DEPARTMENT OF THE INTERIOR

Roy 0. West, Secretary

U. S. GEOLOGICAL SURVEY 

George Otis Smith, Director

Bulletin 804

GEOLOGY AND COAL AND OIL BESOUECES OF

THE HANNA AND CABBON BASINS,

CARBON COUNTY, WYOMING

BY

C, E, DOBBIN, C, F, BOWEN, AND H. W, HOOTS

UNITED STATES

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1929
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» CONTENTS

I'age

Introduction. __ _______________.___--__.----.---------------------- 1

Location and relations of the area.___________-_---_------------- 1

Purpose of the survey_____________.-----_--------------------- 2

Field work____________________-_-.-_--..----------.----.----- 2

Acknowledgments-._______-___---_---------------------------- 3

Earlier geologic investigations._____--.------------------------- 3

History of mining development.______-_-__---_-__-_------------ 6

Geography.___________________________-_---__-------------------- 6

Surface features..___--_-_.__--__----_----_-------------------- 6

Drainage,.. ________----__-_--_--_----------------------------- 8

Settlements and roads.__.__--_------_----_------_------------- 8

Stratigraphy.,._ _______________________-____--------__-_-__-____-_ 9

General relations.__-_---_-_--_-------------_----_----_------_- 9

Pre-Tensleep rocks.-_----__------_---------------_-------.---- 11

Pennsylvanian rocks..___._-_-_-------------_------------_----- 11

Tensleep sandstone..-.--.--.------------------------------ 11

Permian and Triassic rocks-____________________________________ 11

Embar (?) formation._____________________________________ 11

Chugwater formation._____________________________________ 12

Jurassic rocks..________-___-___-____--.-__ ------__---_-_.__-__ 12

,' Sundance formation...-__..--_.----_-__----.-________.-.... 12

Cretaceous (?) rocks.__________________________________________ 13

Morrison formation._______________________________________ 13

Cretaceous rocks._-_--___,-----_:-------------------------_--- 14

Cloverly formation________________________________________ 14

Thermopolis shale_____----_-_--_----.-._---_-__-_______-_. 15

Mowry shale-____-____-_-___----__-_______-______________ 15

*" Frontier formation___________ .___________..________________ 16

Carlile shale.__-____-___--_--_-_-_--__--_--_______________ 16

Niobrara formation_,____________________________________ 16

Steele shale...____________________________________________ 17

Mesaverde formation_______-..___-__-_-.-_..-_-..-_---._..- 17

Lewis shale _____________________________________________ 21

Late Upper Cretaceous and Tertiary (?) rocks.------------------- 22

General features._________________________________________ 22

' Medicine Bow formation.__________________________________ 23

Tertiary (?) and Tertiary rocks._______._____.______ ____________ 24

Ferris formation._________________________________________ 24

Hanna formation..________________________________________ 25

North Park formation.____________________________________ 26

Quaternary deposits.__________________________________________ 26

Terrace gravel-___________________________________________ 26

Alluvium__---------_--_--_-..---_.._.-,--......._-__.-___ 27
IV CONTENTS

Page

Structure ________________________________________________________ 27

General features. _____-_____________'__________________________ 27

Folds-.-_------_-------___--_______-_---__-_--_-_-_--_-__-___ 27

Fort Steele anticline._--______--___-__-____-___________-___ 27

Walcott syncline__________________________________________ 28

Cedar Ridge, St. Marys, and Pass Creek Ridge anticlines. _____ 28

Saddleback Hills anticline and Carbon Basin _________________ 29

Flat Top anticline _-_-_-__-_._-___--_-.____.____._-__-_._ 29

Faults.-_---_--_-_-------__-_--___-__--_--_-_-_-_--_-_--_-___ 30

St. Marys fault____-________________________________,_____ 30

Cedar Ridge fault------_-----------_---_-----_---------_-- 31

Minor faults _-____-_________-___-__---.-_--_----._--____ 31

Economic geology.___---_-____-____-____-_-____-_--_-._-_-_-______ 31

Coal__-I___-______-____.___________________________---------- 31

General occurrence._______________________________________ 31

Physical and chemical properties.______.____.__.____^_______ 32

Production and uses-_-_______________-_____-__-_-_-_._____ 37

Quantity of coal-_--__-____-_________-__-_-_-_-__-____-_-_ 37

Township descriptions_____________________________________ 38

General scope_________________________________________ 38

T. 21 N., R. 85 W____________________________________ 39

T. 22 N., R. 85 W____________________________________ 40

T. 23 N., R. 85 W_-___-_-_-__-___-_._________________ 42

T. 21 N., R. 84 W__ -.-__-_.__-.--.-.-____.____-______ 42

T. 22 N., R. 84 W.---_-_______-_____--__.____.-_____. 44

T. 23 N., R. 84 W._____._____________________________ 45

T. 24 N., R. 84 W----.--_--__---__------_-_--.------- 48

T. 21 N., R. 83 W-__________________-_-____._________ 50

T. 22 N., R. 83 W_____-_-___--_-__-___-___-_---____-_ 51

T. 23 N., R. 83 W_________.__________________________ 56

T. 24 N., R. 83 W______________---_-_____-__-___-___- 59

T. 21 N., R. 82 W-_________________; ___-_-------_--__- 62

T. 22 N., R. 82 W--________-_-_______.-_______..--___ 62

T. 23 N., R. 82 W. ___________________________________ 66

T. 24N., R. 82 W.__________________________.________ 67

T. 21 N., R. 81 W_--______-_________-_-_----___------ 68

T. 22 N., R. 81 W-__-_______-___________-_.___-_-____ 68

T. 23 N., R. 81 W-______._-_-____-____-_-_---_------_ 73

T. 24 N., Rs. 80 and 81 W.________-__-_-__-__ _______ 76

Tps. 20 and 21 N., R. 80 W________-__-___-____ __ 76

T. 22 N., R. 80 W._________--__---_--------_---_-_-_- 79

T. 23 N., R. 80 W_._________-_________-_-.-_-.--_--_- 81

Tps. 20 and 21 N., R. 79 W-____-__---__-_-_________-_. 82

T. 22 N., R. 79 W_________________-___---_---_-.---_- 84

Oil developments______________________________--_----_---__- 84

History of drilling operations._______________-_-__--_---_-__ ' 85

Fort Steele anticline.__________________________________ 85

Cedar Ridge, St. Marys, and Pass Creek Ridge anticlines.- 85

Saddleback Hills anticline._______________________________ 85

Alien Lake anticline.__________--_____-_-_-_-_----__--_ 86

Oil Springs anticline.__________________________._____'__ 86

Index-___---_-------------_-------_--------------------------- 87
ILLUSTKATIONS

Page 

PLATE 1. A, Tensleep sandstone in the Flat Top anticline, SE. J^ sec.

12. T. 23 N., R. 79 W.; B, Upper part of the Chugwater 

formation on Little Medicine Bow River, SE. }4 sec. 13, 

T. 23 N., R. 79 W__--___--_-----_-_----_--_-_._________ 26

2. A, Sundance, Morrison, and Cloverly formations in Como 

Ridge; B, Morrison and overlying formations on Little 

Medicine Bow River, SW. H sec. 14, T. 23 N., R. 79 W..._ 26

3. A, Mesaverde formation on North Platte River, NW. ^ sec.

13. T. 22 N., R. 86 W.; B, Transition zone from Steele shale 

to the Mesaverde formation, NW. % sec. 24, T. 22 N., R. 

86 W.....-._........_,..._......_....__.........__... 26

4. A, Sandstone hogback in the upper part of the Lewis shale, 

NW. ]>i sec. 2, T. 21 N., R. 84 W.; B, Medicine Bow formation on Austin Creek, SW. % sec. 12, T. 24 N., R. 83 W____ 26

5. A, Upper part of the Ferris formation, NE. % sec. 31, T. 21 

N., R. 83 W.; B, Vertical beds in the lower part of the Ferris 

formation, sec. 18, T. 24 N., R. 82 W........_..._...... 26

6. A, Conglomeratic sandstone at base of Hanna formation, near 

Carbon; B, Hanna formation overlapping Mesaverde sandstone and Steele shale, fi[g. % sec. 4, T. 23 N., R. 80 W...... 26

7. A, Panorama in sec. 9, T. 23 N., R. 80 W., showing steeply 

dipping Hanna rocks striking north toward the Freezeout 

Hills; B, Conglomerate in lower part of the Hanna formation, SE. M sec. 5, T. 21 N., R. 81 W.; C, North Park formation on North Platte River below Saratoga.__.-_.--______ 42

8. Columnar section of rocks exposed in the Hanna and Walcott

q uadrangles___________________________________________ 42

9. A, Mesaverde formation in Saddleback Hills anticline, sec. 17, 

T. 21 N., R. 80 W.; B, Oil Springs anticline in sec. 1, T. 

23 N., R. 79 W.; C, Wilson coal mine, SE. M sec. 32, T. 21 

N., R. 80 W............---_.-.-._.-.-...-_.--...._.... 42

10. Columnar section of rocks exposed in the Saddleback Hills

quadrangle. ___________________________________________ 42

11. Sections of coal beds in T. 23 N., R. 85 W..__-______.__-In pocket12. Sections of coal beds in T. 21 N., Rs. 83 and 84 W.; and T. 22

N., R. 84 W_______._____________._____-_______.__-In pocket.

13. Sections of coal beds in T. 23 N., R. 84 W..___._.__.....In pocket.

14. Sections of coal beds in T. 24 N., R. 84 W._._____._.....In pocket.

15. Sections of coal beds in T. 22 N., R. 83 W.-_._-___-..__-In pocket.

16. Sections of coal beds in T. 23 N., R. 83 W-______._____-In pocket.

17. Sections of coal beds in T. 24 N., R. 83 W_.--_-____-.__-In pocket.

18. Sections of coal beds in Tps. 21 and 22 N., R. 82 W._.___In pocket.

19. Sections of coal beds in T. 23 N., R. 82 W., and T. 24 N., Rs.

80, 81, and 82 W___.______.-________-____.-___In pocket.

v
VI ILLTJSTRATIOISrS

Page 

PLATE^O. Sections of coal beds in T. 22 N., R. 81 W._._-__-_^__._-In pocket.

21. Sections of coal beds in T. 23 N., R. 81 W....._.__.._...In pocket.

22. Sections of coal beds in Tps. 20 and 21 N., Rs. 80 and SlW-.In pocket.

23. Sections of coal beds in T. 22 N., R. 80 W.._.....____..-In pocket.

24. Sections of coal beds in T. 23 N., R. 80 W.._.._._...___.In pocket.

25. Sections of coal beds in Tps. 20, 21, and 22 N., R. 79 W_.Iu pocket.

26. Logs of wells in the Hanna and Carbon Basins._________-In pocket.

27. Geologic map and structure sections of the Hanna and Carbon

Basins.__________________________________________ _In pocket.

