandstone ordinarily 

from 140 to 150 feet thick, which forms the upper and outer surface 

of much of the outer rim of the Black Hills. It is described above 

(pp. 9-13) in connection with the Lakota sandstone. The Dakota 

sandstone is often massively bedded and cross-bedded, merging into a 

thin-bedded variety in the upper portion. Reddish color is characteristic of the massive lower, cliff-forming member, from which the rock 

breaks off in great vertical slabs or rude columns. (See PI. II.) 

This massive character is lacking in some localities, especially north 

of Newcastle, where the formation is softer or thinner bedded.

An exceptional phase of the formation is exposed in the canyon of 

Little Oil Creek just above Newcastle, where it is represented by a 

series of alternating, mostly thin-bedded sandstones and shales of 

dark color. As the Fuson shale is less distinctive here than usual 

it is difficult to recognize the precise dividing line between the two 

formations. On the branches of Plum Creek the Dakota has been 

extensively eroded, but small outliers remain on the summits of some
U. S. GEOLOGICAL SURVEY 

TYPICAL CLIFFS AND TALUS OF MASSIVE DAKOTA 
GEOLOGY. 17

of the adjoining ridges. Its identity is in some places doubtful. In 

the region north of Newcastle there is a general thinning of the 

'formations to the north and northeast. On the high tables about 

Cambria the thickness varies from 40 to 60 feet, the massive lower 

bed occurring in the thicker portions.

The broad table-land about Mount Zion ranch owes its character 

to the underlying Dakota sandstone, as does also the west-sloping 

surface between Oil and Skull creeks. Northwest of Cambria only 

the highest parts of the narrow ridges are capped by Dakota sandstone, but in the vicinity of Ezra the Dakota underlies and causes 

the altitude of the westward slope of the triangular area between 

Mason, Dry, and Skull creeks. North of Mason Creek the Dakota 

sandstone caps the plateau in the east part of T. 49 N., R. 64 W., and 

is found in small patches on the highest parts of the hills between 

Inyankara Mountain and Sheldon. It also caps the ridge between the 

middle and south forks of Hay Creek at Aladdin, Wyo., and forms 

the broad south-facing slope north of Edgemont, S. Dak. In deep 

wells at Edgemont the Dakota seems to be 55 feet thick.

Considerable iron in the Dakota sandstone gives rise to the reddishbrown color of the weathered rock. Much of the iron is in the form 

of small ironstone concretions and sand cemented by iron oxide. 

Fossil plants collected in it show that the age of the Dakota sandstone 

is Upper Cretaceous.

GRANEKOS SHALE.

The youngest formation to be mentioned in connection with the 

stratigraphy of the coal is a fissile shale about 1,000 feet thick which 

rests directly on the Dakota sandstone and is known as the Graneros 

shale. It is moctly dark colored and makes gumbo soil. Within 

abo.nt 200 feet of its base the formation contains a conspicuous band 

of hard shale and thin-bedded fine-grained sandstone which weathers 

L^ht gray and owing to its hardness forms a line of knobs and ridges 

that rise slightly above the main clay slope. This is an extension of 

the Mo wry shale member of the Bighorn Mountains and adjacent 

"regions, and like the Mowry is full of fish scales. Except for these 

the Graneros shale contains few fossils. Its age is lower Benton.

COAL. 

INTRODUCTION.

The coal beds found at a number of places around the Black Hills

in South Dakota and Wyoming are at or near the base of the Lakota

sandstone. The talus of great blocks of sandstone which accumulates

on the Lakota-Morrison contact and the generally wooded condition

19953° Bull. 499 12 2
18 COAL NEAR BLACK HILLS, WYO.-S. DAK.

of the slopes conceal the coal and makes finding it difficult. Natural 

exposures of the horizon are few, and where they do occur the coal 

may have weathered or burned out and the overlying sandstone have 

come down.

It is believed that the Lakota coal beds are commonly lenticular 

and that aside from the deposits at Cambria they cover no great area. 

In some places only one bed of coal occurs, but in a number of others 

a second and smaller bed is found a few feet higher in the section.

The coal of the Black Hills in its best development is a bituminous 

coking grade, but it varies from place to place and in different 

benches of the same bed. Besides coking coal, noncoking bituminous, 

cannel, splint, and "pine-needle" coal are found. (See pp. 49-50.)

OCCURRENCE.

The coal localities in the Black Hills will be described in order 

along the west side of the hills, beginning with the northernmost at 

Aladdin and concluding with those east of Edgemont, S. Dak.

ALADDIN.

Coal was discovered at the north end of the Black Hills on Hay 

Creek about 1875-1880. It was mined by the early settlers, who for 

protection against the Indians lived in a stockade near the site of the 

present store at Aladdin, Wyo. The coal is in two beds in the lower 

part of the Lakota sandstone. The main bed is from 3 to 6 feet thick 

where it has been mined, and the upper bed is about 2 feet thick. The 

beds are separated by 10 to 20 feet of sandy shale. The outcrop along 

the north side of the creek has been thoroughly prospected for a 

distance of 2 miles. West of the store four prospect drifts driven at 

the horizon of the coal bed failed to find coal. One of them at the 

west side of sec. 28, T..54 N., R. 61 W., is said to have been 300 feet 

long. The writer could not verify the absence of coal in this drift, 

which is caved and inaccessible, except by the fact that there is none 

on the dump. A few rods farther west 1 foot of black shale is exposed at this horizon. (See fig. 2.)

Within one-half mile east of the store, along the base of the bluff 

north of the railroad, seven entries and prospects have been driven 

on the coal bed. All are now caved so that the coal bed can not be 

seen. The dumps, mine tracks, and cable used for hauling trips out 

of the mine show that a workable coal bed must have been found 

here; it is said to be 5 feet thick, but the complete abandonment suggests either that the bed was of workable thickness only over a small 

area or else that the coal was not of satisfactory quality.

About a mile east of Aladdin, or near the center of sec. 27, T. 54, N., 

R. 61 W., several openings have been made on the coal. The first,
U. S. GEOLOGICAL SURVEY BULLETIN 499 PLATE III

A. STILWELL COAL CO.'S MINE AND LAKOTA SANDSTONE AT ALADDIN, WYO.

11. LAKOTA SANDSTONE IN CAMP CANYON NEAR CAMBRIA, WYO.
ALADDIN. 19

marked by an air stack, is caved full, but shows coal on the dump. 

The next, at the head of the railroad Y. is caved at 40 feet and only 

the top of the coal bed is exposed. An air course and entry at the 

same point is open for 200 feet, but is supported by square sets and 

lagged so tight that the coal bed-is completely hidden.

The only mine now open at Aladdin is a mile east of the store, on 

the east side of the railroad Y. (See PL III, A.) The main entry was 

driven north down the dip for 1,350 feet and a few rooms were opened. 

Pillars have been drawn from the inner part of the mine and the entry 

is caved full at about 700 feet from the surface. In this distance two 

small faults having an east-west course displace the coal bed to a 

maximum extent of about 15 feet. They may be due to the breaking 

down of the valley wall or cliff formed by the massive sandstones. 

The coal bed in the 700 feet of drift now accessible ranges in thickness

Outcrop of coal 

horizon

Pros peel, no coal Section corner 

found

FIGURE 2. Sketch map of mines and prospects near Aladdin, Wyo.

from 18 inches to nearly 4 feet. At the working face, about 700 feet 

from the mouth, where a section was measured and sample taken, the 

bed is 46 inches thick (see PI. IV, fig. 1, p. 34) and is distinctly divisible 

into two parts. The upper half of the bed is a bright bituminous coal, 

possibly adapted to blacksmithing, and the lower half is hard, dull, 

and bony, with sulphur and iron bands. This lower bench mines in 

hard blocks, whereas the coal of the upper bench crumbles readily. 

In the summer of 1909, when the writer visited Aladdin, coal was 

being mined here every few days for use in a locomotive.

The run-of-mine coal examined at the tipple is composed of small 

pieces of pitch-black, clean, glossy bituminous coal of good appearance, and of blocks or large lumps of hard, ashy coal. These lumps^
20 COAL NEAR BLACK HILLS, WYO.-S. DAK.

which form a considerable part of the output, contain thin bands of 

mineral charcoal, streaks of brown carbonaceous dirt, thin bands of 

clean, bright coal, and nuts of sulphurous clay and iron pyrite. In 

some of these dull lumps the bands or lamellae of bright coal appear to 

be set on edge in carbonaceous shale, and as a result some of the faces 

of these lumps have a rough, pointed, or hackly fracture. In some 

places a thin band of irregularly disposed carbonized fibers, which 

can be ignited individually with a match and will burn freely, is found 

in .the coal.

Analyses of the Aladdin coal will be found in the table on pages 

54-55. They include two samples of the whole bed (1976,1977), one 

each of the upper and lower half (9320 and 9321, respectively), and 

a car sample (2278).

A few rods east of the working mine an entry and air shaft is caved 

full; also an entry of some size, square timbered, and lagged tight, so 

that the bed is not visible. This entry is caved full at 150 feet from 

the mouth and there is no coal on the dump. An entry driven on the 

upper bed at this point is inaccessible. Probably the coal is not thick 

enough to be considered workable under present conditions, as it is 

said to be nowhere more than 2£ feet thick and in most places less.

In the Aladdin folio * Darton states that two of the openings at 

Aladdin were driven northward nearly one-fourth of a mile along the 

coal. He says that numerous prospect holes in the vicinity show 

beds of pure coal which, in most portions of the area, are a foot or 

less in thickness. Little prospecting has been done outside the 

valley of Hay Creek.

Activity in coal mining was greatest from 1898 to 1902, when from 

150 to 200 men were employed. Shipments in 1902 amounted to 

about 10,000 long tons of soft bituminous coal suitable for locomotive 

and domestic use. The output in 1909 was about 60 tons per 

month, or enough to supply the single locomotive of the narrow-gage 

Wyoming & Missouri River Railroad, which connects Aladdin with 

the Chicago & Northwestern Railway at Belle Fourche, S. Dak.

Further evidence of the character of the Lakota coal beds is had 

from North Fork of Hay Creek. According to Prof. Jenney 2 coal 

prospects consisting of a drift run into the hillside about 60 feet and 

two shafts sunk to a depth of 90 feet, 1 \ and 2 miles north of The Forks, 

show four beds of coal, none of which is over 1 foot thick. The relations and thicknesses of these coal beds are as given in the following 

section, which is combined from sections measured at a tunnel and a 

shaft one-half mile apart:

1 Darton, N. H., Aladdin folio (No. 128), Geol. Atlas U. S., U. S. Geol. Survey, 1905, p. 8.

2 Jenney, W. P., Field, observations in the Hay Creek coal fieldjiNineteenth Ann. Eept. U. S. Geol. 

Survey, pt. 2,1899, pp. 584-585.
Section of Lakota coal beds on North Fork of Hay Creek.

	Feet. 

Sandstone, gray, coarse. ......................................... 5

Sandstone, yellow, massive, cross-bedded. ....................... 30

Sandstone, yellow, massive, soft, thin bedded ................... 40

Coal, impure and shaly, at tunnel. ......................... £-f

Shales, drab clay. ............................................. 20

Coal, shaly. ............................................... 1

Sandstone. .................................................... 1

Shale and sandstone, alternating.... . ............................ 12

Coal ...................................................... J

Shale, black. ................................................. 2

Sandstone. .................................................... 3

Coal and shale. ............................................ 1

Clay. ......................................................... 3

Clay shale, black, changing to gray shale at base. ................ 12

Sand rock.... . ................................................. 2

Shale with fossil, plants. .......................................... 2$

Sand rock.... . ................................................. 6

. Morrison clay. 

143

This shows that the coal bed workable at Aladdin does not maintain its thickness in this direction and furnishes confirmatory evidence 

that the Lakota coal beds were .deposited in local basins and are lenticular in outline.

SUNDANCE.

Coal has been found at a number of places in the ridges west of 

Sundance. The nearest occurrence, 4 miles west of the village, is in a 

narrow isolated ridge in the west part of T. 51 N., R. 63 W. Lakota 

sandstone caps the southern end of the ridge. At the southeast 

corner a drift is said to be on a coal bed about 6 inches thick. It is 

reported that the drift is about 100 feet long, and was abandoned 

because the coal did not increase in thickness.

In a flat-topped butte or table 6 miles west of Sundance, in sec. 24, 

T. 51 N., R. 64 W., four drifts have been driven on the coal. (See 

fig. 3.) The first, on the east side of the butte, is reported to have 

been driven 450 feet by Albert Mann, but it is caved now and is 

accessible for about 20 feet only. The coal, under thick cover, is 

said to be 4 feet thick, but not of high grade. A section measured 

by the writer at the mouth 'of the drift shows a roof of soft drab 

shale; an upper bench, ranging from 1 to 2 feet thick, composed of 

a fair bituminous coal streaked with sandstone and bone; 4 to 6 

inches of soft drab clay; and a lower bench of fair bituminous coal 

1 foot thick, but in part bony.

Directly opposite, on the west side of the hill, in the NE. £ NW. \ 

sec. 24, a drift, driven by John Belsher between 1895 and 1900, is 

now caved and inaccessible. It is reported that this drift went
COAL NEAR BLACK HILLS, WYO.-S. DAK.

about 450 feet in a southeast direction and showed approximately 

4 feet of coal. A second drift, on the west side of the hill in the 

NW. | NW. £ sec. 24, was started by Ernest Bolton in the spring 

of 1909, and at the time of the writer's visit early in July of that 

year it had been driven about 100 feet. The roof is hard drab clay 

shale and the floor is hard sandy shale. The coal is in two benches, 

the upper one 17 inches and the lower one 20 inches thick, separated 

by 5 inches of clay. It is a fair-grade bituminous coal and, where 

seen, is only in part bony in the lower bench.

The fourth opening, made by Ernest Bolton in the fall of 1908, is 

at the south end of the hill, in the SE. i NW. J sec. 24. In 1909 this 

____________ drift had been driven about 125 feet north, 

down a slight dip on the coal; it contained 

about 2 feet of water at the face. A slope 

had been started at a lower level for drainage 

and an easier grade for bringing out loaded 

cars. About 30 feet from the entry the bed 

has a thickness of 2 feet 4 inches and is composed of carbonaceous shale and bone with 6 

inches of good bituminous coal near the middle. Mr. Bolton says that at the face of the 

drift the bed shows nearly 4 feet of good coal. 

Bony coal appears on the dump. From 50 to 

75 tons of this coal were sold in Sundance hi 

the winter of 1908-9, but the people who used 

it say the percentage of ash is very high.

The best bed of coal seen by the writer in 

the Sundance region is about 10 miles southwest of the town on Coal Divide. It is reached 

from the Rogers ranch on the Moorcroft road 

in sec. 10, T. 50 N., R. 64 W., by a dim road leading south across the 

meadow about one-half mile to a point on the rim rock and thence down 

to the base of the Lakota sandstone and to an old, abandoned, and inaccessible prospect on the coal. One hundred yards farther west is a drift 

which was opened in the winter of 1908-9 by Steve Pyles and Ole 

Olson and driven about 50 feet with a crooked course. The roof of 

the coal bed is thin-bedded hard drab shale, and the floor is 5 inches 

of hard sandstone underlain by soft clay shale. Four feet of coal is 

found here in a bed divisible into three benches. The upper bench 

is 2 feet of splint with streaks of fine coal; the middle is from 10 to 

12 inches of fine bright bituminous coal; and the lower is 1 foot of 

splint or bony coal with thin bands of shale. (See PI. IV, fig. 4.) 

This coal, like all that in the Sundance region, is high in ash, and 

can not be classed as a high-grade domestic fuel. Darton l mentions

FIGURE 3. Coal area in sees. 13 

and 24, T. 51 N., R. 64 W.

»Darton, N. H., The coal of the Black Hills, Wyoming: Bull. U. S. Geol. Survey No. 200, 1905, p. 433.
SUNDANOE. 23

a tunnel 650 feet long in the SW. 1 sec. 11, T. 50 N., R. 64 W., and 

another tunnel, not in use, in sec. 10, on the opposite side of the 

canyon. This seems to be the same locality as the coal bank opened

FIGUEE 4. Map showing location of Sundance and Mason Creek prospects.

by Pyles &01son and may refer to the two openings already described. 

As this is the only place in several miles where coal has been found it 

can not be stated whether the broad flat-topped ridge known aa Coal 

Divide is underlain by coal or not. Considering the lenticular character
24 COAL NEAR BLACK HILLS, WYO.-S. DAK.

of the Lakota coal beds in other places around the Black Hills it is 

surmised that the extent of the bed here is small. This, however, can 

be determined only by further prospecting along the outcrop and by 

drilling from the plateau above.

MASON CREEK. 

RIDGE WEST OF INYANKARA MOUNTAIN.

Near Sheldon post office on Mason Creek, 16 miles northeast of 

the Chicago, Burlington & Qurncy Railroad at Upton, there are 

several :exposures and prospects on the Lakota coal. Of one of 

these at the western end of a ridge 3 miles west of Inyankara Mountain, in sec. 22, T. 49 N., R. 63 W., Darton 1 says: "On the ridge 

west of Inyankara Mountain it is reported that the coal deposit 

near the base of the Lakota formation has a thickness of 9 feet, 

including a number of layers of shale and bone." This same locality 

was reported to the writer by a resident of the district as showing a 

considerable thickness of workable coal, but examination showed 

that the supposed coal consisted of 9 feet of black and .brown carbonaceous shale containing one or two bands of coal less than one 

inch thick. Near the eastern end of the same ridge, in a saddle which 

cuts through to the Morrison shale, the coal horizon is marked by 

less than a foot of carbonaceous shale.

On the southern end of this isolated block of Lakota sandstone 

the contact between the Lakota and Morrison formations was 

closely examined at two or three points where the exposures are 

good, but no trace of coal could be found. The same is true of the 

block of Lakota lying in sees. 29 and 32, T. 49 N., R. 63 W. The 

horizon was prospected at two or three points (see fig. 4), but only 

a few inches of dark shale could be found.

MILLER COAL MINE.

A small knoll, 2 or 3 acres in extent, on the eastern boundary of 

sec. 29, T. 49 N., R. 63 W., is underlain by coal. This is shown by 

three small prospects in which from 1 to 2 feet of coal is exposed and 

by a small mine on the south side of the knoll, opened and operated 

by Charles H. Miller, of Sheldon, to supply neighboring ranches. 

According to Miller an entry driven 140 feet into the hill passed 

through horsebacks or rolls in the coal bed at intervals of about 30 

feet. This entry has been "gobbed" full and a new one turned to 

the right for a distance of 40 feet. At the head of this second entry 

the coal bed is about 4 feet thick, but it is almost entirely cut out

»Sundance folio (No. 127), Geol. Atlas U. S., U. S. Geol. Survey, 1906.
MASON CREEK. 25

On the left by a roll and 20 feet away by another. The section at 

the head of this drift is as follows:

Section of Lakota coal bed at Miller mine, sec. 29, T. 49 N., R. 63 W.

Roof, black sandy clay. Ft. in. 

Shale, black with fine seams of pyrite.......................... 3

Coal, cannel, solid......................................... 1 8

Shale, black................................................... 9

Coal, cannel, solid......................................... 9

Cleavage line.

Coal, cannel and bone, in 2 to 4 inch bands ................. 1 4

Coal, bituminous.......................................... 4

Clay, black, shaly............................................. 3

Total coal.................................................... 4 8

* Although this section has sufficient thickness, the numerous rolls 

and the small area make the bed of little value, except as here used 

to supply a very few customers. The cannel coal in the above section 

breaks with smooth cleavage faces and has the characteristic velvety 

luster. It burns readily, but carries 23 per cent of ash. (See analysis 

No. 10410, p. 55.) The 4 inches of bituminous coal at the bottom 

of,the bed somewhat resembles ordinary eastern soft coal, being 

composed of bright and dull bands one-eighth to one-fourth inch thick. 

It is reported that in a prospect directly opposite this mine on the spur 

to the south still less coal was found. The prospect is caved, so the 

report was not verified, but half a mile farther south in the NE. I 

SE. \ sec. 29,'an old prospect was reopened and no trace of coal 

could be found, the bed being represented by carbonaceous clay. 

The following section was measured:

Section at prospect near Miller coal mine.

Ft. in.

Sand and sandstone, grayish yellow, thin bedded................. 1 10

Clay, bluish gray, with ferruginous seams ........................ 1 9

Shale, brown, woody........................................... 1

Clay, dark, carbonaceous....................................... 1 10

Clay,bluish gray............................................. 1

Clay, dark, carbonaceous....................................... 2

About one-fourth mile south of this prospect Morrison shale is 

overlain by Lakota sandstone with about 3 inches of brown carbonaceous shale at the contact.

PHILPOTT CANYON.

In the hope of discovering a better coal, Charles H. Miller has 

opened several prospects on or near Philpott Canyon, which empties 

into Mason Creek about 3 miles below Dry Creek. These are on
26 COAL NEAR BLACK HILLS, WYO.-S. 1>AK.

the Lakota bed and reveal the characters already described. One 

of these prospects, near the head of Philpott Canyon a mile above its 

mouth, probably in ihe SW. £ NE. £ sec. 23, T. 49 N., R. 64 W., is in 

the west bank 50 feet from the stream in the edge of timber one-half 

mile below the J. B. Roche homestead claim. The drift, which has 

been driven 10 or 12 feet through soil to bedrock, shows a bright black, 

flaky, dirty coal, as follows:

Section in upper Philpott Canyon.

Ft. in. 

Sandstone, Lakota.................. e..........................

Clay, drab and brown........................................... 6

Coal, dirty, flaky, bituminous ?............................ 1 7

Shale, carbonaceous; weathers brown............................ 1 8

Shale, floor.

A few streaks of bright coal appear in the lower part of the 20 

inches of brown shale. Nothing about the prospect suggests that 

the coal will be thicker under the hill.

Farther down Philpott Canyon in the second small draw above the 

mouth, on the north under a sandstone ledge, two coaly bands are 

separated by 18 inches of sandstone. The upper band is 1 foot thick 

and the lower one 20 inches to 2 feet thick. Both appear to be a 

mixture of black clay and pressed mineral charcoal and also differ 

from the true Lakota coal in that they soil the hands very markedly. 

Not only are these bands too thin to be worked but also they are 

apparently not true coal.

On another branch of Philpott Canyon, the following section was 

measured at a small prospect in the Fuson shale:

Section at prospect in Philpott Canyon.

Ft. In.

Sandstone, carbonaceous, with £-inch seams of coal and nodular

ferruginous layers.......................................'..... 1 10

Clay, gray. ................................................... 10

Sandstone, argillaceous, yellow and gray........................ 1 10

Shale, sandy to sandstone, argillaceous........................... 1 8

Shale, slaty gray.............................................. 3

Coal, bony at bottom....................................... 9

Shale, carbonaceous, with J-inch streaks of coal................... 1 7

Clay, gray.................................................... 1

Shale.

The largest prospect in the vicinity is 15 feet above water in the 

west bank of Mason Creek opposite the mouth' of Philpott Canyon, 

3' miles below Dry Creek. It is driven west about 15 feet under 

massive Lakota sandstone.
SKULL CREEK. 27

Section at prospect on Mason Creek opposite Philpott Canyon.

Ft. in. 

Sandstone, buff, massive; a ledge maker....................... 15

Sandstone, white, shaly....................................... 3

Clay, white.................................................. 6

Coal, flaky, dirty; resembling charcoal...................... 1 6

Clay, dark drab with carbonaceous flakes........................ 3

Clay, white with carbonized roots............................. 4 9

Coal, flaky, dull, square cleavage; resembling charcoal........ 1 1

Shale, black, carbonaceous..................................... 1

Shale, dark................................................... 3

Sandstone.

It is apparent from the foregoing section that although there is 

sufficient coal here to raise the hopes of the prospector, there is little 

to encourage development.

DRY CREEK.

The energy that may be expended on a small showing is illustrated 

by a prospect in the bank of Mason Creek, just above the mouth of 

Dry Creek, where a drift 80 feet long and well timbered at the mouth 

has been driven on a thin bed of carbonaceous shale. The section 

is given below:

Section at prospect near mouth of Dry Creek.

Ft. in.

Shale, sandy, with sandstone layers............................ 3

Sandstone, ferruginous......................................... 1 1

Sandstone, argillaceous, iron stained............................ 5 8

Shale, drab................................................... 1 11

Sandstone, gray, £-inch concretionary iron bands near base........ 3 9

Clay, sandy.................................................. 9

Sand, gray................................................... 6

Sand and clay................................................. 7

Clay, gray................................................... 11

Sandstone, yellowish, thin bedded.............................. 1

Shale, carbonaceous, hard and brittle, with lenses of gray clay.... 4-10

Clay, streaked white and gray................................. 7

Shale, clayey, black, carbonaceous. .......................... 11

Clay,light gray.............................................. 6

This section is in the Fuson shale, which in this vicinity carries 

carbonaceous shale beds and in places a little coal.

SKULL CKEEK.

In T. 48 N., R. 63 W., the writer did not find any trace of coal. 

The horizon was examined in the detached block northwest of the 

Holwell ranch and on. the road crossing the escarpment between
COAL HEAR BLACK MILLS, WYO.-S. DAK.

Ezra and Holwell's, but without success. It is reported by W. E. 

Holwell that some years ago a shaft and drill holes were sunk to the 

coal horizon from the top of the table in section 22, but that no 

coal over a foot thick could be found.

Lakota coal of workable thickness occurs in the vicinity of the 

Holwell ranch on Skull Creek, about 30 miles northwest of Newcastle, 

and has been opened by drifts at three or four places. That this 

increased thickness is local, however, is shown by prospects and 

outcrops in the immediate vicinity which do not disclose coal. The 

main openings on this coal are 1£ miles southeast of the Holwell 

ranch, in the SE. i SE. i sec. 31, T. 48 N., R. 62 W. (See fig. 5.)

R.63W. R.62W.

T48N.

T.47N.

Roads Coal horizon 

FIGURE 5. Sketch map showing location of prospects at Holwell ranch, northwest of Newcastle, Wyo.

At the heads of two ravines in the woods on the steep bluff formed 

by the massive Lakota sandstone there are two drifts about 500 feet 

apart. The easternmost, or Holwell No. 1, has been driven south 55 

feet. The rocks at this point dip southwest about 2°. From the 

Rurface to the breast the thickness of the coal bed increases about a 

foot. The section of the coal at the face of the drift is as follows:

Section at Holwell coal bank No. 1.

Sandstone roof.

Clay, drab, soft.

Bone (analysis 6744, p. 54).................................

Coal, bituminous, with ashy and bright streaks............ 2

Coal, bituminous, bright (analysis 6746, p. 54).............

Coal, cannel (analysis 6743, p. 54)......................... 1

Coal, bituminous, bright (analysis 6746, p. 54)............. 1

Coal, cannel................-.....-.-...-.-- --.-.------ 1

Coal, bony, shaly; burns well............................

Sandstone. 

Ft. in. 

1 2
SKULL CREEK. 29

A section at the Hoiwell No. 2, about 500 feet farther west, shows 

a decreased thickness in the bed and is as follows:

Section at Hoiwell coal bank No. 2.

Ft. in.

Bone....................................................... 6

Bone, with streaks of bituminous coal........................ 1 1

Coal, bright, bituminous................................ 3

Coal, bony.............................................. 8£

Coal, bright, bituminous................................ 2£

Coal, bituminous, dull................................... 5J

Coal, cannel........................................... 5 

Coal, bony.............................................. 1$

Coal, bright, bituminous................................ 9

Coal, splint............................................ 1

Bone....................................................... 6

Analysis 6745, p. 53, is from a sample taken in this prospect. 

The drift at this second bank was driven south 55 feet and then 

turned southeast 40 feet. It is timbered and lagged tight to hold 

the soft clay roof. The floor is hard, flinty ironstone resting on 

massive white sandstone.

Both drifts are dry and are in good condition for examination. 

Very steep wagon trails lead to both of these drifts, but that to 

No. 1 has been so long abandoned that it is overgrown with brush 

and partly obliterated by talus. Analyses (see p. 54) have been 

made of samples taken from the whole bed at each of tfhese two 

openings and separate analyses of the cannel, bone, and best coal 

at Hoiwell No. 1.

About 1,000 feet east of Hoiwell No. 1, close to the line between 

sees. .31 and 32 and a little south of the east quarter-section stone in 

the timber on the steep hillside, a small prospect, opened directly 

under the Lakota sandstone, revealed the following section:

Section 1,000 feet east of IJolwell No. 1.

Ft. in.

Clay, drab, and shale, brown................................. 1

Coal, ashy, with bituminous streaks....................... 10

Sandstone, white, soft, with streaks of carbon.............. 5

Coal, bituminous, good quality........................... 2 4

Quartzite, gray, mottled with white. 

4 7

No trace of coal has as yet been discovered east of this small 

prospect or west of Hoiwell No. 2. In fact, at the point of the spur 

over which a wagon road leads from Hoi well's ranch to the tableland, and close to the range line at the northwest corner of sec. 31, 

the horizon is well exposed and shows several feet of black and brown 

shale without coal.
30 COAL NEAR BLACK HILLS, WYO.-S. DAK.

It is reported by Mr. Holwell that two churn drill holes put down 

by his sons in sec. 36, T. 48 N., R. 63 W., found only a little black 

mud at the coal horizon, and that a shaft near the southeast corner 

of the same section went -through the Lakota sandstone into the 

Morrison shale without finding coal.

A shaft sunk at the east quarter corner of sec. 1, T. 47 N., R. 63 

W., in the summer of 1908 by Mr. George S. Jackson, of Deadwood, 

S. Dak., is at the. base of a spur at the head of the middle fork of a 

small stream which flows west through section 1. The shaft is 6 

feet square, timbered, and passes through 59 feet of Lakota sandstone. 