FIGURE 1. Map of southern Wyoming showing relation of Hanna and

Carbon Basins to other coal and oil and gas fields..____._. 1

2. Sections of coal beds in T. 21 N., R. 85 W.._._____________ 39

3. Sections of coal beds in T. 22 N., R. 85 W....-_..--__--_-- 41.

V,
GEOLOGY AND COAL AND OIL RESOURCES OF THE 

HANNA AND CARBON BASINS, CARBON COUNTY, WYOMING

By C. E. DOBBIN, C. F. BOWEN, and H. W. HOOTS

INTRODUCTION

Location and relations of tlie area. The Hanna and Carbon Basins 

lie in south-central Wyoming (see fig. 1), and are due to the existence of great basin-shaped depressions in the earth's crust that have 

been filled by layers of sandstone and shale interbedded with many

no'

FIOUKB 1. Map of southern Wyoming, showing relation of Hanna and Carbon Basins 

to other coal and oil and gas fields. 1. Rock Creek oil field (U. S. Geol. Survey Bull. 

806) ; 2, east central Carbon County (Bull. 316) ; 3, Lost Soldier-Ferds district 

(Bull. 756) ; 4, Bell Springs gas field (Bull. 796) ; 5, Great Divide Basin coal field 

(Bull. 341) ; 6, Little Snake River coal field (Bull. 341, 381) ; 7, Rock Springs 

district (Bull. 341, 381, 702, 751, 781)

layers of coal. Extensive coal-mining operations have long been in 

progress in these basins, and their coal-bearing areas are traversed 

by the main line of the Union Pacific Railroad, their great remaining 

reserves of coal being thus made readily available at such future times 

as they may be in greater demand.

The two basins are really subdivisions of a single major downwarp 

of the granitic basement rocks of the region that lies between the 

Rawlins uplift on the west, the Ferris, Seminoe, Shirley, and Free/eont uplifts on the north, and the Medicine Bow uplift on the south.

1
2 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

This depression is not closed on the east by an}' definite structural 

feature but represents the accentuated northwestward extension of 

the broad intermontane syncline known as the Laramie Basin. The 

depth of the depression is such that it contains about 35,000 feet of 

sedimentary rocks ranging in age from Carboniferous to late 

Tertiary.

The Hanna and Carbon Basins are almost wholly covered by the 

topographic maps of the Walcott, Hanna, and Saddleback Hills 

quadrangles, but they also include about one tier of townships north 

of these quadrangles, which has not been mapped topographically. 

The Union Pacific Railroad crosses the three quadrangles, and all 

of the area described, except the northern portions of T. 24 N., Rs. 

82 to 84 W.. and T. 23 N., R. 85 W., is within 15 miles of the railroad.

Purpose of the survey. The geologic investigations that form the 

basis for this report were undertaken primarily for the purpose of 

classifying and valuing the public land with regard to coal. In 

order to do this it was necessary to locate accurately with respect to 

land lines the outcrops of all coal beds that were considered to be 

of workable thickness. The thickness and the character of the coal 

beds were determined in all accessible mines and prospects, and in 

the absence of openings sufficient prospecting was done to obtain the 

desired information. The quality of the coal was determined by 

analyses of fresh samples taken from working mines, or from prospects that had been recently opened. The geologic structure of the 

field was worked out with considerable accuracy in order to determine 

the depth of the coal beds below the surface and their availability for 

mining.

Field work. The investigations forming the basis for this report 

were made during the field season of 1913 by C. F. Bowen, assisted 

by F. A. Herald, F. A. Hinkley, L. H. White, Fritz Aurin, and for a 

time by J. B. Reeside, jr., and in 1915 by Mr. Bowen with the assistance of C. J. Hares, C. A. Bonine, H. M. Robinson, O. L. Brace, and 

V. O. Wood. A brief inspection of the field was made by C. E. 

Dobbin in 1924, and was followed by a more thorough field review 

and slight revision of the geologic data by" Mr. Dobbin and H. W. 

Hoots in 1925. Statistics of development were revised to include all 

explorations for coal and oil to the end of 1925. The present report 

was then prepared by Mr. Dobbin with the assistance of Mr. Hoots.

The original mapping was done by means of plane table and telescopic alidade, used in conjunction with a topographic base having 

a horizontal scale of 1: 48,000 and a contour interval of 25 feet. This 

base and a system of triangulation established during the topographic survey served as both horizontal and vertical control except 

for that portion of the area lying north of the quadrangles, which
INTRODUCTION 3

was mapped on a fiat base, on which horizontal control was obtained 

b,y expanding the triangulation net established in the quadrangles.

During the season of 1913 altitudes were determined at all locations made on coal outcrops but not on geologic boundaries, as it was 

found that the topography is sufficiently precise to give the altitude 

of these boundaries. In general, the altitudes of coal beds computed 

from the topographic contouring vary less than 25 feet from the 

true altitude, and the variation rarely exceeds 50 feet.

During the progress of the topographic mapping the land survey 

was adjusted to the triangulation control by the location of many of 

the land corners. The topographic base, therefore, serves as well 

for the determination of cadastral position as for the determination 

of surface altitudes. During the geologic examination many of the 

land-corner stones were located for the purpose of " tying " coal beds 

to them. Most of the corners thus located harmonize with the land 

net on the topographic map. Only a few of the corners for \vhich 

careful search was made could not be found.

Acknowledgments. The writers wish to acknowledge the efficient aid rendered by all assistants during the prosecution of the 

Avork. They also Avish to tender especial thanks to Eugene McAuliffe 

and G. B. Pryde, officials of the Union. Pacific Coal Co., for maps, 

drill-hole records, and development data in the Hanna district; 

to Elfred Beck, of the Producers & Refiners Corporation for log? 

of wells on the Saddleback Hills and St. Marys anticlines; to 

Albert Cronberg, of Medicine Bow, for information concerning the 

geology and oil developments near that town; to T. W. Stanton, F. 

H. Knowlton, and J. B. Reeside, jr., for their identification and interpretation of fossils; and to M. R. Campbell and W. T. Thorn, jr., 

for their supervision of the investigations and for suggestions and 

criticisms offered during the preparation of this report.

Earlier geologic investigations. The earliest geologic investigations in the Hanna and Carbon Basins were made by Hadyen in 

1868, and in describing the country along the Union Pacific Railroad west of Como Ridge he wrote: x

From a point about 10 miles east of Coino to St. Marys Station, a distance 

of about 50 miles, the Tertiary formations occupy the country with the 

peculiar sands and sandstone and clays and numerous coal beds. The most 

marked development of the coal beds is at the Carbon station, about 80 miles 

west of Laramie station. The rocks incline nearly southeast, or south and 

east. Three entrances have been made to the mine, and the bed is 9 feet 

thick. The openings follow the dip and consequently descend. The mines 

are about 3,000 yards from the railroad, but a sidetrack has already been 

laid to them. More than 1,000 tons of coal have already been taken, and 

the Union Pacific Kailroad Co. is ready to contract for any amount that

1 ITayclen, P. V., LJ. 8. Geol. Survey Terr. Second Ann. Kept., pp. 95-96. 1873.
4 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

can be supplied to them. The coal at Carbon is of the best quality of Tertiary splint, very compact and pure. It is not as hard as anthracite, but the 

miners informed me that it was more difficult to work than the bituminous 

con Is of Pennsylvania. * * *

From St. Marys to Rawlings Springs, a distance of about 30 miles, the 

railroad passes over rocks of Cretaceous age. * * * The railroad, from a 

point about 8 miles east of Ben ton to Rawlings Springs, passes through one of 

the most beautiful anticlinal valleys I have seen in the West. On either side 

the rusty-gray sands and staudstones dip away from the line of the road at an 

angle of 10° to 15°. This anticlinal valley is most marked near Fort Steele. 

at the crossing of the North Platte.

In the early surveys of the fortieth parallel King 2 subdivided the 

Cretaceous into four major " groups " Dakota, Colorado, Fox Hill, 

and Laramie. The Colorado group was in turn subdivided into the 

Fort Benton, Niobrara, and Fort Pierre groups, corresponding respectively, to Meek and Hayden's Cretaceous Nos. 2, 3, and 4. The 

Fort Pierre, now known as Pierre shale, was later excluded from the 

Colorado group when the Montana group was defined.

In his report King states:

The whole Colorado group, composed of these three members, is bounded 

on the upper surface by the heavy sandstones of the Fox Hill and below by 

the still more compact sandstones of the°Dakota.

It is evident from King's description of the Fox Hill " group " 

that sandstones of the Hanna Basin region now included in the 

Mesaverde formation were considered by him and other early workers as at least a part of that " group." King states further: 3

In the region of Carbon the Fox Hill sandstones are very well developed 

and dip from every direction inward toward the town. To the southwest they 

are well exposed in Simpsons Ridge [Saddleback Hills], where they rise 800 

feet above the village. * * *

A section across the ridge on the western side of the Platte, south of Fort 

Steele, shows that the lower 2,000 feet are pricipally beds of massive sandstone, 

50 or 100 feet thick, with but very little shale. Above these are about 1,500 feet 

of more thinly bedded sandstones, whose individual members vary from 5 to 15 

feet in thickness and contain a great many interlaminated shales, which are 

often bituminous, and thin seams of coal. In the valley south of the ridge, 

south of Fort Steele, the younger sandstones are decidedly ferruginous, show a 

considerable change of character, and are supposed to represent the bottom of 

the Laramie. The entire Fox Hill here is estimated at about 3,500 feet.

It appears that the thick marine shale above the Mesaverde formation now known as Lewis shale was not recognized by the early 

workers in this region as being in that position.

In the period between 1867 and 1873 Arnold Hague,* geologist of 

the Fortieth Parallel Survey, examined and described the Carbon

2 King, Clarence, Systematic geology: U. S. Geol. Expl. 40th Tar. Kept., vol. 1, pp. 

305-306, 1878.

3 Idem, pp. 322-323. .

4 Hague, Arnold, Descriptive geology: U. S. Geol. Expl. 40th Far. Kept., vol. 2, pp. 

142-155, 1877.
INTRODUCTION 0

Basin and adjoining mountains, foothills, and plains regions, from 

Como station westward to the vicinity of Fort Steele. At about this 

time Lesquereux identified fossil plants collected by Hayden in Carbon Basin and interpreted them as lower Miocene.5 Lesquereux was 

largely responsible for our first knowledge of the fossil plants of 

the western Tertiary formations. He was early occupied in the identification of fossils collected and submitted by Hayden in his earliest 

explorations, but later, in 1872, at the direction of Hayden, he took 

the field for the purpose of obtaining sufficient fossil plants to determine the age of the lignitic formations. He visited Carbon and collected numerous specimens, which he tabulated/'1 Newberry 7 also 

examined and identified fossil plants collected by geologists of the 

early surveys.

F. B. Meek, intimately associated with Hayden in early explorations of the West, acted as paleontologist for the Geological Survey 

of the Territories and was one of the recognized authorities on 

invertebrate fossils of North America. Working actively in a virgin 

field, Meek collected and described great numbers of invertebrate 

fossils from formations of the West ranging in age from early 

Paleozoic to the Tertiary. Accompanied by H. M. Bannister in 1872 

he examined coal-bearing rocks exposed along the Union Pacific 

Railroad in southern Wyoming for the purpose of collecting fossils. 