In hopes of finding the Lakota coal, it was continued below the sandstone for nearly 50 feet. The only trace of coal, however, was from 

9 to 15 feet below the sandstone, where nodules of iron pyrite were 

found, carrying fragments of coal. These two shafts and two drill 

holes indicate the nonoccurrence of the Lakota coal in this vicinity.

Coal is present, however, near the center of sec. 12, T. 47 N., R. 63 

W., and is exposed in the bed of a ravine. Two drifts have been 

opened, one in the north and one in the south bank. These are 

on land patented by J. C. Spencer, and will be called the Spencer 

prospects. The drift in the north bank is only 10 feet long and shows 

the following section:

Section at Spencer prospect, north bank.

Ft. in. 

Shale, brown to black; changing to shaly sandstone............. 4

^Dannel, glossy below, dull above, upper half platy, lower

half closely checked................................... 1 2

Shale, brown, carbonaceous............................... 3

Coal, bituminous........................................ 1

Shale, brown, carbonaceous............................... 4

Coal, bituminous, fair quality............................. 4

Bone, deep weathered with laminae of bituminous coal ..... 1 1

Ironstone floor. 

Total coal bed........................................ 3 3

The drift in the south bank has been driven south 110 feet, and 

discloses the section here given:

Section at Spencer prospect, south bank.

Ft. in. 

Shale, brown to black..................................... 4

Coal, splint........................................... 9

Coal, splint, very ashy................................. 3

Bone.................................................. 11-14

Coal, bituminous with pyrite nodules................... 2 2

Ironstone floor. 

Total coal bed....................................{ ^ J

A shaft sunk to the coal horizon a few rods north of the Spencer 

prospects found the bed diminished in thickness. At an abandoned 

and partly-filled shaft a few hundred yards up the ravine there is
PLUM CREEK. 31

nothing on the dump to indicate that coal was found. An examination of the outcrop in Black Canyon and on Oil Creek, both by the 

writer and by prospectors during the past 20 years, has failed to discover any point where this coal bed is over a foot thick.

This evidence as to the occurrence of coal in the vicinity of the 

Holwell ranch suggests that, although the coal bed is of workable 

thickness at two or three places, this character probably continues 

only a short distance. The development of a mine here should be 

preceded by thorough drilling to find the extent of the coal.

.PLUM CREEK.

The outcrop of the Lakota sandstone on both branches of Plum 

Creek has been prospected for coal during the past 15 years, practically without success. So far as known the only showings of coal 

are in two prospects near the head of East Plum Creek. One of these, 

at the head of the fork in sec. 18, T. 46 N., R. 61 W., is as follows:

Section of coal bed on East Plum Creek.

Ft. in.

Shale, carbonaceous.......................................... 8

Coal...................................................... 8

Sandstone............................................... 1

Coal, dirty, containing sand................................ 1 8

Coal, slightly sandy...................................... < 5$

Sand, with 1-inch lenses of coal............................... 2 2

6 7*

This coal appears to be of too poor quality for mining. 

On the opposite side of the stream in sec. 12, T. 46 N., R. 62 W., 

another exposure of this bed shows the following section:

Section of coal bed on East Plum Creek.

Ft, in.

Coal, impure.............................................. 8

Coal, good................................................ 7|

Coal, bony................................................ 10

Coal..........................................:........... 6

Shale, sandy................................................. 1 4

Ceal...................................................... , 2£

Coal, bony................................................ 1 1

5 3

The bed is thick enough to mine, but only a small part is good coal.

Openings made at the base of the massive sandstone below the forks 

of Plum Creek do not show any coal. The coal horizon is rarely 

exposed because of the heavy talus from the overlying sandstone, 

but at the few natural exposures examined by the writer the coal was 

not found. Not only is this true of the canyons cut in the plateau, 

but also of the escarpment on the west of Salt Creek. Here the coal
32 COAL NEAR BLACK HILLS, WYO.-S. DAK.

horizon is almost completely hidden and but one exposure was seen. 

This is in the N. \ sec. 17, T. 46 N., R. 61 W., and shows a thin bed, 

possibly an upper one above the main Lakota coal bed.

Section of coal bed west of Salt Creek, near Salt Spring.

Ft. in.

Bone, shaly.................................................... 5

Coal....................................................... 5

Coal, bony or cannel...................................... 6

Coal....................................................... 3

1 7

If this is a complete section of the bed mined at Cambria, it shows 

that the limit of workable coal is not so far north as mapped in the 

Newcastle folio (No. 107), and suggests the possible absence of the 

coal in the Northwest Table and in Sweetwater Mountain.

It can not be said that there is no coal in the ridges between Black 

Canyon and the head of Salt Creek, but none of any value has been 

found in 30 years. The only indication in this part of the field is a 

4-foot bed of black, coaly shale discovered by the writer in a landslip 

about 1$ miles southeast of the T E ranch. The weathered outcrop 

did not permit an exact determination of the character of the material, 

but it did not appear to be good coal. An effort to find the bed in 

place was unsuccessful.

CAMBRIA. 

HISTORY.

The discovery of coal in the vicinity of Cambria is variously reported 

at dates ranging from 1877 to 1886. The field was first thoroughly 

prospected in 1886, and discoveries made which called attention to 

the possibilities of the Black Hills as a source of fuel for a railroad 

crossing the northeast corner of Wyoming. The Burlington & Missouri River Railroad, which was then completed to Grand Island, 

Nebr., offered to build on west across Wyoming if a sufficient supply 

of coal could be had.

Kilpatrick Bros., of Beatrice, Nebr., tested the field at Cambria 

with diamond drills and started entries in 1889. The main line of 

the Burlington was extended into Wyoming, with a spur from Newcastle to Cambria, and the first car of coal was loaded in December, 

1889, in which month 2j700 tons were shipped.

The mines were opened by Kilpatrick Bros. & Collins and operated 

by them under the name of the Cambria Mining Co. until December 

31,1902, when possession was transferred to the Cambria Coal Mining 

Co., which carried on operations during 1903. In February, 1904, 

the property went back to the original owners, who reincorporated 

as the Cambria Fuel Co. and are the present owners of the property.

Cambria is the only place in the Black Hills where the Lakota coal 

has proved of workable thickness over more than a few acres. Here
CAMBRIA. 33

it is workable through a considerable part of 12 square miles. Extensive mines are operated by the Cambria Fuel Co., the only producers 

and shippers in the Black Hills.

MINES AND METHOD OF MINING.

The coal near Cambria lies practically flat 200 to 300 feet below the 

surface of a plateau, which is deeply dissected by Camp and Coal 

canyons and their branches. It outcrops in the canyon walls 50 or 

60 feet above the bottoms so that the mines have plenty of tipple and

p.eaw. R.6IW.

FIGURE 6. Extent of mine workings at Cambria, Wyo.

waste room. The coal bed in the Cambria mines varies normally 

from 3 to 10 feet in thickness, has a hard sandstone roof and floor, 

and is free from gas and water. - ,

On account of their separation by these canyons the different mining 

operations are considered as separate mines, as shown on the map 

(fig. 6).

The Jumbo mine is situated on the east of Coal Canyon and extends 

through to the rim wall or escarpment on Salt Creek, a distance of 

3,400 feet. The north and south length of the mine is about 8,000 

feet.

 19953° Bull. 490 12 3
34 COAL NEAR BLACK HILLS, WYO.-S. DAK.

North Opening is the name of the mine lying between the forks of 

Coal Canyon. Its main entry has been driven east to connect with 

the north workings of the Jumbo mine.

Antelope mine No. 1 is between Camp and Coal canyons. Through 

it passes a tunnel 3,200 feet from portal to portal, by which Antelope 

No. 2 on the west side of Camp Canyon is reached. Haulage between 

the two mines is maintained over a 400-foot trestle about 85 feet 

high, which spans Camp Canyon. (See PL III, B, p. 18.)

Antelope mine No. 2, which lies entirely west of Camp Canyon, has 

a length of about 6,800 feet and an average width of 2,000 feet.

The main entry to Antelope mine No. 3 is about three-fourths of a 

mile northwest of Cambria on the west side of Camp Canyon, well 

toward its head. It is reached by a long tunnel driven from the main 

entry in Antelope No. 1. ,Camp Canyon is crossed by a trestle about 

a mile above that connecting Antelope Nos. 1 and 2.

Antelope mine No. 4 is on the east side of the head of Camp Canyon 

and is the latest development. It is reported that the recent work in 

this mine has opened up a fine body of coal, and it is presumed that 

for the present work will be pushed in its direction.

All haulage from Antelope mines Nos. 2, 3, and 4 is through Antelope No. 1, and delivery is made at a single tipple on the east side of 

Coal Canyon, over about 50 miles of 42-inch gauge track. Kails 

weighing 25 pounds to the yard are used in the main entries and 

16-pound rails in the side entries and rooms.

The room-and-pillar method of mining is used, except in a few 

districts where the thinness of the bed makes the long-wall system 

more economical. Mining is done by subdistricts composed of a 

minimum of 10 rooms. After all the rooms in a subdistrict areworked out the inside pillars are drawn, leaving the chain pillars to 

protect entries. Early in the development of these mines the rooms 

were opened 40 feet wide, but this was found to be too great a width 

for safe working and 24 feet Was adopted as giving the best results. 

The single-entry system is never used in these mines.

The coal is all cut by machine, being too hard for hand mining. 

Nearly all of the underground work is done on the contract system, 

the men being paid a certain price per car, varied to suit the conditions 

of the work at each place.

CHARACTER OF THE BED.

The coal is hard bituminous, with bands of dull coal, locally called 

splint and cannel. In places the bed is solid coal, in others it is separated into two or three benches by clay or sandstone partings. (See 

PL IV.) The following sections show the thickness of the coal bed in 

five districts of the mines at Cambria as reported to the company by 

the secretary, L. T. Wolle, in 1908, and by E. H. Lawall, M. E., of
U. S. GEOLOGICAL SURVEY BULLETIN 499 PLATE IV

46"

16

86"

EXPLANATION

Coal Impure or Bone Cle Shale Sandstone

"bony coal

Numbers on right of sections give thickness of coal 

Numbers on left of sections give thickness of -waste 

Vertical scale linch = 5 feet 

LIST OF MINES AND PROSPECTS

ALADDIN 7-9. HOLWELL 17-18. CAMP CANYON 27. GRANT CANYON 

BOLTON 10-11. SPENCER 19-23. ANTELOPE 2 & 3 28-29. NEWCASTLE 

ROGERS 12-13. E. PLUM CR. 23. JUMBO 3O. ROBBERS ROOST 

MILLER 14. SALT SPRING 24-2S. ANTELOPE 1 31. COAL CANYON

MASON CR. 15-16. ANTELOPE 3 & 4 26. MT. ZION 32-34. CHEYENNE R.

SECTIONS OF COAL BEDS NEAR BLACK HILLS.
CAMBRIA. 35

Wilkes-Barre, Pa., in 1902. Wolle's figures were obtained by computation from area worked out and actual tonnage yielded and do not 

include splint that was "gobbed." Lawall's figures are averages of 

the thickness of the bed as actually measured in the mine. Averaging 

all the measurements proportionally to the area of the respective 

mines gives an average thickness of about 5 feet for the bed as exposed 

in the underground workings.

Average thickness of coal bed in Cambria mines.

Mine.

Antelope No. 3 .................................................................

Wolle.

' Ft. in. 

5 8

4 8

4 2

4 8

4 2

La wall.

Ft. in.

5

Q3

4 83

4 3f

4 10|

In some places in Antelope No. 3 and No. 4 the thickness of the 

bed is considerably above the average, as shown by the two following 

sections measured by W. E. Mouck, superintendent of the mines:

Section of coal bed in fifth west entry, Antelope mine No. 3.

Ft. 

Coal, good (bituminous)................................... 1

Coal and sandstone...........................................

Coal, cannel................................................ 2

Coal, good...................................................

Coal, splint, good............................................

Coal, good................................................... 1

Coal, splint, good.............................................

6 11

It is understood that in 1909 the company opened up in Antelope 

mine No. 4 an excellent body of coal, which is in some places 10 feet 

thick. (See PL IV.) The section below gives the details of the bed 

as it commonly occurs in this mine:

Section of coal bed in first east entry off main south entry, Antelope mine No. 4.

Ft. in. 

Coal, good (bituminous)...........:.......................... 1 6

Coal, splint, good........................................... 2

Coal, good................................................... 4

Coal, splint, coarse........................................... 1

Coal, good.................................................... 6

Coal, medium................................................ 2

Coal, good................................................... 8

Coal, medium................................................ 1

Coal, good................................................... 3

^ Coal,splint, good........................................... 2

Coal, good................................................... 6

9
36 COAL NEAR BLACK HILLS, WYO.-S. DAK.

The thickness of the bed varies with the position of the floor, which 

is slightly wavy, and also with the thickness of the partings. This 

is shown at the head of Camp Canyon in entries on the east and west 

sides of the stream.

Sections of coal bed in Camp Canyon.

Section.

Coal........................................................................

Coal........................................................................

East.

Ft. in. 

3

7

2 3

5 10

West.

Ft. in. 3 8

4

3 3

10 11

The east section was measured about 180 feet from the entry, and 

the west section 200 feet from the entry. In driving the main entries 

in Antelope mine No. 3 to this entry from the west side of the canyon 

it was found that the 4-foot sandstone parting is only of very small 

lateral extent.

In places in the Cambria mines the Lakota coal is so thin and bony 

that its mining is not at present profitable. Two sections measured 

6 feet apart in room 104 of No. 6 west in Antelope mine No. 2 are 

given below:

Sections of coal bed in Antelope mine No. 2.

Sandstone, white, soft, roof.

Coal, bituminous, bright, 

solid....................

Clay, drab, soft............

Coal, bony, very hard......

Coal, bituminous, bright...

Coal, bony, hard...........

Coal, bright................

Sandstone floor.

4 2

About 300 feet due west from room 104 the following section was 

measured:

Section of coal bed at roll in Antelope mine No. 2.

Sandstone roof. Ft. in.

Bone with bright coal streaks................................. 3

Clay in lenses............................................... 0-2

Coal, mostly bright, with bony streaks..................... 7

Clay, hard............................................... 4

Coal, bright......................................:....... 4

Bone.....;.............................................. 6

Coal, bright.............................................. ' 11

Bone, with streaks of bright coal.......................... 12

4 1

Ft.

2

in.

12 

4 

5 

8 

2 

1-2

8

Sandstone roof. 

Sandstone, brown, carbonaceous.

Coal, bituminous, bright.... 

,Clay, drab, hard. ...........

Coal, bituminous, bright. . . . 

Clay......................

Coal, bituminous, bright.... 

Bone and coal. ............

Ron Hat/mo flnnr

Ft. in. 

i-3 

10 

4 

5 

8 

10 

1 

2 

7
CAMBRIA. 37

This section is on a roll which has an east-west strike and dips 50° 

to 60° S. Although the bed is thin here, it is possible that the roll 

has no great width and more workable coal lies beyond it. The bed 

at this point is mined by the long-wall method.