Invertebrate forms were collected from localities east and west of the 

Carbon and Hanna Basins, but with the exception of some specimens 

of Ostrea found in the Niobrara shale near Fort Steele, no invertebrates were collected from the area described in this report.

One of the first reports on the Tertiary coals of the West was that 

by James T. Hodge, geologist on Hayden's early survey. The introduction to this report gives the following historical account 8 of the 

conditions prevalent in the West at about the time of the first coal 

mining in this region:

The occurrence of coal in the Rocky Mountains was observed and reported 

on by most of the early explorers on the different routes they traversed across 

the continent. Little importance, however, was attached to these discoveries, 

and, as the coal beds were seen only in their outcrop, little knowledge was 

acquired of their real character. It was understood that they belonged, not to 

the true coal formation, but either to the Lower Tertiary or Upper Cretaceous. 

and the coal was consequently classed among the lignites or brown coals and 

generally considered to be far inferior in quality to the genuine coals of the

5 Lesquereux, Leo, Tertiary flora of North America: U. S. Geol. Survey Terr. Fiftli 

. Ann. Kept., pt. 3, p. 306, 1872.

0 Lesquereux, Leo, Lignitic formation and fossil flora: U. S. Gcol. Survey Terr. Sixth 

Ann. Rept, pp. 410-417, 1873.

7 Newberry, J. S., The later extinct floras of North America: U. S. Geol. Survey 

Mon. 35, 1898.

8 Hodge, J. T., On the Tertiary coals of the West: U. S. Geol. Survey Terr. Fourth 

Ann. Kept., pt. 4, p. 318, 1871.
6 HANNA AND CARBON" BASINS, CARBON COUNTY, WYO.

Eastern and Middle States. As the country began to be settled, the scarcity of 

timber soon caused these deposits of fuel to be looked up and mines of coal to 

be opened and worked in Utah and in Colorado. The construction of the Union 

Pacific and Central Pacific Railroads created a still greater demand for fuel 

for the supply of their locomotives, and new mines were opened along the line 

of the former road in Wyoming Territory, which, with those worked on the 

eastern border of Utah, near the same road, supply both these long lines of 

road with all the coal they require. No mines have been found near the Central 

Pacific Railroad, either in Utah, Nevada, or California, so that this road is 

wholly dependent for fuel upon the coals brought to it from the Union Pacific. 

Though it is scarcely three years since these coal mines began to be developed, 

they have already produced large quantities of coal, and several among 

them have the appearance of thriving collieries, well furnished with powerful 

machinery for pumping and hoisting and all the appliances of first-class 

establishments.

More recently Veatdi 9 located and collected samples from the coal 

mines of the Hanna and Carbon Basins and prepared a reconnaissance 

geologic map covering these basins and some adjacent territory.

History of mining development. The first coal-mining development in the Hanna and Carbon Basins was that at and near the 

town of Carbon in 1868. Seven mines were ultimately opened at 

this place, and the production up to and including 1902, when the 

mines were abandoned, was about 4,680.000 tons. The immediate 

cause for the abandonment of these mines was the shifting of the 

main line of the Union Pacific Railroad farther north to its present 

route through the town of Hanna. Mines at Dana were opened in 

1889 and abandoned in 1891, according to reports, on account of the 

unsuitability of the coal for locomotive use. The mines at Hanna 

were opened in 1890.

Five mines, known as Nos. 1. 2, 3, 8^2> and 4, have been opened by 

the Union Pacific Coal Co. at Hanna, and of these, Nos. 2 and 4 

are actively operated at the present time. These two mines employ 

250 men and have an average daily production of 2,200 tons of coal.

GEOGRAPHY

Surface features. The plains type of topography prevails in the 

Hanna and Carbon basins but is broken around their margins by 

low ridges composed, in most places, of the resistant sandstones of 

the Mesaverde formation. These ridges reach a maximum altitude 

in Pass Creek Ridge, in the Hanna quadrangle, of 7,905 feet above 

sea level. High plains in various stages of erosion, terraces formed 

by streams when they flowed at higher levels than now, alluvial 

flats as much as half a mile wide, and valleys of moderate extent all 

occur within these basins. The extreme range of relief within the

9 Veatch, A. C., Coal in east-central Carbon County, Wyo.: U. S. Geol. Survey Bull. 316, 

pp. 244-260, 1907.
GEOGRAPHY 7

urea is about 1,600 feet, between the crest of Pass Creek Ridge and 

Nori h Platte River at the point where it leaves the area.

The plains, which occupy the greater part of the area, have locally 

been carved into prominent isolated hills, the most conspicuous of 

which occur in the vicinity of Hanna, and striking examples of badland topography are developed along the coulees leading down to 

Medicine Bow River.

Pass Creek, St. Marys, and Cedar Ridges form a nearly continuous 

chain of hills, separated into three parts, which extend from northwest to southeast across the southwestern parts of the Walcott and 

Hanna quadrangles. In previous publications these hills-have been 

described under a single name, chosen from one or another unit of the 

chain, but to avoid confusion local names applied to the individual 

units are here adopted. These ridges are bold rocky features that 

rise rather abruptly, in places almost precipitously, from the surrounding plains. The maximum altitude is attained in Pass Creek 

Ridge, whose highest point rises about 750 to 900 feet above the 

adjacent plains.

Rattlesnake Ridge lies southwest of St. Marys and Cedar Ridges, 

to which its trend is approximately parallel. This ridge rises by a 

series of southwestward-f acing escarpments from the valley of North 

Platte River to a maximum height of nearly 1,100 feet above the 

river level. On the northeast it descends by a more gentle and uniform slope to the broad valley which separates it from St. Marys and 

Cedar Ridges.

The Saddleback Hills, in the southern part of the Saddleback 

Hills quadrangle, form a bold, narrow ridge, which rises to a maximum altitude of 7,843 feet, or about 500 to 600 feet above the surrounding plain, and part of a similar but broader ridge, known as 

Medicine Bow Ridge, occupies the extreme southeast corner of the 

same quadrangle.

With the exception of the series of prominent hogback ridges east 

" of Medicine Bow River in the northeast corner of the Saddleback 

Hills quadrangle and some of the high ridges along the northern 

margin of the Hanna Basin, the remainder of the area described is 

featured by undulating plains from 6,500 to 7,500 feet above sea 

level. In their higher portions, as in the northeast quarter and along 

the north edge of the Hanna quadrangle, they are rough and broken, 

and the descent to the valley of Medicine Bow River is extremely 

abrupt and rugged.

Flat-topped gravel terraces, remnants of a former more extensive 

terrace system, border the valleys of North Platte and Medicine 

Bow Rivers in many places, and a series of lower terraces occur 

within the present river valleys.
8 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

Alluvial flats as much as half a mile in width occur along North 

Platte and Medicine Bow Kivers and to a lesser extent along some of 

the larger intermittent drainage channels.

Dramage. The Hanna and Carbon Basins lie wholly within the 

drainage basins of the North Platte and of its tributary Medicine 

Bow River, and the perennial streams joining these rivers within the 

basins are Little Medicine Bow River and Austin, Troublesome, and 

Difficulty Creeks, which rise in the Shirley Mountains, on the north. 

The surface drainage reaches the permanent streams through intermittent stream channels locally known as ditches.. Hanna Ditch 

rises in the hilly area northeast of Hanna and pursues a, northeastward course to Medicine Bow River. Walcott Ditch begins in the 

southwestern part of the Saddleback Hills quadrangle and follows a 

general westward course past Dana and Walcott to North Platte 

River at Fort Steele. St. Mary's Ditch rises in the east-central part 

of the "Walcott quadrangle and follows a northwestward course to 

North Platte River. The best known and most prominent of these 

ditches is Big Ditch and its two tributaries, North and Middle 

Ditches. Big Ditch rises near the eastern boundary of the Hanna 

quadrangle east of Hanna, and* follows a general northwestward 

course to North Platte River, which it enters 3 miles south of the 

north boundary of the Walcott quadrangle. Middle Ditch and 

North Ditch have general westerly courses. These three ditches 

drain approximately three-fourths of the area of the Walcott and 

Hanna quadrangles.

Settlements atiid roads. The Union Pacific Railroad crosses the 

Hanna and Carbon Basins and is the principal cause of their settlement. The town of Hanna has been built around the coal mines 

opened to provide locomotive fuel and now (1926) has a population 

of about 1,800. Medicine Bow, with a population of about 200, is 

also on the railroad about 3 miles east of the area, and Walcott and 

Fort Steele contain about 75 and 150 people, respectively, and serve 

principally as supply points for near-by ranches. A branch railroad 

extends southward from Walcott to Saratoga and Encampment. 

With the exception of the towns and of the ranches on the alluvial 

flats of North Platte and Medicine Bow Rivers and Austin Creek, 

the area is sparsely settled, largely because of the scarcity of water.

The Lincoln Highway traverses the southern portion of the area, 

and well-traveled roads lead from it both north and south to distant 

towns, ranger stations, and ranches in the well-watered mountainous 

areas adjoining the basins. One such road traverses the northeast 

corner of the Saddleback Hills quadrangle, crosses Medicine Bow 

River, and leads to Difficulty post office, in the Freezeout Hills. Difficulty is also reached by a well-traveled road that leads north from
STEATIGKAPHY

Hanna. Another good road leads from Medicine BOAV southwestward 

across the southeast corner of the Saddleback Hills quadrangle to the 

Johnson ranch, on Medicine Bow River, and thence to the town of Elk 

Mountain. Another well-traveled road leads north from Walcott, 

skirts the east end of St. Marys Ridge, crosses Medicine Bow River 

in sec. 26, T. 24 N., R. 83 W. and proceeds northward to the Freezeout Hills and Casper. Other roads and trails exist within the area, 

and some are fairly well traveled at certain times of the year, though 

they are as a rule in poor condition.

STRATIGRAPHY

GENERAL RELATIONS

The consolidated formations exposed in the Hanna and Carbon 

Basins are all of sedimentary origin and range from Triassic to Tertiary in age. They include marine, fresh-water, and brackish-water 

deposits having an aggregate thickness of about 33,650 feet, although 

some of the formations are separated by pronounced unconformities. 

Unconsolidated deposits of small extent and of fluviatile and eolian 

origin also occur.

Beneath the strata that crop out in the area mapped are older 

formations of sandstone, shale, and limestone, Avhich date back to 

Carboniferous and possibly to Cambrian time. These formations 

are upturned and exposed by erosion along the mountain ranges surrounding the Hanna and Carbon Basins and rest unconformably on 

pre-Cambrian crystalline rocks, including granite, gneiss, and schist, 

which constitute the cores of most of the mountain ranges.

Geolot/ic formations in the Hanna and Carbon Baxhi-s, Wi/o."

Age

Quaternary.

Miocene (?) .