The thickness and character of the coal bed in the Cambria mines 

is further illustrated by the following four sections measured by 

Frank W. DeWolf in different parts of the mines. 1 Section A was 

measured in room 6 off the third northwest entry in Antelope No. 3 

mine; section B, in room 9 off the eighth northwest entry in Jumbo 

mine; section C, in room 7 northwest in Antelope No. 1 mine; and 

section D, in room 14 in Antelope No. 1 mine.

Sections of coal bed in the Cambria mine, Cambria, Wyo.

Section A.

Sandstone. 

Coal........................

Coal, splint. ...............

Coal........................

Coal........................

Coal, splint. ...............

Coal........................

Coal, splint. ...............

Section B.

Shale, black. 

Coal (cannel?). . ............

Coal........................

Coal, splint. ................

Coal........................

Clay.......................

Coal........................

Coal, splint. ................

Coal.........................

Coal, splint. ................

Coal........................

Clay.......................

Coal.........................

»

Ft. in. 

.. 2

7

6

2

.. 1 10

10

6

3

ft 8

Ft. in. 

2

2

7

10

li

q

K

q

4

2

.. 1

5 6

Section C. 

Sandstone. 

Shale, black. ................

Clay.......................

Bone........................

Clay.......................

Coal.....:./.............

Sulphur ................

Coal.....................

Clay...................

Coal.....................

Total coal............

Section D.

Sandstone.

Shale.......................

Bone............. ...........

Coal, splint. ............

Clay...................

Coal.....................

Total coal... -----....

Ft.

.. 1

.. 1

.. 1

.. 1

.. 1

.. 4

Ft.

.. 1

.. 2

.. 3

ID.

4

5

3

5

1

91

01

7

'in.

3

7

2?

1

9

1

Analyses Nos. 1376, 1377, and 1571 (p. 53) represent samples taken 

during the process of testing this coal at St. Louis during the Louisiana 

Purchase Exposition. Nos. 1376 and 1377 represent the coal at the 

places where sections A, B, and C were measured, and No. 1571 represents a carload shipped to the testing plant. Analyses 6790, 6792,

1 Eeport on the operations of the coal-testing plant of the United States Geological Survey at the Louisiana Purchase Exposition: Prof. Paper U. S. Geol. Survey No. 48, pt. 1, pp. 139-140.
38 COAL NEAR BLACK HILLS, WYO.-S. DAK.

and 6793 were taken by the writer and represent different grades of 

coal from these mines.

Mining has been discontinued where the bed is less than 3 feet 

thick, but drilling in advance of the breast has-proved that under a 

considerable area as yet undeveloped the bed is from 4 to 8 feet thick.

VILLAGE AND MINE EQUIPMENT.»

By C. T. LUPTON.

POPULATION AND BUILDINGS.

Cambria is a small village located in the bottom of the canyon of 

Little Oil Creek on a branch known as Coal Canyon. It is distinctly 

a mining camp, having been built up and developed by the Cambria 

Fuel Co. around the coal-mining plant. . The population naturally 

consists entirely of officers and miners employed in coal mining. 

Between 400 and 450 miners, mostly foreigners, are constantly 

engaged at the mine and with their families make a population of 

about 1,400 persons. The Cambria Fuel Co. owns a large area of 

land in the vicinity and has complete control of the village and its 

surroundings. Besides its two-story office building, located at the 

forks of the canyon in the middle of the village, and the necessary 

mine houses, the company has constructed about 150 modest but 

substantial frame houses for the use of the miners. Most of these 

houses, together with two or three churches, are located in the bottom 

of the canyon. (See PI. V, B.)

As the population increased, a little settlement known as Antelope 

City was built, in 1892, on the plateau above the tipple at Cambria. 

This consists of 31 small frame houses and a large two-story schoolhouse. The school children, by this arrangement, spend a greater 

part of the school days away from the noise and traffic of the main 

village and in the purer air of the plateau.

The miners' houses are supplied with running water from a gravity 

system built by the company and are lighted with electricity. Many 

of them also are supplied with steam heat.

The company owns and operates the only store in the village, and, 

through it, supplies all the demands of miners and ranchmen in a 

radius of several miles for merchandise and provisions. By means of 

its large land holdings the company is able to prohibit the sale of 

liquor at the mines, the nearest saloon being at Newcastle, about 8 

miles distant. Because of this arrangement, and also on account 

of the fair treatment accorded the miners, the company has had no 

trouble with strikes or other disturbances so common in mining towns.

The mining company operates a large hotel for the benefit of those 

who prefer it to a separate residence or boarding house. It also

i Fart of the information here presented is derived from the paper by Chenhall, listed on page 6.
U. S. GEOLOGICAL SURVEY

A. CAMBRIA FUEL CO.'S TIPPLE AT CAMBRIA, WYO.

H. VIEW OF CAMBRIA, WYO.
CAMBRIA. 39

maintains a small but well-equipped hospital (the only one in Weston 

County) .in charge of a physician and a trained nurse.

For the daily use and convenience of the miners the company also 

maintains a bathhouse fitted with a large number of individual washbowls, with hot and cold water, shower and tub baths, and lockers. 

This feature of the mining camp is greatly appreciated by the men 

and may in part account for the pleasant relations between employers and employees.

RAILROAD FACILITIES.

Cambria is the northern terminus of a branch of what was formerly known as the Burlington & Missouri River Railroad but is 

now the Chicago, Burlington & Quincy Railroad. The branch is 7.8 

miles long and connects Cambria with the main line at Newcastle. 

It is a single-track railroad built along the valley bottom, with a 

necessarily heavy grade, which favors the loaded coal cars. All 

necessary yardage has been constructed at Cambria, so that supplies 

are unloaded directly at the warehouse, and the loading tracks pass 

beneath the tipple. There is sufficient room above the tipple for 50 

or 60 cars.

WATER SUPPLY.

Cambria derives an abundant supply of excellent water from 

Sweet water Mountain, Mount Pisgah, and a deep well.

Sweetwater Mountain, which lies 6 miles north of Cambria, is so 

named because its numerous springs are not alkaline. Water from 

several springs on the east side of the mountain is piped to a main 

line which carries it around the face of the escarpment on the west 

of Salt Creek to the Jumbo Tunnel at its eastern end, through the 

Jumbo mine, and into a large covered reservoir below the mouth 

of Grant Canyon. This lower reservoir constitutes the supply for 

the city of Newcastle. On emergency, the water can be turned 

into an upper reservoir and used for the boilers and the compressedair cooler.

Mount Pisgah is 4 miles northeast of Cambria, on the east side 

of the deep valley of Salt Creek. Curious as it may seem, there 

are a number of springs at the base of the Lakota sandstone close 

to the top of the mountain. The water from some of these springs 

is piped by gravity across the valley of Salt Creek and over the 

ridge at the road gap to Cambria, where it furnishes sufficient pressure for excellent fire protection. Water from this system is stored 

in an open cement-lined reservoir at the upper end of the village. 

The supply from this source is estimated from 30,000 to 40,000 

gallons daily.

A well just above the tipple at Cambria was drilled to a depth 

of 2,345 feet and obtained a strong flow of water about 2,115 fee.t
40 COAL NEAE BLACK HILLS, WYO.-S. DAK.

below the surface, in the Pahasapa limestone. This water, which 

is of excellent quality, rises under artesian head to within 500 feet 

of the surface and is reported to yield at least 200 gallons a minute. 

In fact, it is said that in a test which lasted more than two hours 

the well was pumped at the rate of 225 gallons a minute without 

lowering the level of "the water.

A unique method of pumping, devised by the superintendent, 

W. E. Mouck, is used at this well. An 8-inch casing to 900 feet 

cuts off alkaline water. Inside this is a 5J-inch (outside diameter) 

pipe extending down about 2,000 feet. This pipe is carried above 

the surface to a tank situated on the hillside 160 feet above the 

well mouth. A pipe 1 inch in diameter for about 1,200 feet and 

f inch for 480 feet more, with end turned up and opening reduced 

to f inch, carries compressed air about f^700 feet below the mouth 

of the well, or about 1,200 feet below the surface of the water. This 

pipe enters the inside pipe at the well mouth with a tight joint. 

When it is desired to fill the tank, compressed air is discharged 

through this small pipe with a pressure of from 700 to 800 pounds 

to the square inch. The result is that the water is discharged into 

the tank in a 5-inch column with considerable violence. The pressure of the water when the tank is full is between 63 and 73 pounds 

per square inch on the gages in the compressor room. This pressure 

is sufficient to furnish excellent fire protection for the mine buildings. 

Antelope City, which is situated on the plateau above, is supplied 

with running water from a tank, which is filled by steam pump from 

the lower tank on the hillside.

The village is equipped with two hose carts which carry a large 

reel of 2$-inch hose, and, as described above, the gravity pressure 

in the pipe lines is sufficient to throw a strong stream. Besides the 

water system, the company buildings and the- mines are supplied 

with several dozen portable chemical fire extinguishers.

MECHANICAL EQUIPMENT.

Workshops. At the lower end of the village and along the west side 

of the railroad the company maintains substantial frame buildings for 

the power plant and for workshops. The latter are equipped not only 

for making all repairs needed at the mines, .but also for constructing 

any special machinery that may be needed. Although the available 

land adjacent to the mine entries is small, the buildings are all located 

conveniently to the tipple, the mine entries, and the railroad track.

Mining machinery. The power plant at the Cambria mines included in 1908 a battery of nine boilers. This battery consists.of 

three Heine boilers of 300 to 350, 375 to 425, and 425 to 525 horsepower capacity; three Drake, Wilson & Williams boilers and two
CAMBRIA. 41

Kewanee boilers of 150 horsepower each; and one marine boiler of 125 

horsepower capacity. This gives a total of 1,975 to 2,175 horsepower. 

, The boilers are fed with fine slack and unmerchantable coal derived 

from the screens. They are fired by three shifts of six firemen each. 

Automatic stokers were used for a time but have been withdrawn 

becauss they were not so successful as hand firing.

As the coal in the Cambria mines is too hard to cut by hand all 

mining is done by power machines. The system used is compressed 

air, and the mine plant is equipped with six compressors of the following make: One Ingersoll, 70 to 85 pounds pressure, made by the 

Ingersoll-Rand Co., New York; three "low pressure," 70 to 100 

pounds, made at South Norwalk, Conn.; and two "high pressure," 

750 to 1,000 pounds, made at South Norwalk, Conn. These compressors, which distribute compressed air throughout the mines by 

the usual piping system, operate coal cutters and drilling machines 

and also furnish power for air motors used in collecting cars from the 

rooms and making up trips. Nine Porter air motors are in use, 

seven of them in Antelope mine No. 3 and two hi Antelope mine 

No. 2, as follows: Five 7-ton motors, one 15-ton, and three 5-ton.

The company has seventeen H4 and seven G2 Ingersoll-Hand 

punchers in use in the mines, besides two Harrison punchers, twelve 

G2 punchers, and three H4 punchers, that are not in use. The H4 

has proved to be the better machine for this hard coal.

The coal is hauled from both the Antelope and the Jumbo mines by 

the tail-rope system. An engine Ipcated at the mouth of Antelope 

mine No. 1, which is close beside the tipple, has 500-horsepower 

capacity and operates a haulage system 1£ miles long. The engine, 

which is of the first motion clutch type, was built at the Ottumwa 

Iron Works, Iowa; the cylinders are 24 inches by 34 inches and the 

drum 5 feet hi diameter and 5 feet wide between the flanges, which 

are 6£ feet in diameter. The capacity of the drums is 2£ miles of 

f-inch wire rope. The trips from this mine consist of 39 cars, each 

with a capacity of about 3,600 pounds of coal.

At the Jumbo mine a haulage engine is located about 300 feet in 

from the entrance. It was built by the Nelsonville Foundry & 

Machine Co., of Nelsonville, Ohio, and may be described as a doubledrum engine, geared five to one, with two cylinders 16 inches by 24 

inches, the drums being 6 feet in diameter and 2 feet 6 inches wide 

between the flanges, the latter being 12 inches deep, with a capacity 

for holding about 1£ miles of 1-inch wire rope on each drum. The 

average trip consists of 20 trip cars, each weighing about 1,800 

pounds and containing about 4,000 pounds of coal. The trips are 

hauled by a steel-wire rope, 1 inch in diameter, of six 9-wire strands. 

A rope of this diameter with nine wires to the strand and the Lang lay 

has been found to give longer service than one with seven wires and
42 COAL NEAR BLACK HILLS, WYO.-S. DAK.

the regular lay. The main line takes the trip in to a distance of 

3,000 feet, the rope passing around a 6-foot bull wheel placed under 

the track. About 1,500 feet beyond this a second engine, located at 

the top of the second grade in the mine, takes the trip up the second 

grade, from which point the cars are distributed through the mine by 

horses and mules. The second system has about one-half mile of 

cable. The trips coming out from the mine are delivered by the 

rope at the beginning of the trestle and let down by gravity to the 

tipple. After being dumped, the cars run by gravity to the foot of 

the incline, from which point they are taken by the rope.

The village of Cambria is lighted by electricity, and the mines have 

an electric signal system. Tha power is produced by 3 dynamos, as 

follows: One Edison 60 kilowatts of 125 volts; one Standard dynamo 

of 110 volts, which furnishes the power for a telephone and signal 

system and electric lights in the shops and houses; and 1 Milwaukee of 12£ kilowatts, 42 amperes, and 300 volts, which runs the 

telpher.

Ventilation. The mines are free from gas or fire damp, and the 

need of a system of ventilation is mainly to remove the vitiated air. 

This is done by exhaust fans located at the main entrances. Fans 

20 feet in diameter equip each of the mines except the Antelope No. 

4, which has an 18-foot fan, and the Jumbo mine, which has a 25-foot 

fan.

Tipple. The coal from all of the mines is brought to a common 

tipple in Coal Canyon. (See PL V, A) The mine cars are dumped 

by Mitchell tipples, and all of the coal is crushed and screened by 

plate and revolving screens. The slack, or that portion of the coal 

which goes through a -^-inch mesh, is carried by1 belt conveyer to 

storage bins and sold to steam plants and used under the boilers at 

the power plant. All other coal, or 85 per cent of the output, is 

shipped and used almost exclusively by the Chicago, Burlington & 

Quincy Railroad on its locomotives. The coal is loaded into open 

railroad cars on three tracks and into box cars, with box-car loaders, 

on two others, there being five loading tracks in constant use. One 

of these loaders is of the Christy type and the other is a gravity loader 

used when there are doors or windows in the end of the car. Approximately one-half of all the coal shipped from Cambria is sent out in 

box cars,

OUTPUT.