Eocene.

Formation

Alluvium.

Terrace gravel.

North Park formation.

-Unconformity 

Hanna formation.

Thickness 

(feet)

4 0-25

'0-400

" 7, 000

Characteristics

Worked-over material from surrounding formations.

Waterworn pebbles of older sedimentary and crystalline 

rocks.

Whitish unconsolidated sand and clay with thin intercalated beds of limestone in 'some places; locally conglomeratic at base.

Alternating beds of dark-gray, yellowish, and carbonaceous 

shale; white, gray, and brown sandstones, massive to 

thin bedded and commonly cross-bedded; conglomerate 

 and conglomeratic sandstone containing pebbles of 

chert, granite, quartzite, sandstone, Mowry shale, Cloverly conglomerate, etc.; and numerous beds of coal. Contains fish scales, bones of turtles and mammals, freshwater shells, and an abundance of leaves.

 Bowen, C. F., Stratigraphy of the Hanna Basin, Wyo.: U. S. Oeol. Survey Prof. Paper 108, pp. 228-229, 

1917. [With some changes.] 

6 Approximate.
10 HANNA AND CARBON BASINS, CAEBON COUNTY, WYO. 

Geologic formations in the Hanna and Carbon Ba-skis, Wyo. Continued

Age

Upper Cretaceous.

Lower Cretaceous.

Cretaceous (?).

Upper Jurassic.

Triassic.

Permian.

Pennsylvanian.

Formation

Ferris formation.

Medicine Bow 

formation.

Lewis shale.

Mesaverde formation.

Steele shale.

Niobrara formation.

Carlile shale.

Frontier formation.

Mowry shale.

Therm o p o 1 i s 

shale.

Cleverly formation.

Morrison formation.

Sundance formation.

Chugwater formation.

Embar (?) formation.

Tensleep sandstone.

Thickness 

(feet)

/

' 6, 500

» 4,000- 

6,200

*3,300

2,200- 

2,700

' 4,000- 

5,000

*700

» 460

'725

120

180

128

350

350

1,300

150

&250

Characteristics

Light-colored, dark-gray, and carbonaceous shale; buff to 

brown sandstone, in places extremely cross-bedded and 

showing great irregularity of deposition; and numerous 

beds of coal. Pockets, lenses, and thin beds of conglomerate composed of pebbles of older rocks are distributed 

through a zone about 1,000 feet thick at the base of the 

formation. Contains fresh-water invertebrates, land

ing Triceratops.

Light-colored to gray and carbonaceous shale; gray to brown

features of irregular deposition; thin irregular beds of coal 

and sandstone containing marine Cretaceous fossils in 

lower part. Fresh and brackish water invertebrates, 

land plants, and bones of dinosaurs, including ceratopsians.

Predominantly dark-gray shale with thin intercalated beds 

of shaly sandstone and some beds of light-colored massive 

to heavy-bedded sandstone. About 600 feet below the 

top of the formation is a persistent ledge-making gray 

sandstone about 270 feet thick. Marine.

An upper member of white to gray sandstone alternating 

with gray and carbonaceous shale with a conspicuous, 

resistant white sandstone at the top; contains thin irregular beds of coal in some places. A middle member of 

brown to gray sandstone, gray to carbonaceous shale, and 

thin irregular beds of coal; differs from upper member in 

its prevailingly brown color; fresh and brackish water 

fauna. A lower member of gray to white sandstone and 

gray shale; contains a marine fauna and is not coal-bearing; grades into the Steele shale through a zone of transition beds.

Dark-gray shale with intercalated beds of sandy shale and 

sandstone, some of which form conspicuous ledges near 

top of formation. Shale contains concretions of calcareous sandstone, dark limestone, and white crystalline 

calcite. Marine fauna. At top a transition zone of interbedded sandstone and shale.

Dark calcareous shale with several harder chalky beds 

which crop out as conspicuous light-colored ridges.

Dark shale with some thin sandy layers and many large 

concretions.

Dark-gray to black shale with Wall Creek (?) sandstone 

member at top.

Hard, compact dark-brown to black fissile shale weathering 

to silver-gray.

Dark-gray to black shale with thin sandy beds.

An upper member of hogback-forming sandstone, a middle 

member of green shale and sandstone, and a lower member of conglomeratic sandstone.

Variegated shale alternating with sandy shale and sandstone. Contains dinosaur bones.

Gray and green shale alternating with gray sandstone and 

sandy shale.

Bed shale with intercalated red and gray sandstone and 

sandy shale; some limestone and gypsum. Beds of variegated colors are present.

Red shale, limestone, gypsum, and some thin sandstones.

Massive to thin-bedded and cross-bedded light-gray sandstone.

* Approximate.
STEATIGEAPHY H 

PEE-TENSLEEP BOCKS

The oldest sedimentary formation in this general region is a 

well-bedded rusty quartzite which is conspicuously exposed in the 

Rawlins uplift. At Kawlins this quartzite 'is 412 feet thick and is 

considered to belong to the lower part of the Middle Cambrian.

The name Casper formation was proposed by Darton 10 for the 

limestone, dolomite, and sandstone of Carboniferous age, which range 

from 500 to 1,000 feet in thickness and constitute the greater part 

of the sedimentary rocks in the Casper and Laramie Mountains. 

These rocks, according to Darton, represent the southeastward extension of the Amsden and Tensleep formations of central 'Wyoming 

but are so changed in character and indefinite in stratigraphic limits 

that a new name was given to them. Darton recognized, however, 

that in some places, as in the Freezeout Hills, the Madison, Amsden, 

and Tensleep formations can be differentiated. According to Darton, the Casper formation rests unconformably on pre-Cambrian 

crystalline rocks in the Laramie Basin. At Rawlins, however, it 

is in contact with the Madison limestone, which rests on Cambrian 

quartzite.

PENNSYLVANIAN BOCKS

TENSLEEP SANDSTONE

The Tensleep sandstone is conspicuously exposed in sec. 12, T. 23 

N., R. 79 W., and vicinity, where it is the central formation in the 

Flat Top anticline. It is at least 250 feet thick and consists of massive to thin-bedded and cross-bedded light-gray sandstone, which 

stands about 500 feet above the surrounding country and bears a 

growth of pine trees. (See pi. 1, A.)

PEBMIAN AND TBIASSIC BOCKS 

EMBAR ( ?) FORMATION

Excellent exposures of the Embar (?) and the overlying ChugAvater formation occur on the south limb of the Flat Top anticline 

in sec. 13, T. 23 N., R. 79 W., and vicinity, where the moderately 

inclined rocks have been deeply dissected by Little Medicine Bow 

River and its tributaries. Here as elsewhere in this general region 

the line of demarcation between the Embar (?) and Chugwater 

formations is not a sharp one, and for present purposes it was drawn 

at the top of the uppermost thin but persistent limestone above the 

Tensleep sandstone. This limestone probably corresponds to the

10 Darton, N. H., Paleozoic and Mesozoic of central Wyoming: Geol. Soc. America Bull., 

vol. 19, p. 418, 1908.

6175 29 2
12 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

Forelle limestone, and the beds below it to the Satanka shale.11 The 

following section illustrates the character of the Embar (?) formation at this locality:

Section of Enibar (?) formation in sec. 18, T. 23 N., R. 79 W.

Base of typical red beds of Chug water formation. 

Embar (?) formation: Feet 

Forelle (?) limestone Limestone, lavender-colored___ 3 

Satanka (?) shale 

Shale, red _________________________ 85 

Limestone, gray, slabby__________________ ' 10 

Shale, green and brown__________________ 30 

Gypsum _____________________ _ 6

Shale, grayish brown_____________________ 6 

Sandstone, gray, calcareous; contains thin laminae of

asphalt and gives a strong odor of petroleum____ 2

Shale, gray_________________________ 4

Top of Tensleep sandstone. 

146

CIIUGWATER FORMATION

The most characteristic feature of the Chugwater formation is its 

predominantly red color, but other light colors, including purple, 

pink, blue, green, and buff, occur. The formation consists chiefly 

of shale, in part sandy, in which occur beds of sandstone, limestone, 

and gypsum. Beds of sandstone are most abundant in the upper 

part of the formation, and at the top there is a zone 150 feet thick 

consisting almost wholly of sandstone which contains an abundance of 

cross-bedding, ripple marks, and other features characteristic of 

stream, wave, or wind action. (See pi. 1, B.) Gypsum occurs 

chiefly in the lower half of the formation in beds 1 to 19 feet thick. 

In a stratigraphic section measured in the northeast corner of the 

Saddleback Hills quadrangle it is estimated that the Chugwater 

formation consists of 69 per cent shale, 22 per cent sandstone, 6 per 

cent gypsum, and 3 per cent limestone. Its thickness in this area 

is about 1,300 feet.

JURASSIC BOCKS 

STTNDANCE FORMATION

In the Saddleback Hills quadrangle the Sundance formation consists chiefly of gray and green shale with beds of sandstone of varying thickness in its basal and middle portions. In near-by areas, 

however, it contains a greater proportion of sandy beds, including

11 Darton, N. H., and Siebenthal, C. E., Geology and mineral resources of the Laramie 

Basin, Wyo.: U. S. Geol. Survey Bull. 364, pp. 20-22, 1909.
STRATIGRAPHY 13

thin sandstones and arenaceous shales, and thin beds of limestone, 

.some of which are rather sandy.

The following section measured at Como Ridge, 5 miles east of 

Medicine Bow, where exposures are excellent, shows the general' 

character of the Sundance formation in this general region. (See 

pi. 2, A.)

Section of Sundance formation at Como Ridge

Base of Morrisou formation.

Sundance formation: Feet 

Sandstone, gray, cross-bedded________________ 2 

Sandstone, green, shaly______________._______ 5

Sandstone, light gray, cross-bedded___________ 5 

Shale, green, sandy, and thin limestones_________ 34 

Sandstone, buff, thin-bedded_________________ 5 

Shale, green, containing Betemnites____________________ 68

Sandstone, grayish-brown, thin-bedded ____________ 12 

Shale, gray, sandy _ __ _ 29 

Sandstone, light gray, cross-bedded ____________ 7 

Sandstone, gray, massive to thin-bedded and crossbedded_____________________________ 70 

Shale, green_________________________ 15

Shale, red, and thin-bedded red sandstone________ 36 

Sandstone, gray, massive, friable______________ 15 

Shale, green, and shaly sandstone- ______ __ 12

Sandstone, light gray, massive, with brown sandstone 

concretions, cross-bedded in upper part________ 35

Top of Chugwater formation. 12 350

The following marine Jurassic fossils were collected from the Sundance formation in the SW. % sec. 13, T. 23 N., R. 79 W., Saddleback 

Hills quadrangle, locality 9357 :

Penatcrinus asteriscus Meek and Hayden.

Serpula sp.

Eumicrotis curta (Hall).

Trigonia quadrangularis Hall and Whitn'eld.

Tancredia sp.

Pleuromya subcompressa Meek.

Cardioceras cordiforme var. distans Whitfleld.

Belemnites densns Meek and Hayden.

CRETACEOUS (P) ROCKS 

MORKISON FORMATION

The Morrison formation consists of alternating beds of shale and 

sandstone. The sandstone is most abundant in the lower part of the

12 Darton (op. cit., p. 26) obtained 119 feet for the thickness of the Sundance formation 

In Como Ridge, drawing the base of the formation considerably higher than in the section 

given here.
14 HANNA AND CAEBON BASINS, CARBON .COUNTY, WYO.

formation, and at its base there is white sugary massive sandstone 

143 feet thick. Not far above this is another sandstone containing 

conglomerate pebbles at the base and numerous clay balls above. It 

is cross-bedded and ranges from 10 to 34 feet in thickness within a 

few hundred feet along the strike. The shales vary in color from 

green to gray and drab. In other places they show a great variety 

of color and contain maroon members, which make the formation: 

difficult to distinguish from the Chugwater. On lithologic evidenceit is difficult in some places to locate the boundary between the Morrison and the Sundance, and in deciding on what shall be taken as 

the boundary it is necessary to be guided by the character of the contained fossils. Two species of marine invertebrates Belemnites 

densus and Pentacrinm asteriscus are very common in the Sundance, whereas the Morrison contains fresh-water mollusks and bonesof dinosaurs.

Section of Morrison formation on Little Medicine Bow River in sec 14,

T. 23 N., R. 79 W.

Base of Cloverly formation.

Morrison formation: Feet 

Shale, gray to drab, becoming darker at top________ 63 

Calcareous concretionary layer.______________ 3

Shale, pale green_____________--_________________ 24

Sandstone, brown, coarse, cross-bedded____________ 12 

Shale, green ___________________________ 24 * 

Sandstone, brown, thin bedded; contains many clay balls

and bones; locally cross-bedded and variable in thickness. 34 

Shale, green, sandy, and thin beds of sandstone______ 45 

Sandstone, white, shaly; in places sugary, elsewhere

platy______________________________ 143 

Top of Sundance formation. 

348

At Como Ridge the Morrison formation is 222 feet thick and is 

made up almost entirely of variegated shale with thin sandstones. 

(See pi. 2, A.)

CRETACEOUS BOCKS 

CLOVERLY FORMATION

The Cloverly formation is 128 feet thick on Little Medicine Bow 

River in sec. 14, T. 23 N., R. 79 W., and is made up of three members. 

The uppermost member is a heavy sandstone 85 feet thick which 

makes a prominent hogback. (See pi. 2, B.) The middle member, 

which is 33 feet thick, consists of green shale and sandstone, and the 

basal member is a conglomerate 10 feet thick.
STRATIGRAPHY 15

Section of Cloverly formation in sec. .///, T. 23 N., R. 79 W.

Base of Thermopolis shale.

Cloverly formation: Feet 

Sandstone, light gray, hard, sugary, fine grained, locally 

both massive and cross-bedded; conglomeratic; makes 

the prominent hogback shown on Plate 2, B- ___________ 85

Largely concealed but shows scattered exposures of green

shale_____________________-.______ 25 

Sandstone, conglomeratic and very hard 2 

Green shales and greenish-gray sandstone; both soft__ 6 

Sandstone, light gray, cross-bedded, conglomeratic, the pebbles consisting of chert and jasper. ___ ______ 10

128

As no fossils were obtained from the Cloverly formation in this 

area no new evidence can be presented regarding its age. According to Darton 13 it is equivalent to the Lakota, Fuson, and Dakota 

formations of the Black Hills region.

THERMOPOLIS SHALE

The Thermopolis shale consists chiefly of dark-gray to -black shale 

but also contains some thin sandstone layers which commonly show 

markings resembling worm trails. Dark siliceous concretions or 

concretionary bands are also present. The total thickness, as determined at the locality shown on Plate 2, B, is 180 feet.

Section of Thermopolis shale in sec. 14, T. 23 N., R. 79 W.

P>ase of Mowry- shale.

Thermopolis shale: Feet 

Shale, gray to black with several thin papery sandstones 130 

Sandstone, brown, cross-bedded_______________ 4

Shale, gray, sandy____________ _ ___ 10

Sandstone, rusty, hard; makes small hogback (see pi. 2, B). 10 

Shale, black ___________________________ 26

Top of Cloverly formation. ~180

MOWRY SHALE

The Mowry shale is a hard, highly compact deep-brown to black 

fissile shale, 120 feet thick, which has a silver-white color when 

weathered and contains an abundance of fossil fish scales. The fact 

that samples of the shale yield a small amount of oil on distillation 

may have an important bearing on the source of the oil found in 

many places in the Frontier formation.

The Mowry is much more resistant than the shales above and below 

it and usually crops out in a prominent pine-clad ridge. This char-

» Op. cit.. p. :',i.
16 HANNA AND CARBON BASINS, CAKBON COUNTY, WYO.

acteristic, together with those enumerated above, makes it the most 

easily recognizable and useful horizon marker among the formations 

exposed in the area. It is especially used as a datum plane in establishing correlations between different fields, but it is seldom recognized by well drillers and consequently is of little present value in 

the correlation of well records.

FRONTIER FORMATION

The Frontier formation consists of dark-gray to black shale, about 

625 feet thick, overlain by about 100 feet of beds consisting chiefly 

of sandstone with some interbedded shale, that are locally called Wall 

Creek sandstone. This sandstone makes a prominent hogback ridge 

that trends parallel to the Cloverly hogback and is separated from 

it by a broad valley, which is eroded in the intervening less resistant 

shale. (See pi. 2, B.) In the Salt Creek oil field the Wall Creek 

sandstone is the chief source of oil, and it is also oil-bearing in the 

Lost Soldier district, but within the area here described the sandstone 

that is doubtfully correlated with the Wall Creek has so far yielded 

only minor quantities of oil.

A fossil collection from the Wall Creek (?) sandstone member in 

the SW. % sec. 10, T. 23 N., K. 79 E. (lot 9358), included the following Colorado fauna:

Ostrea sp.

Inoceramus fragilis Hall and Meek. 

Callista tenuis Hall and Meek(?). 

Gyrodes conradi Meek(?). 

Prionocyclus wyomingensis Meek.

CARLILE SHALE

The Carlile shale consists of about 460 feet of very dark shale 

containing some thin sandy layers and many large concretions. It 

usually crops out in areas of low relief and is consequently nowhere 

well exposed.

NIOBRARA FORMATION

The Xiobrara formation consists 'of about TOO feet of dark and 

buff calcareous shale which in places contains some thin layers of 

sandstone. In this particular region the Niobrara contains three 

chalky beds of variable thickness which crop out as conspicuous 

light-colored ridges standing above subdued areas of soft dark shale. 

The upper part and to some extent also the lower part of the formation are characterized by thin layers of white crystalline calcite 

which occurs parallel to the bedding planes. This calcite and the 

color of the formation constitute its most marked lithologic features.
STRATIGRAPHY 17

It contains large numbers of Ostrea congesta, many of which occur 

attached to the shells of large Inoeeramus similar to Inoceramus defoivrvis Meek. These are its most characteristic fossils.

STEELE SHALE

The Steele shale consists of dark-gray shale with some interbedded 

sandstone and sandy shales The most conspicuous sandstone beds 

occur near the top of the formation and in places form conspicuous 

ridges that are difficult to distinguish from similar ridges in the 

Mesaverde formation. (See pi. 3, B.} The shale contains calcareous 

concretions Avhich, in its upper part, are somewhat arenaceous, but 

lower in the formation they consist of a more or less pure limestone. 

In some places on the weathered outcrop of the formation considerable quantities of white crystalline calcite occur in heaps, which 

seem to have resulted from, the disintegration of concretions, though 

no concretions of this material were observed intact. The thickness 

of the Steele is estimated to be 4,000 to 5,000 feet (see pi. 26) but 

can not be accurately determined because of poor exposures.

The contact between the Steele and Mesaverde is gradational, and 

the sandstones mentioned above (see pi. 3, B) have, in some places, 

been included by previous writers in the Mesaverde, whereas in other 

places where they are less conspicuous they have been included in 

the Steele. The writers include in the Steele all sandstones that are 

overlain by thick beds of shale or sandy shale containing a marine 

fauna. It has been found that these sandstones beneath the marine 

shales are variable and can not be recognized everywhere, whereas 

the thick marine sandstones above the highest marine shale form a 

more definite mappable unit, and were included in the Mesaverde 

formation. By this method the Steele is made to include beds of 

marine origin only, and the Mesaverde to include beds of both freshwater and marine origin, the marine beds consisting of heavy sandstones occurring in the lower part of the formation.

Because of its nonresistant character the Steele shale produces 

areas of low relief. It occupies the crest of the Fort Steele anticline 

in the southwest corner of the Walcott quadrangle, where it is 

inclosed by high ridges of the Mesaverde formation. (See pi. 3, B.}

For purposes of description the Mesaverde formation in this area 

may be divided into three members. The lower member is about 

700 feet thick near Fort Steele and consists of indurated white to 

gray massive to thin-bedded and cross-bedded sandstone alternating 

with thinner beds of shale. This member is of marine origin, as
18 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

indicated by the prescence in it of numerous impressions of the 

marine plant Hahpnwnites major and of the marine shells Inocera/inus 

pertenwis, Callista sp., Ostrea sp., Anorfda cf. A gryphorhyncTius. 

Placunoysis hilliarclensis, Solenf sp., Cardiwn speciasum, Pyropsis 

sp.?, and Serpula sp., indicating a Pierre fauna.

The lower member is separated from the middle member by a 

narrow but very pronounced strike valley in which transition beds 

occur. The middle member consists of gray to brown sandstone 

alternating with beds of gray carbonaceous shale and thin irregular 

beds of coal. (See pi. 3, A.) The sandstones range from thin-bedded 

and somewhat flaggy to massive varieties and show more or less crossbedding. On the weathered surface they are prevailingly brown, 

and in weathering they do not give rise to such pronounced vertical 

cliffs and hogbacks as the sandstones of the lower division. The 

coal beds that occur in the member are thin and irregular and in 

many places contain a high percentage of earthy matter. This member contains fresh and brackish water invertebrates, which, together 

with its prevailing brown color and the presence of carbonaceous 

material, serve to distinguish it from the lower member.

The upper member is lithologically similar to the lower member 

in that it consists of white to gray sandstones alternating with beds 

of shale. The sandstone is more resistant to weathering than that 

of the middle division and produces ledges with nearly vertical faces, 

and at the top of the formation there is a prominent white ledgemaking sandstone. In some parts of the field the upper member 

contains thin beds of carbonaceous shale and coal. At other places, 

notably in the railroad cut about 4 miles northeast of Walcott, it 

contains, near the top, numerous Ha&ymenites and Inoceramws remains, which indicate marine conditions.

The aggregate thickness of these three members is about 2,700 

feet near Fort Steele and about 2,200 feet near Alien station, west 

of Medicine Bow The thinning of the formation toward the east 

seems to be at the expense of the lower member, which is not well 

developed in the Saddleback Hills quadrangle.