The output of coal from the mines at Cambria began with 2,985 

short tons in 1889 and increased to 542,649 tons in 1899. Since the 

latter date the production has gradually decreased to something over 

300,000 tons in 1908. The total production of the mines up to 

December 31, 1908, amounted to over 7,500,000 tons.
U. S. GEOLOGICAL SURVEY BULLETIN 499 PLATE VI

OPENING ON COAL AT MOUNT ZION RANCH, NEAR CAMBRIA, WYO.
COAL NEAR BLACK HILLS, WYOMING, S. DAK. 43 

MOUNT ZION.

Southwest from Cambria the coal bed outcrops in the ravine at the 

Mount Zion ranch, in sec. 11, T. 45 N., R. 62 W. (See PL VI.)

Section of coal bed at Mount Zion ranch.

Ft. in. 

Sandstone, white, massive................................ 12

Coal, bituminous.................................... 2-6

Sandstone, white, massive................................ 3-4

Coal, bituminous.................................... 3 4

Sandstone, gray, hard................................ 6-20

Coal, bituminous, ashy................................ 2

Sandstone, gray, massive................................. 50

The top bench is bright coal that has a splintery fracture, breaking 

in long, thin chips. The middle bench is solid, clean, bright coal, 

which works with a smooth, vertical face, but varies in thickness on 

account of sandstone partings. At the base of the bottom bench, 

which is a somewhat flaky coal and is apparently high in ash, a 

peculiar band is composed of a mass of irregularly disposed carbonized fibers resembling pine needles.

The coal shown in the section given above is exposed in a 50-foot 

drift in the south wall of the ravine. A 30-foot drift in the opposite 

bank, driven on the middle bench, shows 40 to 42 inches of clean 

coal. South and west of this outcrop the coal bed is carried rapidly 

to a considerable depth by a sharp increase in the dip.

LITTLE OIL CREEK.

From the mouth of Camp Canyon to Newcastle very little coal 

has been found. In the first draw on the west below the mouth of 

Grant Canyon a 100-foot drift by the roadside shows a thin coal bed 

between a massive white sandstone roof and floor.

Section of coal bed below Grant Canyon.

Ft. in. 

Shale, brown, with coal streaks................................. 5

Coal and shale, drab and brown............................. 2 6

Coal, bituminous.......................................... 2-4

Shale, carbonaceous, and coal streaks........................ 5-7

Clay and iron and iron nodules............................. 2

Coal, bituminous.......................................... 9

Sandstone floor.

This bed has a total thickness of about 20 inches and is believed 

to be the one mined at Cambria. No other coal was seen along the 

road, although the rocks are fairly well exposed.

About 1 mile north of Newcastle, where the coal horizon is carried 

below water level, two measurements of the bed were obtained, 

showing 9 inches of bone on 6 of coal and 3 inches of bone on 3 of coal.
44 COAL NEAR BLACK HILLS, WYO.-S. DAK.

These sections and the fact that hi the canyons on the east and west 

of this locality near Newcastle the coal horizon is represented by a 

small band of carbonaceous shale, indicate the nonworkable character of the Lakota coal south of Cambria.

ROBBERSROOST CANYON.

At the head of Robbersroost Canyon a prospect, said to be in the 

NW. J NE. J sec. 9, T. 45 N., R. 61 W., is driven 40 feet west, just 

below the edge of the plateau. A section of the coal bed shows 4 

inches of bituminous, flaky coal on 10 inches of ashy coal or bone 

lying between massive sandstones. The writer is informed by others 

that the bed here consists of 18 inches of splinty coal and that ashes 

in the bed show that part of the coal has burned. His own observations are as given above. In the stream 60 to 70 feet below and 

at the base of a massive sandstone ledge there is about a foot of 

brown carbonaceous shale. Both of these exposures are about 50 

yards below a rock-rimmed pool 20 feet in diameter near the head 

of the canyon. The writer is uncertain as to which of these beds is 

the one mined at Cambria, but in either case it is evident that the 

Lakota sandstone does not carry coal of workable thickness in this 

part of the township.

SALT CREEK.

On account of the heavy talus from the overlying sandstones, the 

coal horizon along the west side of Salt Creek can be seen only rarely, 

and measurements are difficult to obtain, although the outcrop is 

long. The southernmost exposure of the Lakota coal bed examined 

in this district is 3 miles southeast of Newcastle at the first crossing 

on Salt Creek. A drift in the east bank is caved, but the following 

section was measured at the entry:

Section of coal bed on Salt Creek.

Ft. in.

Sandstone, white, massive.................................... 10

Sand, with carbonaceous streaks.............................. 6

Sandstone, white, massive.................................... 2

Clay, drab and gray.......................................... 3

Shale, brown, sandy, carbonaceous............................ 2-6

Shale, brown, with coal streaks............................... 4

Coal, bituminous, shaly, ashy............................ 6

Shale, brown, weathers gray.................................. 4

Shale, brown, carbonaceous................................... 4

Clay, drab................................................... 6

Shale, carbonaceous, fissile................................... 2

This drift must have been driven with the idea that coal of workable 

thickness and quality would be found under the hill and the project 

abandoned when the hope was not realized.
COAL NEAR BLACK HILLS, WYO.-S. DAK. 45 

EDGEMONT.

About 8 miles north of Edgemont in Coal Canyon, in or near sec. 

22, T. 7 S., R. 2 E., there are several prospects on the coal in the 

Lakota sandstone. (See fig. 7.) The largest of these is a drift about 

75 feet long driven in the east bank of the canyon well toward its 

head. A second entry joins the first about 60 feet from the mouth. 

At this junction a small fault, probably due to landslipping, practically cuts out the coal. At the face of the prospect the bed shows 

signs of movement, but the coal is fresh and hard. The section 

under the massive white sandstone roof follows:

Section of coal bed in Coal Canyon.

Inches. 

Bone with coaly streaks........................................... 3

Coal, bituminous............................................ 2

Clay, black................................................. 2

Coal, bituminous............................................ 5

Bone........................................................ 2

Coal, bituminous............................................ 8

Clay, carbonaceous........................................... 2

Coal, very hard, splinty...................................... 9

33

This prospect, according to Harry Snyder, who kindly guided the 

writer to it, was opened by Fred Anthony about 1893. The poor 

character of the bed and the extreme difficulty of gaining access to 

the bottom of the canyon at this point with a wagon explain why 

the prospect has not been developed further.

On the west side of the canyon a few rods below Anthony's prospect 

a crooked drift has been driven about 300 feet in massive white sandstone, following a thin carbonaceous band. At some points the bed 

of carbonaceous shale, bone, and coal is nearly a foot thick, but the 

bone or shale predominates. Nowhere does the bed carry more than 

5 or 6 niches of bituminous coal. Between these two drifts two 

prospects show from 1 to 2 feet of carbonaceous shale with a band of 

coal up to 6 inches thick. A few rods farther down the canyon two 

or three prospects appear on the same coal horizon; one shows 3 feet 

of brown shale overlain by about 8 inches of coaly shale; another 

shows only brown shale.

A prospect opened in the head of Bennett Canyon in the whiter of 

1907-8 is reported to show about the same small amount of coal as 

in Coal Canyon.

Three miles east of Edgemont, on the south side of Cheyenne River, 

under a ledge of massive buff Dakota sandstone, a large prospect 

drift is caved full, so that access can not be had. Black shale and a 

small amount of bony coal were found on the dump. An outcrop
46 COAL NEAR BLACK HILLS, WYO.-S. DAK.

near by shows that the bed consists of a few niches of black carbonaceous shale resting on brown woody shale.

Two miles farther east hi the north part of sec. 11, T. 9. S., R. 3 E., 

and about 150 feet above Cheyenne River two drifts have been driven 

10 yards apart on a coal bed in the Lakota sandstone. There is at 

least 20 feet of massive sandstone below the coal and a few feet of 

shaly sandstone above. The drifts are caved and nothing was learned

TER COUNTY R-3E 

RIVER COUNTY £~ 

S"

x Coal outcrop 

FIGURE 7. Map showing location of coal near Edgemont, S. Dak.

about the thickness of the bed. Probably it thinned or pinched out, 

for after a road was graded and a stone-loading platform built the 

project was abandoned. Most of the coal found on the dump is bony 

or composed of a mass of carbonized fibers. One lump of bright 

bituminous coal 5 inches thick was seen.

On the north side of Cheyenne River, in the N. * sec. 13, T. 9 S., 

R. 3 E., two measurements of the Lakota coal were obtained about
EDGEMONT. 47

60 feet above the river. The first of these is a natural exposure and 

the second is at the entrance of a small prospect drift about 50 feet 

away, which is nearly closed by caving.

Sections of coal bed 6 miles east of Edgemont.

	Ft. in.

Sandstone, gray, massive......... 20

Shale, carbonaceous............. 10

Sandstone, gray, massive......... 5

Cannel or shaly bone............. 10

Coal, bituminous............ 8

Sandstone, gray, massive......... 1 3

Shale, brown................... 1 8

Coal, bituminous............ 5

Shale, brown, sandy............ 1 2

Sandstone, gray, massive......... 25

Sandstone, gray, massive.. 

Shale, carbonaceous......

Sandstone, carbonaceous. 

Bone and bony coal..

Coal, bituminous.....

Coal, bony..........

Sandstone, gray, massive.

Ft.

20

in.

2

2

1

11

Neither the quantity nor quality of the coal in the prospect warrants further development.

The thickest bed of coal known in the vicinity of Edgemont is in 

the southernmost bend of Cheyenne River 7 miles east of town. 

Here in the NW. i NE. | sec. 24, T. 9 N., R. 3 E., in the sandstone

FIGURE 8. Diagrammatic section of coal bed exposed in bank of Cheyenne River, east of Edgemont,

S. Dak.

bluff of the north river bank and but a few feet above water, two 

drifts have been driven about 30 feet apart. The main one is 10 feet 

wide and runs back under the massive sandstone roof at least 100 

feet. The bed exposed in this drift is from 44 to 54 inches of splint 

coal, like the splint in the Cambria mines and like the lower part of the 

bed at Aladdin. The middle of the bed shows a few inches of bright 

bituminous coal. The second drift shows 44 inches of splint coal, 

with two or three 1-inch seams of bright bituminous coal near the 

top. Within about 150 feet to the east the coal pinches down to a 

streak not over 2 inches thick, and in the opposite direction in about 

the same distance the coal disappears, and the position of the bed is 

marked by a few inches of coaly shale. Figure 8 shows the occurrence 

of this small pocket of coal as exposed in the river bluff.
48 COAL NEAR BLACK HILLS, WYO.-S. DAK. 

EAST SIDE OF BLACK HILLS.

The writer has no personal knowledge of any coal on the east side 

of the Black Hills. The only reference found is the following brief 

statement by J. E. Todd: 1

At probably the same horizon (Lakota), beds of coal a few inches thick have been 

discovered near Rapid City, Whitewood, and southwest of Minnekahta. The only 

chance of finding workable beds in such localities is the possible occurrence of' 'pockets' ' of very limited extent. Such occurrence is extremely improbable.

CHARACTER OF THE COAL. 

PHYSICAL PROPERTIES.

The United States Geological Survey recognizes six grades of coal 

anthracite, semianthracite, semibituminous, bituminous, subbituminous, lignite. Chemical analysis alone is not sufficient to separate all 

these grades because every variation in composition occurs, from 

lignite, which is high in volatile matter, to anthracite, which is high 

in fixed carbon, and no sharp distinction between the different grades 

is possible. Physical character, as well as chemical, must be used to 

distinguish the grades. The effects of weathering furnish an important criterion for separating bituminous coal from subbituminous 

and lignite. Bituminous coal has a well-developed joint system, 

which is recognizable even on small fragments, and it does not disintegrate readily. Subbituminous coal and lignite, however, on exposure 

to weather rapidly lose, moisture, crack or check with irregular 

fracture, and quickly fall to pieces. High-grade lignite and low-grade 

bituminous coal range between 9,500 to 12,000 British thermal units 

in unweathered air-dried samples.

Practically all of the coal in the Black Hills has more or less pronounced prismatic cleavage, has a calorific value on air-dried sample 

above 10,000 British thermal units, does not check on exposure to 

the weather, and so must be classed as bituminous. The calorific 

value of these coals, however, is low on account of the high percentage 

of ash which some of them contain. (Calculated as pure coal free of 

ash and moisture, the British thermal units in all are above 13,000.) 

The coal from certain benches at Cambria and at Holwell's shows 

more than 12,000 British thermal Units in air-dried samples, and is 

therefore high-grade bituminous.

In spite of the fact that coal hi the Black Hills region occurs only 

in isolated patches of small extent, all beds, wherever found, have 

practically the same physical characteristics. Where the coal bed 

has a thickness of more than 2 feet it is Usually divisible into benches 

of different grades, including bituminous, cannel, splint, and "pine1 Todd, J.E., Mineral resources of South Dakota; Bull. South Dakota Geol. Survey No. 3,1902, p. 111.
U. S. GEOLOGICAL SURVEY BULLETIN 499 PLATE VII

VIEWS SHOWING PHYSICAL CHARACTERS OF DIFFERENT COALS. 

A, Splint; B, bituminous; I', "pine needle;" D, cannei.
PHYSICAL PROPERTIES. 49

needle" coal. Where thin the bed may be any one of these, and 

were thickest may contain all of them. (See PI. VII.)

Bituminous coal is characterized by well-developed prismatic 

cleavage, by banded structure, and by an ability to withstand 

weathering. The banded structure is made by layers which are 

generally much less than an inch thick and which commonly measure 

from one-eighth inch down to mere films of alternating dull and 

bright glistening coal. Bituminous coal has a velvety luster and 

pitch-black color. It is not so brilliant nor so hard as anthracite.

Cannel is a lusterless, compact, even-textured coal, which has 

conchoidal fracture, breaks in blocks, does not disintegrate readily on 

exposure, ignites quickly, and burns without melting. Its color is 

velvety to dull black. It does not smut the hands. Cannel probably is formed from microscopic structureless algae, and owes its 

difference from ordinary bituminous coal to its different origin.

Splint is used in this report to describe coal that is very hard, has 

dull luster, ignites with difficulty because of its impurity, and makes 

a large amount of ash. It resembles bony coal in appearance, but 

differs from bone in that it will burn. It may be homogeneous or 

contain laminae of bright bituminous coal. Splint is inclined to break 

hi long thin slabs. It is supposed to be composed of finely comminuted decomposed vegetable matter containing a considerable percentage of silt.

"Pine-needle" coai, which is found at most of the principal openings, forms no great part of the bed, but is worthy of mention because 

of its peculiarity. It consists of a mass of carbonized fibers resembling pine needles embedded in bony coal and containing more or less 

pyrite. The fibers are commonly oval and rarely round in cross 

section, from 1 to 3 or 4 inches long, and very elastic. They weather 

brown on the surface but are brilliant jet black within. They 

ignite readily with a match and burn freely with a thick, black smoke. 

These fibers occur as a thin bed 1 to 2 inches thick or may be scattered more or less abundantly in splint coal. The extreme variety 

of this coal is composed almost entirely of fibers and when deeply 

weathered resembles loose peat.

The name "pine needle" has been used before and, as it is fairly 

descriptive, will be retained here. The coal, however, is probably 

not derived from pine needles, as these commonly have one flat side 

or are semicircular in cross section, whereas these fibers have round 

or oval cross section. Furthermore, in the process of alteration 

from vegetable matter to coal considerable reduction in volume 

takes place, and as the fibers are the size of pine needles they must 

originally have been much larger than any known leaves of the

19953° Bull. 499 12 4
50 COAL NEAR BLACK HILLS, WYO.-S. DAK.

Pinus family. This coal has been given considerable attention by 

Dr. Thiessen, of the National Museum, who has been unable to find 

any anatomical structure indicating that the vermicular bodies are 

either stem, leaf, or root. On the contrary, he reports that they 

appear to consist of solid resin, which suggests that they may have 

been the filling of large vessels in some type of stem.

COKING QUALITIES.

For 10 years or more coke was made at Cambria, Wyo. In 1891, 

24 beehive ovens were built and in 1895 this number was increased 

to 74. The ovens were operated chiefly to utilize the slack coal 

produced in mining operations. None of this slack was cleaned or 

washed before coking. Following are statistics of the production of 

coke at Cambria:

Statistics of production of coke at Cambria, Wyo., from 1891 to 1900. 1

1891.......................................

1892.......................................

1893.......................................

1894.......................................

1895.......................................

1896.......................................

1897.......................................

1898.......................................

1899.......................................

1900.......................................

Coal used 

(short 

tons).

4,470

0

5,400

8,685

10, 240

41,038

54,976

35,384

32,100

32,460

Coke produced 

(short 

tons).

2,682

0

2,916

4,352

4,895

19,542

24,007

18,350

15,630

14,501

Total value 

of coke at 

ovens.

$8,046

0

10,206

15,232

17, 133

58,626

72,021

64,225

38, 510

43,503

Value of 

coke at 

ovens per 

ton.

33.00

0

3.50

3.50

3.50

3.00

3.00

3.50

2.46

3.00

Yield Of 

coal in 

coke.

Per cent. 

60

0

54

50

47 A

47.6

43 7

<i1 Q

d8 7

44 7

» Mineral Resources U. S. for 1900, U. S. Geol. Survey, 1901, p. 535.

The coke ovens at Cambria are located on the valley bottom about 

one-fourth mile below the tipple and were charged with slack coal 

brought from the tipple by narrow gauge tram to the top of the 

ovens. Three-ton charges were used for 48-hour firings and 5-ton 

charges for 72-hour firings. All coke produced was sold to smelters 

in the northern Black Hills; soon after the smelters closed the production of coke at Cambria was stopped and the ovens have been 

idle since 1903.

The coal produces a hard, compact coke, bright and metallic in 

color, and having high resistance to crushing load. It is suited for 

blast-furnace fuel, its only drawback being its high percentage of 

ash. For smelting precious metal it is especially desirable if, as 

reported (p. 63), it contains appreciable percentages of gold and 

silver.

The coking quality of coal can be determined with a fair degree 

of certainty by a simple physical test, called, from its discoverer,
COKING QUALITIES. 51

the Pishel test.1 On grinding finely in an agate mortar coking coal 

will adhere strongly to the mortar and pestle; noncoking coal will 

not adhere. This test, applied to samples from the Cambria bed, 

shows that the bright bituminous coal has good coking quality but 

that the splint and cannel have not. Further testing shows that 

the bright jet-black bands of bituminous coal one-eighth to onehalf inch thick found in the noncoking bituminous and splint coal 

adhere strongly to the mortar and have superior coking qualities. 

From the fact that slack from the Cambria mines makes good coke, 

except that it is high in ash, and from the fact that tests show the 

coking qualities of the bright bituminous coal to be superior to those 

of the other grades in the same bed, it is assumed that a better 

grade of coke could be produced by sorting run-of-mine coal and 

selecting that best for coking. Omitting the cannel and splint 

would certainly lower the percentage of ash.

An average of eight tests for ash in this coke is reported by the 

owners as giving 22.40 per cent. Probably the difference in specific 

gravity between the pure coal and the splint or cannel is not sufiicient 

for thorough separation by washing or dry concentration. The price 

of coke would not warrant the expense of hand picking.

Agate-mortar tests of the coal at Hoi well's on Skull Creek show 

that the benches of bright bituminous coal probably will coke well, 

but that the splint and cannel alone would coke poorly if at all. 

By the same test it is concluded that the upper half of the main 

bed at Aladdin is coking coal, but that the lower half is not. An 

actual coking test of Aladdin run-of-mine coal finely crushed and 

fired for 27 hours in a coke oven at the St. Louis fuel-testing plant 

produced no coke.2 This result probably was due to the noncoking 

ashy coal which constitutes the lower half of- the bed and consequently formed about 50 per cent of the run-of-mine shipment. If 

the bright coal only should be tested in an oven, the writer believes 

a good grade of coke would be produced. For best results the coal 

should be finely crushed before delivery to the ovens.

CHEMICAL PROPERTIES.

SELECTION OP SAMPLES.

During the operation of the Government fuel-testing plant at St. 

Louis, Mo., a car of run-of-mine coal was shipped from Aladdin under 

the direction of M. R. Campbell and two mine samples for chemical 

analysis were taken by him at working faces in the mine. Frank W.

i Practical test for coking coal: Econ. Geology, vol. 3, No. 4, June-July, 1908, pp. 265-275. 

»Holmes, J. A., Preliminary report on the operations of the fuel-testing plant of the .United States Geological Survey at St. Louis, Mo., 1905: Bull. U. S. Geol. Survey, No. 290,1906, p. 229.
52 COAL NEAR BLACK HILLS, WYO.-S. DAK.

DeWolf procured the shipment of a car of the commercial grade of 

engine coal produced at Cambria, which is a run-of-mine crushed and 

screened over a J-inch screen, and also obtained two mine samples 

by making cuts from roof to floor of the bed.

For the purpose of comparison and classification, the writer took 

separate samples at Aladdin, Holwell's, and Cambria of the different 

benches of the beds there developed.

All of these samples were collected in a uniform manner in accordance with the following instructions for coal sampling:

Select a clean face of coal and across the bed from top to bottom cut a channel of 

sufficient depth to obtain 5 pounds of coal for each foot of bed, discard all partings 

more than one-fourth inch thick and lenses or concretions more than 2 inches in diameter and one-half inch in thickness. The material thus obtained should be caught upon 

canvas or oilcloth to exclude dirt and excess moisture.

The sample thus obtained should be pulverized, in the mine if possible, until none 

of the fragments exceed one-half inch in diameter. The coal should then be mixed 

thoroughly and divided into four quarters, the two opposite discarded, and the remaining two mixed and quartered again. This process should be continued until the final 

sample is reduced to about 1 quart, which is to be placed in a can, sealed air-tight, 

and sent to the laboratory for analysis.

This method, used by all members of the Survey in such work, 

assures uniform and fairly representative samples, and the sealing of 

the cans insures the coal reaching the laboratory practically unchanged 

as regards its moisture content. 1

COMPOSITION.

The few analyses of Black Hills coal that have been made by the 

survey are given in the table on page 53. Four analyses of a single 

sample are given. The analysis of air-dried coal is more nearly representative of the coal as it reaches the consumer, as a considerable 

percentage of the moisture is lost after mining.

1 For a detailed description of the methods employed in the chemical analysis of coals, see: Parker, 

E. W., Holmes, J. A., and Campbell, M. R., committee in charge, Report on the operations of the coaltesting plant of the United States Geological; Survey at the Louisiana Purchase Exposition, St. Louis, 

Mo.. 1904: Prof. Paper U. S. Geol. Survey No. 48, pt. 1,1906.
Analyses of coal samples from the Black Hills coalfield

[F. M. Stanton and A. C. Fieldner, chemists in charg

Laboratory 

No.

1376 

1377 

1571 

6793 

6790 

6792 

6745

Location.

Quarter.

SE.... 

NW...

SE....

SE....

Sec.

19 

29

20

19 

19 

19 

31

T. N.

46 

46

46

46 

46 

46 

4S

R. W.

61 

61

61

61 

61 

61 

62

Airdrying 

loss.

4.7 

 3.8 

6.9 

7.2 

4.6 

11.8 

10.5

Form of analysis.

Air dried. ............

Air dried.............

Proximate.

Moisture.

8.6 

4.0

9.2 

5.6

9.5 

2.7

9.8 

2.8

6.6 

2.0

14.1 

2.5

14.4 

4.3

Volatile 

matter.

37.1 

39.0 

40.6 

53.4

36.1 

37.5 

39.7 

51.7

35.0 

37.6 

38.7 

50.1

41.0 

44.2 

45.5 

50.1

35.3 

37.0 

37.8 

51.4

34.1 

38.7 

39.7 

48.2

26.0 

29.0 

30.3 

40.7

Fixed 

carbon.

32.4 

34.0 

35.4 

46.6

33.7 

35.1 

37.2 

48.3

34.8 

37.4 

38.4 

49.9

40.9 

44.0 

45.3 

49.9

33.3 

35.0 

35.7 

48.6

36.6 

41.6 

42.6 

51.8

37.8 

42.3 

44.2 

59.3

Ash.

21.9 

23.0 

24.0

21 

21 

23

.0 

8 

1

20.72 

22.26 

22.88

8.31 

8.96 

9.22

24.78 

25.97 

26.52

15 

17 

17

19 

22 

67

21.8 

24.4 

25.5

Sulphur.

4.94 

5.18 

5.40 

7.11

4.33 

4.50 

4.77 

6.20

3.91 

4.17 

4.29 

5.56

4.44 

4.78 

4.92 

5.42

4.38 

4.59 

4.69 

6.38

4.42 

5.01 

5.14 

6.24

3.10 

3.46 

3.62 

4.86
Analyses of coal samples from the Black Hills coalfield, Wyo

Laboratory 

No.

6747 

6743 

6744 

6746 

1976 

1977 

2278

Location.

Quarter.

SE.... 

SE.... 

SE.... 

SE....

Sec.

31 

31 

31 

31 

27 

27 

27

T. N.

48 

48 

48 

48 

54 

54 

54

R. W.

62 

62 

62 

62 

. 61 

61 

61

Airdrying 

loss.

15.3 

10.7 

14.1 

12.6 

11.8 

2.9 

2.9

Form o/ analysis.

Air dried.............

Air dried.............

Proximate.

Moisture.

20.4 

6.0

14.0 

3.6

18.1 

4.7

16.8 

4.8

17.7 

6.7

18.4 

7.3

15.1 

12.6

Volatile 

mat- 

' ter.

. 26.7 

31.6 

33.6 

43.5

23.8 

26.7 

27.7 

38.5

20.8 

24.2 

25.4 

41.5

38.7 

44.3

df{ P»

49.5

37.6 

42.7 

45.8 

53.2

36.5 

41.5 

44.8 

51.1

34.4 

35.4 

40.5 

50.4

Fixed 

carbon.

34.8 

41.1 

43.7 

56.5

38.0 

42.6 

44.2 

61.5

29.3 

34.1 

35.7 

58.5

39.5 

45.2 

47. 5

50.5

33.1 

37.5 

40.2 

46.8

35.0 

39.7 

42.8 

48.9

33.8 

34.8 

39.8 

49.6

Ash.

18 

21 

22

1 

3

7

24.16 

27.06 

28.08

31.8 

37.0 

38.9

4. 

5. 

5

96 

68 

96

11.6 

13.1 

14.0

10.1 

11.5 

12.4

16.70 

17.20 

19.67

Sulphur.

2.11 

2.36 

2.45 

3.41

1.28 

1.49 

1.56 

2.55

3.57 

4.09 

4.29 

4.56

7.03 

7.97 

8.55 

9.94

6.73 

7.64 

8.25 

9.41

6.66 

6.86 

7.85 

9.77
9320

9321

10410 NE...

27

29

54

54

49

61

61

63

13.1

9 7

7.7

17.8

5.4

14.0

4.8

11.6

4.2

37.6

43.2

45.7

48.7"

<»36.8

40.7

42.8

49.0

33.1

35.9

37.4

49.3

39.5

45.5

48.1

51.3

38.3

42.4

44.5

51.0

34.0

36.8

38.5

50.7

5.11

5.88

6.21

10.93

12.10

12.71

21.30

23.08

24.09

5.60

6.45

6.81

7.26

4.97

5.51

5.78

6.62

2.64

2.86

2 99

3.94

a By modified method.

1376. Mine sample, Cambria, working face, whole bed, room 6 off third north west entry, 

"Antelope No. 3 and room 7 northwest, Antelope No. 1, mixed. F. W. De Wolf, 

1905.

1377. Mine sample, Cambria, working face, whole bed, room 9 off the eighth northwest

entry in Jumbo mine. F. W. De Wolf, 1905. 

1571. Car sample, Cambria, used for gas-producer test. 

6793. Hand-selected sample, best bituminous, Cambria, fresh mined, taken from cars as

delivered at tipple, Antelope mines. R. W. Stone, November 4,1908. 

6790. Hand-selected sample, splint, Cambria, fresh mined, taken from cars as delivered

at tipple, Antelope mines. R. W. Stone, November 4,1908. 

6792. Bin sample of slack from crusher, Cambria, used under boilers at mine. R. W.

Stone, November 4,1908. 

6745. Mine sample, Holwell's, Skull Creek, face of 95-foot drift, not worked recently,

whole bed. C. T. Lupton, October 25,1908. 

6747. Mine sample, Holwell's, Skull Creek, face of 55-foot drift, not worked recently,

whole bed. C. T. Lupton, October 25,1908. 

6743. Mine sample, Holwell's, Skull Creek, face of 55-foot drift, not worked recently;

cannel, middle bench. C. T. Lupton, October 25,1908.

6744. Mine sample, Ho

bench, splint or 

6746. Mine sample, Hol

bituminous, tw

1976. Mine sample, Al

works, 35 feet 

M. R. Campbell

1977. Mine sample, Ala

bed. M. R. Ca

2278. Car sample, Alad

9320. Mine sample, Ala

coal. R. W. St

9321. Mine sample, Ala

or bony coal. 

10410. Hand-selected sa

taken by Charl
56 COAL NEAR BLACK HILLS, WYO.-S. DAK.

The analyses given in the table show that moisture in air-dried 

samples of Black Hills coal ranges from 2 to 7.29 per cent. One 

exception to this is a car sample from Aladdin which showed 12 per 

cent moisture, although four mine samples from the same place, 

which should naturally have been practically the same, carried from 

4 to 7.29 per cent moisture. The writer suspects that the air-drying 

loss for No. 2278 should be 12.90 instead of 2.90. If this is the case, 

the analyses of the coal air-dried, dry, and pure should be recalculated.