Because it is more resistant to erosion than the other formations in 

this field, the Mesaverde usually forms the most prominent topographic features. Its distribution is therefore indicated in a general 

way by the distribution of the Ipng, narrow chains of hills A single 

exception to this rule occurs in the outcrop extending diagonally 

across the northeastern part of the Saddleback Hills quadrangle. 

Here the outcrop of the Mesaverde rises but little above the surrounding surface. This approximation of hard and soft rocks to a 

uniform plain, the surface of which is somewhat generally covered 

with terrace gravel, indicates a partial peneplanation in this part 

of the field.
STRATIGRAPHY 19

Ripple marks and cross-bedding are common features throughout 

the Mesaverde. The sandstone beds, which are much more highly 

indurated than in the overlying formations, have been considerably 

fractured and in places even brecciated by the defqrmation to which 

they have been subjected. On Pass Creek, St. Marys, and Cedar 

Ridges, and in the Saddleback Hills, slickensided surfaces are common and are probably due, in part at least, to the slipping of the beds 

on one another in the process of folding.

Section of McsU'Verde formation measured in Rattlesnake Sills, north of Fort

Upper member : Feet

Sandstone, white, with interbedded shale _____ _ 20

Shale, carbonaceous.- _ _ __ __ _________ 3

Sandstone, white ___ _______________ __ __ 8

Talus, probably sandstone ______________ 16

Shale, carbonaceous _________________ _ __ 2

Sandstone, white, granular, ripple marked ____ 33

Talus, chiefly sandstone _________________ 42

Sandstone, white, platy, indurated ________ - 9

Shale, gray. _ __ __ _ ______ _ ___ _ ____ 3

Sandstone, white, platy, indurated _________ ___ 2

Shale ____________________________ 3

Sandstone, white, platy, indurated __________ _ 2

Shale ____________________________ 7

Shale, indurated ______________________ 5

Shale, gray. ______ _ _________ __ ____ 3

Sandstone, white, platy, indurated ______ _ _ 4

Shale ____________________________ 4

Sandstone, thin, indurated ; makes top of ridge _ _ _ 22 

Talus slope ; thin sandstone ledges alternating with

dark shale _______________________ ___ 197

Sandstone, coarse, gray _ _______ __ __ 11

Shale and shaly sandstone _______________ _ 13

Sandstone, thin, brown __________________ 4

Sandstone, white, massive ________________ 13

Shale, carbonaceous at top _______________ 4

Sandstone, white, coarse _______________ 4

Shale, drab _______________ ' __________ 22 

Sandstone, grayish brown, alternating with thin beds

of shale __________________________ 39

Shale, gray _ _ ____________ _ _____ 6

Sandstone, white, coarse. _ _ __________ _ 11

Shale, sandy, and sandstone, gray __________ 45

Sandstone, gray, platy ______ __ ________ 7

Shale and sandstone, alternating __________ _ 56 

Shale, brown, ferruginous _______________ __ _

Shale and sandstone, alternating ____________ _ 28

Sandstone, white, platy ___________ _ ____ 2

Shale, sandy __ __ __ _ ___ i ___________ 9

Sandstone, brown, concretionary, bedded ______ 11

Shale, black ___________ .. ________ : ___ 4
20 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

Upper member Continued. Feet

Sandstone, brown, slabby________________ 10

Shale and thin beds of sandstone___________ 25

Sandstone, brown, thin bedded_______________ 7

Shale, gray ______________________ 8

Sandstone, white, shaly at base_________,___ 18

Sandstone, massive, concretionary, ferruginous___ 10

Sandstone and shale, brown and white alternating__ 100

Sandstone, brown, shaly__________________ 10

Sandstone, white, massive; weathers pockety_____ 8

887

Middle member:

Shale, with thin sandstone beds, partly covered___ 43

Sandstone, brown, coarse________________ 16

Shale, with thin sandstone layers____________ 53

Sandstone, shaly at top, gray to brown________ 19 

Sandstone, brown, thiu, and shale, drab, alternating in

about equal proportion_______________ 35

Shale, buff to gray___ ________________ 15

Sandstone, cross-bedded ___________________ 32

Shale, gray__________________________ 10

Sandstone, gray, cross-bedded______________ 5

Sandstone, grayish brown, thin bedded, slabby____ 65

Shale, sandy_________________________ 42

Sandstone, gray, thin bedded _ __ __ 8

Shale _____________________________ 25 

Sandstone, weathers brown, fresh grayish brown, tine

grained ________ _ _ 2

Shale, gray, sandy_______________ ____ 25

Sandstone, brown, ferruginous __ __ 1

Shale, gray___ __ 10

Sandstone, brown, fine grained_____________ 14

Shale, gray________________ 19

Sandstone, brown, thin bedded, ripple marked _ 5

Shale, gray._ 9

Sandstone, brown, thin bedded _ 8

Shale, carbonaceous_______ _ - 2

Shale __ ._________________________ 9

Sandstone, brown__________ 4

Shale, sandy_________________________ 23

Sandstone, thin bedded- _ 17

Talus slope (sandstone, shalyV)__ _ 34

Shale, sandy__ __ 130

Sandstone, thin bedded __ 2

Shale, sandy, partly covered- _ 78

760

Lower member (marine) :

Sandstone, gray, thin bedded- 93 

Sandstone, thin bedded, white 19 

Sandstone, grayish white, massive; contains Halytnenites major_________________ - 25
STRATIGRAPHY , 21

Lower member (marine) Continued. Feet 

Talus (shale?)______________________ 28 

Sandstone, grayish white, massive____________ 17 

Sandstone, gray, thin bedded___..___________ 75 

Sandstone, gray, heavy bedded_____________ 22 

Shale __________________________ 115 

Sandstone__________________________ 10 

Talus (probably shale or shaly sandstone)___ 42 

Sandstone, grayish brown, thin bedded at base, massive above ______ ____________ 74

Talus (shale?)_______________________ 75 

Sandstone, gray, with thin beds of shale at base. 15 

Sandstone, grayish brown, very shaly, cross-bedded,

thin bedded________________________ 12 

Sandstone, grayish brown, thin bedded______ 10

Steele shale. 

632

Total thickness of Mesaverde__________ 2, 279

LEWIS SHALE

The Lewis shale consists for the most part of dark-gray marine 

shale with numerous intercalated beds of sandy shale and sandstone of variable thicknesses. Prominent sandstones near the base 

of the formation are exposed in the west side of Pass Creek Ridge 

and in the gap between that ridge and St. Marys Hill. The most 

persistent sandstone is 250 feet thick and occurs 600 feet below the 

top of the formation, forming a prominent hogback ridge in places 

more than 100 feet high and separated by a broad valley from the 

basal sandstones in the Medicine Bow formation. (See pi. 4, A.) 

The sandstones are prevailing gray, ripple marked and cross-bedded, 

and in some places very massive. The shale is dark gray and contains a few fossiliferous concretions. The formation is as a rule 

poorly exposed because it occupies areas of low relief and is commonly covered with detrital matter or overlapped by the North Park 

formation. All data obtained suggest that it is about 3,300 feet 

thick in this area.

The Lewis as defined herein includes all of the typical dark-gray 

marine shale lying above the conspicuous white sandstone at the 

top of the Mesaverde formation and below a group of massive brown 

sandstones arbitrarily selected as the base of the Medicine Bow formation.

The fauna of the Lewis in this area is of late Montana age and is 

similar to the Bearpaw shale fauna of Montana. Sphenodiscus lenticidaris (Owen) and a gastropod doubtfully referred to Cominella, 

characteristic Fox Hills species, were collected near the top of the 

formation in the NW. 14 sec. 18, T. 21 N., R. 80 W.
22 « HANNA AND CABBON BASINS, CABBON COUNTY, WYO. 

LATE UPPER CRETACEOUS AND TERTIARY (?) ROCKS 

GENERAL FEATURES

All the Upper Cretaceous rocks in this area from the Thermopolis 

shale to the Lewis shale, inclusive, are marine except a part of the 

Mesaverde formation. In the first 400 or 500 feet above the Lewis 

shale there are a few marine beds with invertebrate fossils of Fox 

Hills types intercalated in the basal part of the succession of late 

Cretaceous and early Tertiary continental deposits, which has the 

enormous total thickness of about 20,000 feet. These intercalated 

marine Cretaceous beds with some associated brackish-water deposits are important in that they show that the change from marine to land and fresh-water conditions was gradual and that no 

great time hiatus is represented between the marine and continental 

deposits. "*

In his reconnaissance work in the Hanna and Carbon Basins 

Veatch u recognized the conformable relations between the Lewis 

and the overlying coal-bearing formation, which he called "Lower 

Laramie," and placed the most pronounced break in the entire 

section between the " Lower Laramie" and the overlying rocks, 

which he called " Upper Laramie." The rocks referred to the Fort 

Union in Veatch's section and placed above the "Upper Laramie" 

have proved to be a part of the "Upper Laramie" and probably some 

distance below its top.

The more detailed work of Bowen 15 has shown that the great 

unconformity which Veatch believed to be at the base of his " Upper 

Laramie " is really in the middle of that aggregate. It therefore 

became necessary to recognize two formations within the " Upper 

Laramie," and inasmuch as the various kind^ of fossils obtained 

from them and from the " Lower Laramie." as interpreted, gave 

somewhat discordant indications of age and correlation, so that the 

correlations suggested by Bowen could not be fully established, it was 

decided to give new local names to the three formations, as follows:

The Medicine Bow formation is essentially the same as the " Lower 

Laramie," though its upper boundary is a few hundred feet lower 

than the boundary between " Lower Laramie " and " Upper Laramie " as mapped by Veatch in part of the area. The Ferris formation is the loAver half of the " Upper Laramie " and is characterized 

in its lower 1,000 feet by conglomeratic beds whose pebbles are only 

of the most resistant kinds of rock, apparently derived from some

14 Veatch, A. C., Coal iu "east-central Carbon County, Wyo.: U. S. Geol. Survey Bull. 

316, pp. 244-260, 1907 ; On the origin and definition of the geologic term " Laramie": 

Jour. Geology, vol. 15, pp. 526-548; Am. Jour. Sci., 4th ser., vol. 24, pp. 18-22, 1907.

15 Bowen, C. F., Stratigraphy of the Hanna Basin, Wyo.: U. S. Geol. Survey Prof. 

Paper 108, pp. 227-235, 1918.
STRATIGRAPHY 23

distant source rather than from the near-by mountains, and without 

recognized fragments of the underlying Cretaceous formation. There 

is no evidence of an unconformity at its base other than the presence 

of irregularly conglomeratic beds. The upper half of the " Upper 

.Laramie " was named the Hanna formation. It rests unconformably

 on the Ferris formation and is lithologically very different from the 

.Ferris in that it is highly feldspathic and its conglomerate contains 

sin abundance of local material, notably granite, Mowry shale, and 

<Cloverly conglomerate. On account of the overlap of the Hanna 

:formation in part of the area the conglomerate at its base was not 

recognized in the earlier work as distinct from the one at the base

 of the Ferris formation.