The Black Hills coal is a high-volatile fuel, the average percentage 

of volatile matter nearly equaling that of fixed carbon. From the 

seventeen analyses of air-dried coal given in the table it is found 

that the usual amount of volatile matter is 37 per cent for the field, 

and of the fixed carbon 39.34. The volatile matter ranges from 

24.21 to 44.27 per cent, these two extremes being in different benches 

of the same bed at Holwell's. A considerable part of the fuel value 

of coal is contained in the volatile matter. Hydrogen exceeds carbon 

in heat value, and thereby raises the calorific value of coal above that 

of the contained carbon alone. Coals which contain a large proportion of volatile matter ignite easily and burn with long, often sooty, 

flames. Steaming with a high-volatile coal involves considerable 

waste, as unless used in a specially constructed furnace or fire box 

the combustion of the gases is likely to take place in the stack and its 

energy be lost.

Fixed carbon in these coals ranges from 34 to 45.5 per cent and 

averages 39.34 for the field. This is the principal fuel constituent 

and the most efficient of the heat-producing factors. Combustion 

takes place on the grate by chemical combination of the carbon with 

the oxygen of the air.

Ash is by no means insignificant in the Black Hills coal. The 

analyses show quantities from less than 6 per cent to more than 37 

per cent. These extremes do not represent whole beds but kinds of 

coal, the former being a bench of the best bituminous and the latter a 

splint. Cannel coal in this field carries 23 to 27 per cent ash, while 

bituminous coking coal in an under or overlying bench of the same 

bed has only 6 to 8 per cent of ash. Being an inert constituent from 

a heating standpoint, so large a percentage of ash as some of the coal 

contains is very objectionable, both because ash clogs the grate and 

hinders free combustion of the coal and also because of the cost of 

transporting. The percentage of ash in the bed at Aladdin, according 

to three analyses of air-dried coal (1976, 1977, 2278) is nearly 14 per 

cent, although the better coal in the upper half of the bed has only 

about 6 per cent ash. At Cambria the ash seems to be over 22 per 

cent. This is shown by two analyses (1376, 1377) of samples from 

the whole bed, excluding clay partings, arid by a car sample (1571). 

An analysis (6793) of the best coal from the Antelope mines, made
TESTS. 57

from a hand-selected sample from cars as delivered at the tipple, gives 

only 9 per cent ash in air-dried coal, but splint or poor coal selected 

the. same way shows 26 per cent ash. Hauling nearly a ton of ash 

for every 4 tons of coal would seem to be very near the limit of profitable transportation.

In the ultimate analyses the elements determined are sulphur, 

hydrogen, carbon, nitrogen, and oxygen. These were determined in 

more than half of the samples in the above list.

The presence of sulphur in coal is objectionable despite the fact 

that it is combustible and develops heat. Not only does it give an 

offensive odor on burning but it corrodes the metal parts of the furnace. In the manufacture of iron and steel and in other metalliferous 

processes sulphur in the coal has a detrimental effect. The percentage 

of sulphur in the Black Hills coal is about 2.79 at HolweLTs, 4.7 at 

Cambria, and 6.84 at Aladdin.

Hydrogen is in part combined with oxygen in the form of water and 

is therefore not heat producing. The remaining disposable hydrogen, 

being free to combine with oxygen on combustion, is a source of heat.

Carbon, of course, is the principal fuel element.

Nitrogen has no heat-producing power and lacks affinity for the 

other elements.

The oxygen in the coal is so combined with other elements as to 

be nonproductive of heat, most of it being in combination with hydrogen to form water.

Calorific value, as shown by calories and British thermal units, 

furnishes the most satisfactory means of comparison that can be derived from laboratory tests. Knowing the heat value, the ash content, and the physical character of a coal, a general estimate can be 

made of the adaptability of a coal for different purposes. Statements of the meaning of the values and of the method of obtaining 

them have been published elsewhere 1 and need not be repeated here. 

So far as shown by the analyses, for all of which the heat values were 

not determined, the bright coal at Cambria and at Holwell's is the 

best or highest in calorific value and the cannel coal is the lowest.

TESTS.

AT THE U. S. GEOLOGICAL SURVEY FUEL-TESTING PLANT.

During the Louisiana Purchase Exposition and in subsequent 

months in 1904-5 the fuel-testing plant of the United States Geological Survey at St. Louis, Mo., conducted a series of tests on a considerable number of coals from numerous coal fields in the United States. 

Among these coals were three from the State of Wyoming: No. 1, 

Monarch coal from Sheridan; No. 2, Lakota coal from Cambria; and

1 Prof. Paper II. S. Geol. Survey No. 48, pt. 1, pp. 179-184. Voorhees, S. S., Methods of testing coal: Proc. 

Am. Soc. Testing Mat., vol. 7,1907, pp. 560-571. Bull. U. S. Geol. Survey No. 415,1910, pp. 241-243.
58 COAL NEAR BLACK HILLS, WYO.-S. DAK.

No. 3, Lakota coal from Aladdin. The results of these tests were 

published in Professional Paper 48 and Bulletins 261 and 290 of the 

United States Geological Survey. The main points ascertained are 

summarized and tabulated in the following pages. For further details reference should be made to the reports mentioned above.

Steaming tests.

Factors in test.

Heating value of coal, B. t. u. per

pound dry coal. ...................

Force of draft:

" Under stack damper . inch water. .

Above fire.............. ..do. . ..

Furnace temperature. ........... °F. .

Dry coal per square foot of grate surface per hour..... . ....... .pounds. .

Equivalent water evaporated per

square foot of water-heating surface per hour.... . ........ .pounds. .

Percentage of rated horsepower of

boiler developed .......... pounds. . Water apparently evaporated per 

pound of coal as fired ..... pounds. . Water evaporated from and at 212° F.:

Perpoundofcoalasfired.pounds. . 

Per pound of dry coal... . . .do. ...

Per pound of combustible, .do. ...

Efficiency of boiler, including grate, 

per cent. ...........................

Coal as fired:

Per indicated horsepower hour,

pounds ........................

Per electrical horsepower hour,

pounds ........................

Dry coal:

Per indicated horsepower hour,

pounds ........................

Per electrical horsepower hour,

pounds ........................

Sheridan.

63

11,947

0.62

.23

22.69

3.17

88.8

4.58

5.47 

7.00

7.66

54.89

4.04

4.99

Cambria.

61

10,897

0.49

.14

26.51

3.13

87.76

4.41

5.26 

5.92

8.26.

52.46

4.77

5.9

196

10,888

0.59

.19

1,950

22.61

2.83

79.3

4.83

5.66 

6.27

8.54

55.61

5.00

6.17

4.51

5.57

210

11,261

0.68

.20

2,067

25.66

3.15

88.3

5.30

6.19 

6.84

9.01

58.66

4.57

5.64

4.13

5.10

213

10,751-

0.63

o.08

2,228

32.58

3.56

99.86

4.72

5.56 

6.10

8.30

54.79

5.09

6.28

4.64

5.72

Aladdin.

211

10,519

0.63

.28

1,917

18.96

2.39

67.0

5.12

5.98 

7.04

9.17

64.63

4.73

5.84

4.02

4.96

212 

10,517

0.45

&. 01

2,142

26.07

3.15

88.2

4.95

5.81 

6.73

8.59

61.80

4.87

6.01

4.20

5,19

223

12,641

0.59

.23

20.0

2.89

81.0

5.54

6.53 

8.07

9.05

61.65

4.33

5.35

3.50

4.33

a Forced draft. 6 Natural and forced draft.

Analyses of coal used for steaming tests.

Constituents.

PROXIMATE.

Fixed carbon. . ......................

Ash..................................

ULTIMATE.

Ash..................................

Sheridan.

63

21.81 

40.56 

31.61 

6.02

100.00 

.63

69.46 

4.90 

15.83 

1.30 

.81 

7.70

Cambria.

61

11.10 

35.55 

34.58 

18.77

100.00 

3.87

58.16 

4.47 

11.07 

.84 

4.35 

21.11

196

9 64 

34.75

34.68 

20.93

100.00 

4.32

58.01 

4.23 

8.93 

.89 

4.78 

23.16

210

9.55 

35.75 

35.73 

18.97

100.00 

3.95

60.09 

4.39 

9.25 

.92 

4.37 

20.98

213

8.94 

35.90 

33.70 

21.46

100.00 

5.03

57.08 

4.16 

8.80 

.87 

5.52 

23.57

Aladdin.

211

15.12 

34.36 

33.82 

16.70

100.00 

6.66

56.73 

4.15 

10.77 

.83 

7.85 

19.67

212

13.60 

36.12 

34.07 

16.21

100.00 

7.90

56.44 

4.12 

10.72 

.82 

. 9.14 

18.76

223

19.08 

36.58 

37.56 

6.78

100.00 

4.26

67.60 

4.94 

12.83 

.99 

5.26 

8.38

a Figured from car sample.
TESTS. 

Coal consumed in producer-gas tests in pounds per hour.

In producer. 

Per electrical horsepower:

Per brake horsepower:

In producer plant. 

Per electrical horsepower:

Developed at switchboard ................

Per brake horsepower:

Developed at engine. . .....................

Cambria (No. 16).

Coal 

as 

fired.

2.18 

2.00

1.86 

1.70

2.49 

2 28

2.11 

1.94

Dry 

coal.

1.98 

1.82

1.68 

1.54

2.25 

2.07

1.92 

1.76

Combustible.

1.52 

1.40

1.30 

1.19

1.74 

1.60

1.48 

1.36

201.2 

151 

12,100

Cambria (No. 62).

Coal

as 

fired.

2.28 

2.16

1.93 

1.83

2.40 

2.28

2.05 

1.94

Dry 

coal.

2.08 

1.97

1.77 

1.68

2.20 

2.09

1.87 

1.77

Combustible.

1.59 

1.50

1.35 

1.28

1.68 

1.59

1.43 

1.35

192.9 

146.6 

20,400

Aladdin (No. 69).

Coal 

as 

fired.

2.05 

1.92

1.74 

1.63

2.19 

2.04

1.86 

1.74

Dry 

coal.

1.78 

1.67

1.52 

1.42

1.90 

1.78

1.62 

1.51

Combustible.

1.47 

1.37

1.25 

1.17

1.57 

1.46

1.33 

1.24

193.1 

160.9 

17,400

Analyses of coal used in producer-gas test and of gas produced.

Constituents.

Coal.

Ash................................................:...........................

Sulphur. .......................................................................

Gas by volume.

Methane.. . .....................................................................

Cambria.

16

9.44 

35.02 

34.82 

20.72 

3.91

10.21

.59

15.46 

10.79 

5.52 

57.43

62

8.63 

36. 81 

32.83 

21.73 

4.47

10.8

18.2 

10.7 

3.3 

57.0

Aladdin.

69

13.02 

37.56 

34.05 

15.37 

7.36

11.1

19.8 

13.3 

3.5 

52.3

Washing test.

[Test 129, Wyoming No. 3 (Aladdin). Size as shipped, run of mine; size as used, crashed to 2 inches

Jig used, Stewart modified.] 

Raw coal........................................... pounds.. 24,120

Washed coal.......................'................... .do.... 20,060

Refuse ..........................................do.... 4,060

Analyses.

Test 129.

Constituents.

Volatile matter. ....................................................................

Ash. .................................... ....................................

Sulphur.. . ....................................................................... .

Raw 

coal.

15.12

34.36

33.82

16.70

6.66

Washed 

coal.

19.16

6.52

4.16
60 GOAL NEAR BLACK HILLS, WYO.-S. DAK.

Coking test.

[Test 52, Wyoming No. 3 (Aladdin), washed. Size as shipped, run of mine; size as used, finely crushed.

Duration of test, 27 hours.J

No coke produced.

The following statements concerning the results of these tests were 

published in the report of the coal-testing plant: l

The results obtained on the coal from Cambria are lower than those from the Sheridan lignite, but this is due in large measure to the heavy percentage of ash that ia 

carried by the Cambria coal. The recalculated analysis, in which the ash is thrown 

out, shows that the Cambria coal is superior to the other.

Some briquetting tests were made on these samples, but they gave no promise of 

success in a commercial way.

The best results were obtained by using this coal (Cambria) in the producer-gas 

plant. The results show that with the (Wyoming No. 2) Cambria coal it required 

2.07 pounds of dry coal to produce one electrical horsepower hour, whereas when used 

in the steam plant it required 5.9 pounds of dry coal to produce the same result. It 

is probable that equally good or better results could have been obtained with Wyoming No. 1 (Sheridan coal at Monarch), since in general the quality of the gas improves 

as one descends in the scale of quality of coal, the best results being obtained from 

brown lignite.

Of the results when Cambria coal was used in the gas-producer 

engine, the following was said: 2

Wyoming No. 2 is a bituminous coal. It burned without any clinkering, leaving 

a large amount of white ash similar to that obtained from wood. The gas was not uniform in quality, on account of the difficulty experienced in keeping the bed in good " 

condition, which made more or less trouble in securing the proper mixture of air and 

gas. There was also some slight trouble with the ignition setting. Sixty gallons of 

yellow tar were taken from the gas.

MISCELLANEOUS TESTS.

The results of boiler tests of the Cambria coal made by the Cambria Fuel Co., at Cambria, Wyo., and by the Lincoln Traction Co., 

Lincoln, Nebr., have been furnished by the respective companies and 

are given below for comparison with the results of the Government

tests.

1 Parker, E. W., Holmes, J. A., and Campbell, M. R., committee in charge, Report of the operations of 

the coal-testing plant of the United States Geological Survey at the Louisiana Purchase Exposition, 

St. Louis, Mo., 1904: Prof. Paper, U. S. Oeol. Survey No. 48, 1906, pt. 1, p. 141.

2 Idem, pt. 3, p. 1314.
TESTS. 61

Results of evaporative tests oj Cambria coal. 

[Made by the Cambria Fuel Co., Cambria, Wyo.)

1. Date of trial ...................... .1907 . .

3. Weight of coal fired ........... .pounds. . 

4. Total weight water fed to boiler. . .do. ... 

5. Equivalent water evaporated from and 

at 212° F .................. .pounds. .

7. Water evaporated per hour from and at 

212° F ...................... .pounds . . 

8. Equivalent evaporation from and at 

212" F. per square foot of water-heating 

surface. ..................... .pounds . . 

9. Steam pressure (gauge) .... .pounds per

12. Pressure of blast under furnace, inches

14. Builder's rated horsepower. .............

15. Per cent of builder's horsepower devel10. Water apparently evaporated under actual conditions per pound of coal as 

fired ........................ .pounds . . 

17. Equivalent evaporation from and at

1,786.5......................

8............................

11,250.......................

46,357.......................

55,211.......................

1,406........................

6,901.4.......................

3.86......................... 

99.7.........................

66.75.......................

1.191........................

3 ...........................

200. 4 .......................

150.........................

4.12......................... 

4.91.........................

1,609. 5.

8.

7,125. 

36,560.

43,506.

890.

5,438.3.

3.37. 

95.5.

66.

1.19.

3.

157.6.

135.

116.

5.13. 

6.10.

NOTE. (1) Capacity obtained in excess of guarantee, 16 per cent; (2) economy obtained, stoker firing 

over hand firing, in excess of guarantee, 22.4 per cent. Test made by Gordon L. Huchins, M. E.

Boiler tests made by Lincoln Traction Co., Lincoln, Nebr., on Cambria and Wcir-Pittsburg

coals.

Date of trial. . ................................ .1904. .

Duration of trial. . .......................... .hours. .

Weight of coal as fired.. ................... .pounds. . 

Total weight of water fed to boiler. ............ do ....

Equivalent water evaporated into steam from and at 

212° F .................................. .pounds. .

Water apparently evaporated under actual condiEquivatent evaporation from and at 212s' F. per 

pound of coal as fired. ................... .pounds. .

Cambria, Wyo., coal.

1

Nov. 23 

10 

No. 1-3-4 

37,845 

195, 500 

1. 1066

216,340 

140 

155

5.16 

5.72

$2.05 

SO. 179

2

Nov. 25 

10 

No. 1-3-4 

48,000 

242,029 

1. 1191

270,854 

140 

143

5.04

5.64 

8,837 

18 

$2.05 

$0. 182

3

Nov. 30 

10 

No. 1-3-4 

45,850 

245,848 

1.1128

273, 579 

140 

149

5.36

5.96 

9,120 

20 

$2.05 

$0. 172

Weir-Pittsburg, 

Kans., coal.

1

Dec. 3 

10 

No. 1-3-4 

41,400 

273,390 

1.126

307,837 

135 

135

6.6

7.43 

5,514 

13.3 

$2.35 

80.158

2

Dec. 5 

10 

No. 1-2-4 

42,100 

265, 200 

1.1285

299,278 

140 

133

6.3

7.1

7,800 

18.5 

$2.35 

$0. 165
62 COAL NEAB BLACK HILLS, WYO.-S. DAK.

A test made at the municipal pumping station, Hastings, Nebr., to 

determine the comparative efficiency and cost of several available 

coals showed best results with Cambria coal. The results of the 

tests, as sworn to by E. J. Peare and H. W. Main to the mayor and 

council of Hastings, are given in the following table:

Tests of different coals made at municipal pumping station, Hastings, Nebr.

Date.............. ....... .....1896..

Water pumped. . ......... .gallons. . Coal consumed ............ pounds . . Water pumped per pound of 

coal. ... ................. .gallons. . 

Cost of pumping 100,000 gallons. ....

Cambria, 

Wyo., 

steam.

Aug. 13-15

53,927

970,686 

29,853

32J 

$4.15

Sheridan. 

Wyo., 

lump.

Aug. 25-27

40, 598

730,764 

25,947

284 

$5.77

Bevier, Mo., 

steam.

Aug. 28-29

33, 580

604,440 

23, 436

25J 

85.30

Rich Hill, Mo., 

mixture.

Aug. 21-Sept. 2

51, 704

930,672 

30,690

30J 

$4.70

Muchakinock, 

Iowa, 

steam.

Sept. 3-5

48,244

868, 392 

32; 922

26J 

84.99

SUMMARY OF TESTS.

The foregoing tests and analyses show somewhat conflicting results 

'concerning the value and efficiency of the Black Hills coals when 

compared with competing coals. The high percentage of ash in the 

coal mined at Cambria and Aladdin is about counterbalanced by 

the high percentage of moisture in that mined at Sheridan. When 

compared on a pure-coal basis (ash and moisture free), the Black Hills 

coal is superior, but if comparative producer-gas tests were available 

the Sheridan coal would undoubtedly be found more efficient. For 

steaming there is little preference between Black Hills and Sheridan 

coal. In the foregoing tables this is shown by a comparison of the 

number of pounds of water apparently evaporated per pound of 

coal as fired. It may be summarized thus:

Water evaporated per pound of coal fired.

Pounds. 

Sheridan coal (1 test)........................................... 4. 58

Cambria coal (average of 9 tests)................................. 4. 89

Aladdin coal (average of 3 tests)................................. 5. 20

The writer believes that the comparative value of coals competing 

with Cambria coal is fairly well expressed by T. J. Grier, superintendent of the Homestake Mining Co., Lead, S. Dak., who said, in writing 

of results obtained at the Homestake mine, which uses about 225 

tons of coal daily: "The coals weighed were Glenrock, Fetterman, 

Hanna, Cambria, Sheridan, and Monarch, and the results obtained 

did not seem to show any more difference in fuel value than would 

be made by a careful fireman as compared with one who was not so 

careful." Under these conditions where competing coals of different 

character have practically the same fuel value the factors deterniining which shall be used are constancy of supply and cost per ton 

delivered. Freight rates affect cost very materially.
COAL NEAR BLACK HILLS, WYO.-S. DAK. 63

GOLD IN CAMBRIA COAL.

An interesting feature about the Cambria coal is that it is said 

to be gold bearing. According to a verbal statement by W. E. 

Mouck, superintendent of the Cambria mines, an assay made by the 

company's chemist of ashes from the boiler house showed $10 per ton 

and of the sandstone roof of the bed $2 per ton in gold. This unexpected result led to further investigation, and soot from the furnace 

stack was assayed, with the result that it was found to contain $4 per 

ton in gold. The coal itself has shown from nothing up to $2 per ton 

in gold when the coal was selling for $1.50. In 1896, when coke made 

at Cambria was selling for $3.50 per ton, samples were taken from 31 

cars during a period of three weeks and were assayed by the company's chemist. The samples from 31 cars of coke showed an average 

of $2.46 per ton in gold and $0.28 in silver. The following results of 

these assays were kindly furnished by the Cambria Fuel Co.:

Gold and silver assays of coke made from Cambria coal.

[Values per ton.)

Date.

1896 

July 18. ................................................

18.................................................

25. ................................................

25.................................................

25.................................................

28.................................................

28.................................................

28.................................................

28.................................................

28.................................................

28.................................................

28.................................................

28.................................................

28.................................................

28.................................................

30.................................................

30.................................................

31.................................................

Aug. 3. ...............................................

3................................................

3................................................

5................................................

5................................................

5................................................

6................................................

0................................................

8. ........... .\ ..................................

8 ...............................................

8................................................

8................................................

8................................................

Sample 

from Burlington & 

Missouri 

RiverR.R. 

car No. 

3071

3871

3711

3761

3693

2835

3691

3805

3887

4013

3801

3855

3947

3871

3763

3695

1859

3761

3711

3691

3859

3887

3695

4013

3855

3835

3801

4015

3685

3813

3671

Gold.o

82.00

2.40

2.00

3.60

2.40

2.80

3.20

2.40

2.00

2.00

2.00

2.60

3.60

2.40

2.00

5.60

3.20

2.00

2.00

2.20

2.00

2.00

2.20

2.00

2.00

2.40

2.00

2.40

2.00

2.80

2.20

2.46

Silver.!*

SO. 08

.12

.08

.00

.13

.30

.40

.34

.46

.47

.47

.34

.65

.46

.4.1

.21

.16

.41

.34

.42

.37

.00

.21

.14

.43

.39

.10

.20

.16

.16

.14

.28

Total.

82.08

2.52

2.08

3.60

2.53

3.10

3.60

2.74

2.46

2.47

2.47

2.94

4.25

2.86

2.41

5.81

3.36

2.41

2.34

2.62

2.37

2.00

2.41

2.14

2.43

2.79

2.10

2.60

2.16

2.96

2.34

2.74

» Valued at $20 per ounce. 

Henry C. Beeler, chemist, Cambria, Wyo., August 8, 1896.

& Valued at $0.65 per ounce.
64 COAL NEAR BLACK HILLS, WYO.-S. DAK.

Smelters at Deadwood, S. Dak., which used the Cambria coke, must 

have profited by it, for they recovered not only the gold in their ores, 

but the gold from the coke also.

Gold was found in some of the coal from the Jumbo mine and the 

Antelope mines 1 and 2. The distribution of the gold in the mines 

was never determined. There is more gold in the splint and bony 

coal than in the best bituminous. It may be associated with pyrites, 

which occurs commonly in the splint and "pine needle" coal.

As there are no'known dikes or veins within many miles of the 

coal mine at Cambria, the gold can not be explained as derived from 

such a source. That the gold was introduced in the quiet waters 

of the swamp, either in solution or as very fine particles in suspension, 

and deposited there by precipitation or by gravity is not impossible 

nor yet readily conceivable; first, because it is presumed that the water 

discharged into the swamp was comparatively fresh meteoric water 

and would not have dissolved gold; cecond, because drainage in 

and around a large swamp is very sluggish. Under such topographic 

conditions it is hardly probable that even fine gold would reach and 

be distributed in a large swamp. The most plausible explanation 

seems to be that the sands which submerged the swamp and now 

form the roof of the coal bed were derived in part from old goldbearing alluvium. It was noted above that the sandstone roof carries 

some gold. Currents which transported the sand and the grit which 

occurs in some places a few feet above the coal certainly were strong 

enough to transport fine gold. While the sand was being deposited 

the gold may have worked down into the underlying bog and is now 

found in the coal.

PROSPECTS FOB THE FUTURE.

From the evidence it seems to the writer that the acreage of coal 

near Cambria as yet untouched is sufficient to keep the mines there 

in operation for many years at the present rate of output. It is 

possible that a body of coal large enough to warrant the opening of 

a mine may be found at the Holwell ranch, but this has not been 

proved and is seriously questioned; moreover, until a railroad is 

built down Skull Creek there is no reason for opening a mine at Hoiwell's, as there is no demand for coal in that region. At none of the 

other places between Aladdin and Edgemont where coal has been 

found did the writer see enough good coal to suggest that any of them 

would ever supply a tonnage worthy of record. It is possible that 

at some points coal may be taken for local ranch use, but that any 

of the localities besides Cambria will ever in future add to the State's 

record of coal produced and shipped is doubted.
INDEX.

Page. 

Acknowledgments to those aiding........... 7

Aladdin, coal and sandstone near, sections of. 15,21 

coal near, analyses of................. 20,54-55

character and occurrence of......... 18-21

tests of........................... 58-60,62

Lakota sandstone at, plate showing..... 18

mines and prospects near, figure showing . 19 

output of............................ 20

sections near......................... 15,16,21

Stilwell Co.'s mine at, plate showing..... 18

Analyses, of Black Hills coal, tables showing.. 53-55 

Antelope mines, sections of coal beds in...... 35-36

See also Cambria. 

Bevier coal, test of........................... 62

Bibliography of Black Hills coal resources.... 5-6

Black Hills, coal of, analyses of.............. 53-57

coal of, character and distribution of...... 17-64

chemical properties of............... 51-52

coking qualities of................ 50-51,60

occurrence of......... l.............. 17-48

physical properties of................ 48-50

production of..................... 20,42,64

sections of, plate showing............ 34

tests of.............................. 57-62

general map of.......................... 6

geology of............................... 7-17

location and topography of.............. 7

stratigraphy of.......................... 8-17

structure of.............................. 7-8

Boiler tests, of Cambria and Weir-Pittsburgh

coals, results of.................. 61

Cambria, coal from, analyses of.............. 37,53

coal from, character and occurrence of.... 34-37

tests of........................... 58-59,61

coke production of....................... 50-51

development at.......................... 34

Lakota sandstone near, plate showing.... 10

mine and civic equipment of............. 38-42

mine workings near, figure showing..... 33

output of mines of....................... 42

population and buildings of............. 38-39

railroad facilities of...................... 39

stratlgraphic relations near.............. 10-12

view of, plate showing................... 38

water supply of.......................... 39

Cambria Fuel Co., mininj; equipment of...... 39-42

tipple of, plate showing.................. 38

Camp Canyon, Lakota sandstone in, plate

showing......................... 18

Cheyenne River, outcrops of coal along...... 45-47

section of coal near, figure showing...... 47

Coal, analyses of............................. 53-57

beds of, character, distribution, development and sections of.......... 17-48

sections of, plate showing........... 34

19953° Bull. 499 12 5

Page.

Coal, character of............................ 48-64

chemical properties of................... 51-52

coking qualities of.................... 50-51,60

gold in, occurrence of.................... 63-64

physical properties of.................... 48-50

plate illustrating.................... 48

producer-gas tests of.................... 59

production of......................... 20,42,64

steaming tests of......................... 58

tests of.................................. 58-62

washing tests of......................... 59

Coke, production of.......................... 50-51

Coking test, on Black Hills coal, results of..... 60

Dakota sandstone, character and thickness of. 16-17 

exposures of, plates showing............. 10,16

sections of............................... 10-13

Dry Creek, section at prospect near.......... 27

East Plum Creek, sections of coal beds on.... 31

Edgemont, occurrence of coal near........... 45-47

occurrence of coal near, figure showing.... 46

section of coal near, figure showing........ 47

sections near......................... 15,45,47

Evaporative tests of Cambria coal, results of.. 61 

Fuson shale, character and thickness of....... 15-16

sections of............................... 16,27

Gold, in Cambria coal, occurrence and assays

of............................... 63-64

Graneros shale, character and occurrence of... 17 

Grant Canyon, section of coal bed near........ 43

Hastings, Nebr., coal tests made at........... 62

Holwell ranch, occurrence of coal at........... 27-30

prospects on, location of, figure showing.. 28 

sample of coal from, analysis of.......... 29,53

sections at............................... 28,29

Inyankara Mountain, supposed coal outcrop

near............................. 24

Jumbo mine. See Cambria.

Lakota sandstone, character and occurrence

of............................... 9-15

exposures of, plates showing............. 10,18

Lincoln Traction Co., boiler tests of coal by... 61 

Little Oil Creek, occurrence of coal on......... 43-44

sandstone exposure on, plate showing.... 10

sections along........................... 11,43

Lupton, C. T., report on Cambria by......... 38-42

Mason Creek, occurrence of coal on........... 24-27

Miller coal mine, development a d section at. 24-25 

Morrison shale, character and occurrence of... 9 

Mount Zion ranch, occurrence of coal near.... 43

opening on coal near, plate showing...... 42

section of Lakota sandstone near......... 12

Newcastle coal, test of....................... 62

Dakota sandstone near, plate showing.... 10

prospects near, figure showing............ 28

stratigraphic relations near.............. 11

65
'66 INDEX.

Oil Creek, stratigraphic relations near........ 13-15

Philpott Canyon, occurrence of coal in........ 25-27

Plum Creek, occurrence of coal near......... 31-32

stratigraphic relations near.............. 12

Producer-gas tests of Black Hills coal, results

of............................... 59

Publications, on Black Hills coal............ 5-6

" Bed beds," character and thickness of..... 9

Rich Hill coal, test of........................ 62

Robbersroost Canyon, coal prospect in...... 44

Salt Creek, coal beds near................... 32,44

Salt Spring, coal bed near................... 32

Sheridan coal, tests of.....................

Skull Creek, occurrence of coal along.......... 27-31

Spearflsh formation, character and thickness

of............................... 9

Spencer prospect, sections at................ 30

Steaming tests, of Black Hillscoal, resultsof.. 58 

Sundance, occurrence of coal near........... 21-24

occurrence of coal near, figures showing... 22,23 

Sundance formation, character and thickness

of............................... 9

Tests, of Black Hills coal, resultsof........... 57-62

Weir-Pittsburgh coal, boiler test of.......... 61

o

*

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