When these continental deposits of the Hanna Basin are compared 

on the one hand with the Lance Creek section 1C in eastern Wyoming, 

150 miles to the northeast, and on the other with the section of the

 eastern part of the Kock Springs field,17 100 miles to the west, the 

following correlations are suggested by the stratigraphic succession 

.-and by balancing the paleontologic evidence:

The Fox Hills sandstone of eastern Wyoming is almost certainly

 represented in the uppermost part of the Lewis shale, in the lower

500 feet of the Medicine Bow formation, and in the basal member of

the Black Buttes coal group of the Rock Springs field, to the west.

The Lance formation is apparently represented in the major part

 of the Medicine Bow formation, in the lower 1,000 feet of the Ferris 

formation, and in the major part of the Black Buttes coal group.

The fossil plants seem to indicate that the equivalent of the Laramie 

formation of the Denver Basin is also present in the Medicine Bow

 formation, but if distinct from the representative of the Lance formation the boundary between them has not been recognized. The 

JFort Union formation is probably represented by all of the Ferris 

formation except the conglomeratic 1,000 feet at the base. The 

'Hanna formation probably represents the Black Rock coal group,

 of Wasatch age, of the Rock Springs field.

The formal descriptions of the three local formations follow.

MEDICINE BOW FORMATION

The Medicine Bow formation ranges from 4,000 to 6,200 feet in 

thickness and consists of yellow, gray, and carbonaceous shale, beds 

of coal, and gray and brown sandstone. (See pi. 4, B.} The lower

10 Stanton, T. W., and Knowltoii,, F. H., Stratigraphy and paleontology of the Laramie 

and related formations in Wyoming: Geol. Soc. America Bull., vol. 8, pp. 128-137, 1897. 

Stanton, T. W., Fox Hills sandstone and Lance formation (" Ceratopa beds") in South 

Dakota, North Dakota, and eastern Wyoming: Am. Jour. Scl., 4th ser., vol. 30, pp. 

184-187, 1910.

17 Schultz, A. R., The southern part of the Rock Springs coal field, Sweetwater County, 

Wyo. : U. S. Geol. Survey Bull. 381, pp. 222-237, 1910.
24 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

part of the formation is made up of massive to cross-bedded brownt 

sandstones, which usually form a conspicuous group of ledges and! 

contain numerous beds of coal. These sandstones are overlain by an; 

intermediate group of dark-colored shales and thin-bedded finegrained brown sandstones, with some beds of massive white sandstone. The sandstones at the top of the formation are coarse, massive,, 

friable, and easily eroded and are interbedded with thick beds of: 

dark-gray shale.

The area occupied by the formation is usually characterized by 

numerous shallow parallel valleys separated by low sandstone ridges 

surmounted by numerous jutting crags and ledges of indurated brown 

sandstones. As a rule the formation is not well exposed in this area, 

but at its type locality, near the mouth of Medicine Bow River, in 

T. 24 N., R. 84 W., alf details of it are laid bare.

A fresh-water invertebrate fauna with occasional brackish-water 

elements occurs throughout the formation except in the lower part, 

where there are sandstone beds with a marine fauna of Fox Hills 

type. Leaves and bones also occur but are not abundant or, as a rule, 

well preserved. The fresh-water invertebrates are considered by 

Stanton to belong to the Lance fauna, and the plants are regarded 

by Knowlton as belonging to the flora of the Laramie formation of 

the Denver Basin. The bones are chiefly of dinosaurs and include 

some recognized as ceratopsian, though not well enough preserved to 

permit even generic identification.

TERTIARY (P) AND TERTIARY ROCKS 

FERRIS FORMATION

The lower 300 feet of the Ferris formation consists of dark shale 

and coarse, friable massive buff to yellow sandstone containing small 

scattered pebbles and irregular thin beds of conglomerate. Overlying this lithologic unit is one about 800 feet thick, made up largely 

of conglomerate, which occurs as pockets, lenses, and thin beds irregularly distributed throughout the sandstone that constitutes the remainder of the unit. The pebbles of the conglomerate are usually 

less than 1 inch in diameter, are well rounded, and consist of quartzite, black, gray, and yellow chert, jasper, rhyolite, and porphyry. 

The remaining 5,400 feet of the formation consists of gray, brown, 

and yellow sandstones interstratified with numerous thick beds of 

coal.

The sandstones in the Ferris formation are very irregular and 

lenticular, coarse sandstone wedging out between beds of shale and 

vice versa within short distances along the strike. Ripple marks 

and cross-bedding are also features of these deposits. In short, all
STRATIGBAPHY 25

the evidence at hand indicates the rapid accumulation of these beds 

by shifting streams under subaerial or near-shore subaqueous condi^ 

tioris. 

The fossils in the Ferris consist of leaves, fresh-water shells, and 

bones of vertebrates, but the leaves are by far the most abundant. 

Bones occur chiefly in the lower 1,000 feet of the formation and represent turtles, fishes, and dinosaurs. Several of the bone specimens 

have been identified as ceratopsian, and one or two as Triceratops, 

thus apparently correlating the lower portion of the formation with 

part of the Lance formation of Wyoming and Montana, unless perchance they have been derived by erosion from the underlying Medicine Bow formation, as is possible but not probable, because no idenr 

tifiable ceratopsian remains have been found in the Medicine Bow. 

The leaves and shells are regarded as Fort Union types.

HANNA FORMATION

The Hanna formation occupies the central portion of the Hanna 

and Carbon Basins and contains most of the coal mines opened by' 

the Union Pacific Coal Co. in this area. It rests unconformably on 

the Ferris formation and transgresses across all underlying formations at} least down to the Cloverly and possibly down to the granite. 

(See pis. 6, B\ 7, A.) It consists of alternating conglomerate, sandstone, shale, and coal beds, and its base is marked by a thick conglomeratic sandstone and locally by massive conglomerate. (See pis. 

6,4; 7,5.)

The sandstones of the formation range from coarse-grained massive 

or thick-bedded varieties to fine-grained thin-bedded sandstones 

which on weathering assume a brown color and show a tendency to 

split into thin, slabby masses. The coarse-grained varieties are buff or. 

grayish white and commonly more or less conglomeratic. They are 

also highly feldspathic. The pebbles of the conglomerate include, besides materials of the same kind as those that occur in the conglomerate at the base of the Ferris formation^ an abundance of granitic 

material arid locally large quantities of Mowry shale,, Cloverly conglomerate, and soft, sugary sandstone fragments that may have been, 

derived from the Tensleep, Cloverly, or Mesaverde formations.

The Hanna fprmation is about 7,000 feet thick in this area and 

Contains an abundance of plant remains, all of which are referred tx> 

the Fort Union by F. H. Knowlton. The few invertebrates collected 

are also regarded by T. W. Stanton as chiefly suggestive of Fort 

Union age, though species found near the top are said to resemble the 

Wasatch fauna. 'The few fragmentary remains of vertebrates thus, 

far found in the formation include fish scales, fragments of turtle 

shells, and a fragmentary mammalian jaw identified by J. W. Gidley
26 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

as a creodont, probably Claenodon, which may belong to either the 

Fort Union or the Wasatch.

Rippje marks, cross-bedding, and lenticular bedding are charf 

acteristic features of the formation.

NORTH PARK FORMATION

The North Park formation overlies unconformably the Hanna and 

older formations and consists chiefly of fine white unconsolidated 

sand, sandy clay, and marl, which are well described by their popular 

name "mortar beds." * (See pi. 7, C.) In some places a well-defined conglomerate occurs at the base of this formation; in others the 

white sand and clay rest directly on the Hanna formation or older 

rocks. Thin beds of gray .limestone are interstratified with the 

sand and clay, but these limestone beds seem to be of local occurrence. In some localities the attitude of the strata in this deposit 

is in general accord with that of the underlying beds. In other 

places these younger beds dip at angles up to 30° or more in directions almost at right angles to those of older and directly adjacent 

formations.

This formation, according to Veatch,18 attains a maximum thickness of 4,500 feet, but in this area its thickness is believed not to 

exceed a few hundred feet. So far no fossils have been found in the 

North Park formation, but to judge from its stratigraphic relations 

and physicajl character it is almost certainly of middle or late Tertiary age. It is tentatively classified as Miocene(?).

The North Park is separated from the older formations by an 

unconformity as shown by the fact that it overlaps underlying 

formations of Cretaceous and Tertiary age exposed in the field. It 

occurs chiefly in the valleys eroded in the Lewis and Steele shales 

'but also overlaps other formations in areas of low relief.

QUATERNARY DEPOSITS 

TERRACE GRAVEL

<3

Terrace gravel, containing well-rounded pebbles from all the 

underlying rocks down to the pre-Cambrian, covers considerableareas along the present valley of North Platte River and also in the 

eastern part of the Saddleback Hills quadrangle. The gravel beds 

occur at altitudes up to 350 or 400 feet above the present level of 

North Platte and Medicine Bow Rivers, and in some places they overlie the North Park formation and are therefore obviously more recent 

than that formation. They are assumed to be of Quaternary age, 

though there is no direct proof that they may not be somewhat older.

18 Veatch, A. C., Coal fields of east-central Carbon County, Wyo.: U. S. Geol. Survey 

. 316, p. 246, 1907.
U. S. GEOLOGICAL SURVEY BULLETIN 804 PLATE 1

A. TENSLEEP SANDSTONE IN THE FLAT TOP ANTICLINE, SE. % SEC. 12, T. 23 N.,

R. 79 W.

Jl. UPPER PART OF THE CIIUGWATER FORMATION ON LITTLE MEDICINE 

BOW RIVER, SE. % SEC. 13, T. 23 N., R. 79 W.
U. S. GEOLOGICAL SURVEY BULLETIN 804 PLATE 2

A. SUNDANCE, MORHISON, AND CLOVEK1A 1-'uHM/VTlUiNS 1M THE WEST FACE OF COMO RIDGE 5 MILES EAST OF ,\lhijH..i:\h iio\\

Js, Sundanoe; Km, Morrison; Kcv, Cleverly

B. MORRISON, CLOVERLY, AND OVERLYING FORMATIONS ON LITTIj; MK1)ICI\K BOW RIVER, SW. % SEC. 14, T. 23 N., R. 79 W. 

Looking west from Cloverly hogback on Little Medicine Bow.RIver. Km, Morrison formation; Kcv, Cloverly formation; Kt, Thcrmopolis shale; Kms, Mowry shale; Kf, Frontier formation with Wall Creek (P) sandstone member at the top
TJ. S. GEOLOGICAL SURVEY BULLETIN 804 PLATE 3

MESAVERDE FORMATION ON A'OltTH ITATTE RIVER, NW. ]4 SEC. 13, T. 22 \., II. »(> \\.

7?. TRANSITION ZONE FROM STEELE SHALE TO MESAVERDE FORMATION, NW. Vi SEC. 21, T. 22 N., R. 86 W.
U. S. GEOLOGICAL SURVEY BULLETIN 804 PLATE 4

A. SANDSTONE HOGBACK IN THE UPPER PART OF THE LEWIS SHALE, NW. 

, : . SEC. 2, T. 21 N., R. 84 W.

B. MEDICINE BOW FORMATION ON AUSTIN CREEK, SW. Vs. SEC. 12, T. 24 N.,

R. 83 W.
TJ. S. GEOLOGICAL SURVEY BULLETIN 804 PLATE 5

A. UPPER PART OF THE FERRIS FORMATION, NE. K SEC. 31, T. 21 N., R. 83 W.

jf'V'friu^

£. VERTICAL BEDS IN THE LOWER PART OF THE FERRIS FORMATION, SEC. 18,

T. 24 N., R. 82 W.
U. S. GEOLOGICAL SURVEY BULLETIN 804 PLATE 6

K.J- v ^ »i."*>»««»- * - -\ ,J* '.£*- - «fc 'TP- ^ ESP

g^&»^^g^^^:S:J»

^. CONGLOMERATIC SANDSTONE AT BASE OK HANNA FORMATION, NEAR CARBON

B. HANNA J'ORMATION (Th) OVERLAPPING MESA VERDE SANDSTONE (Kmv) AND STEELE SHALE, SE. Ji SEC. 4, T. 23 N., R. 80 W.
STRUCTURE 27 

ALLUVIUM

Along the valleys of North Platte and Medjcine Bow Rivers 

and some of the larger "ditches" there are deposits of alluvial 

material, derived from the older formations, some of which afford 

the sites for the ranches and farms which have been established wherever small level tracts can be irrigated with river water.

STRUCTURE

GENERAL FEATURES

The dominant structural features of the Hanna Basin region are 

the Hanna Basin proper and the subsidiary Walcott and Carbon 

Basins. The partial isolation of the Walcott and Carbon Basins is 

due to the existence of sharp plunging anticlines projecting northwestward and northward from the Medicine Bow Mountain uplift 

on the south.

Faults, or breaks in the surface beds, are much in evidence in 

certain parts of the area, though most of the visible faults are of 

small displacement. Two of them, one on the southwest side of 

St. Marys Ridge, and the other on the northeast side of Cedar Ridge, 

respectively designated for convenience the St. Marys and Cedar 

Ridge faults, are of greater magnitude, and a buried fault of profound displacement is believed to limit the Hanna Basin on the 

north and form the boundary between the basin and the Shirley 

Mountains. The general line of this fault is marked by a zone of 

faults in the Hanna formation, though the downthrow of these 

faults is toward the mountains, suggesting a recent reversal of the 

movements that caused the Hanna Basin depression.

FOLDS

FORT STEELE ANTICLINE

The Fort Steele anticline, named from the near-by town of Fort 

Steele, is the southeastward extension of the Rawlins uplift and 

crosses the southwest corner of the Walcott quadrangle. The anticline is a rather symmetrical fold which plunges toward the southeast. In that direction it rapidly narrows and loses much of its significance, probably not far beyond the southern margin of the Walcott quadrangle, though it is there covered by the North Park formation. The Mesaverde formation, which forms conspicuous rims on 

the opposite limbs of the fold, dips away from the axis at angles 

" of 30° to 50°.

6175^-29 3
HANNA AND CARBON BASINS, CARBON COUNTY, WTO. 

WALCOTT SYNCLINE

Walcott'.syncline, named from the town of,.Walcott, is\the 

^structural, trough separating ..the Fort Steele anjbicline f rom the Cedar 

.Ridge, St. Marys, and Pass Creek Ridge.anticlines, to the northeast. 

-Thie axis of this, syncline: enters the, Walc.otl'quadrangle near the 

northwest corner of .sec.. 28, T. 22 N., R. 85 W,,:and. plunges .southeastward, passing just east of the old Buckley & Ryan mine and 

disappearing beneath the-overlapping North Park formation near 

the southeast corner of the Walcott quadrangle. Throughout most 

of the course in the area mapped the beds forming the northeast 

limb of the Walcott syncline are overturned from the northeast, 

locally with the result that both limbs of. the fold dip in the. same 

direction near its axis, though the beds of ..the northeast limb are 

much more steeply inclined than those of the southwest limb. Northwestward from the Buckley & Ryan mine, however, the overturn 

gradually decreases and the syncline becomes an asymmetric fold 

with steep dips on its northeast limb and more gentle dips (35°) on 

its southwest limb.

CEDAR RIDGE, ST. MARYS, AND PASS CREEK RIDGE ANTICLINES

The general position of the Cedar Ridge, St. Marys,, and Pass 

Creek Ridge anticlines are indicated by the ridges of the same names, 

which extend chain-fashion southeastward from T. 22 N., R. 85. W., 

to T. 21 N., R. 82 W. According to the interpretation of the structure of these features shown in structure sections E-F and G-H, 

Plate 27, they are complexly faulted, first by thrusting, and then by 

subsidence, and it is believed to be probable that the principal upfold 

in the Cloverly beds lies deeply buried northeast of the surface ridges, 

rather than beneath them. At its northwest end the Cedar Ridge 

anticline is a broad, slightly asymmetric open fold, whose axis lies 

at about the crest of the ridge and rises to the southeast. The east 

limb of the fold is cut obliquely by the Cedar Ridge fault, which, on 

passing southeastward from North .Platte River, gradually cuts 

across the axis of the anticline, leaving only the western limb exposed. The strata are slightly overturned in some places, as at the 

southeast end of the ridge, and at other places they are closely compressed and wrinkled into minor folds and broken by numerous 

minor faults.

In the St. Marys anticline the beds are in many places considerably overturned on the southwest limb, except at the extreme ends 

of the anticline. This overturning is doubtless due, in part at least, 

to the drag effects of differential movement along the thrust fault 

that borders the southwestern edge of the ridge. ^Toward' the northwest end of the anticline, where the overturning and faulting gradually give way to normal folding, individual beds can be traced for
'STRUCTURE 29

several hundred feet along their outcrop, and in that distance their 

attitude changes southeastward along the strike from steep, normal 

. southwestward dips to vertical and then to slightly overturned 

positions.

At the southeast end of St. Marys Ridge the northeast flank of the 

anticline has been cut off by faulting, and it appears that this same 

faulting continues northwestward along the northeast edge of the 

ridge, for in this direction the resistant Mesaverde sandstones, which 

should compose the northeast flank of the anticline, are absent for 

nearly 3 miles and are replaced by a low area covered by the nearly 

flat-lying North Park formation. As shown by the geologic map and 

structure section along line E-F, Plate 27, a high-angle fault is believed 'to border the northeast side of St. Marys Ridge. This fault 

may represent a southeastward extension of the Cedar Ridge fault or 

may merely have resulted from stresses similar to those which provided that fault.

The dips are moderate near the west end of the Pass Creek Ridge 

anticline and become progressively steeper near the southeast end. 

Some overturning of the folded beds is visible both southwest of the 

anticline in T. 21 N., R. 83 W., and probably more markedly along 

the north limb of the anticline in T. 21 N., R. 82 W., though exposures are poor in this locality, and the observed dips may be due 

to obscured faulting rather than to overturned folding.

SADDLEBACK HILLS ANTICLINE AND CARBON BASIN

The Saddleback Hills anticline is a long, narrow uplift in T. 21 

N., R. 80 W.,.its position being marked by the conspicuous topo- 

. graphic feature of the Saddleback Hills or Simpson Ridge, formed 

by heavy sandstones of the Mesaverde formation cropping out along 

the anticlinal axis. The dips on the flanks of the anticline for the 

most part range from 25° to 60°, though the east flank of the anticline is somewhat overturned north of the fault that cuts across 

the crest of the fold near the north line of sec. 16. The zones of 

maximum dip along the flanks of the fold occur about 1 mile from the 

anticlinal axis. West of the anticline steeply dipping Lewis and 

Medicine Bow strata are locally concealed beneath the gently dipping 

Hanna formation, whereas on the east side tilted beds of the Hanna 

formation partly overlap the Lewis and flatten eastward toward the 

center of the Carbon Basin, rising gradually thence eastward toward 

the Medicine Bow anticline.

FLAT TOP ANTICLINE

The western part of the Flat Top anticline extends into the northeastern part of the Saddleback Hills quadrangle, causing the expo-
30 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

sures of the Chugwater formation near the eastern margin of the 

quadrangle and of the Tensleep sandstone, half a mile farther east. 

In contrast with folds previously described, the Flat Top anticline 

trends about due east. It is a markedly asymmetric fold with relatively steeper dips on its north flank than on the south, as is shown by 

cross section O-P, Plate 27.

FAULTS

Two major faults or fault systems are developed in the Hanna 

Basin, and numerous normal faults of moderate displacement cut the 

coal-bearing rocks of the area. One of the major faults separates late 

Cretaceous beds from Archean granite in T. 24 N., K. 82 W., and 

presumably continues beneath the cover of the Hanna formation to 

connect with faults in the southwestern part of T. 24 N., R. 80 W., 

and with the fault that lies just south of the crest of the Oil Springs 

anticline in T. 23 N., K. 79 W. The vertical displacement of the 

crystalline basement rocks on this fault is believed to reach a maximum of 30,000 feet, or about 6 miles. The dropping of the area 

southwest of this fault formed the Hanna Basin, and erosion of the 

uplifted region northeast of the fault yielded much of the material 

of which the coal-bearing formations within the basin are composed.

The second major fault series includes the group of faults that 

parallel to St. Marys and Cedar Kidges and may be a part of a continuous fault system including the Arlington thrust fault, which 

bounds the Medicine Bow Eange on its northeast side. The Cedar 

Eidge fault is the westernmost fracture belonging, to this series 

and forms the northeast limit of the Cedar Ridge anticline. This 

fault may be continuous with the fault that bounds St. Marys 

Ridge on the northeast, or more probably with the St. Marys fault, 

which follows the southwest base of St. Marys Ridge and continues thence southeastward as a fault or strongly overturned fold 

that follows the Lewis-Medicine Bow line of contact southwest of 

Pass Creek Ridge and perhaps extends as far as the north flank 

of Elk Mountain, in T. 20 N., R. 81 W.

ST. MARYS FATJI/T

The St. Marys fault follows the southwest base of St. Marys 

Ridge, and along it the Mesaverde formation .has been thrust over 

the Lewis shale (see cross section E-F, pi. 27) and locajly rests 

upon the Medicine Bow formation. The plane of the fault is nowhere clearly exposed, and the presence of the fault is indicated 

solely by stratigraphic relations and by the slickensided surfaces 

commonly displayed by the Mesaverde rocks that form St. Marys
ECONOMIC GEOLOGY 31

Ridge. The fault plane appears to dip gently northeastward, and 

the horizontal movement upon it may attain a maximum of over 

half a mile. The fault can be traced with reasonable certainty for 

about 5 miles and may merge laterally into sharp folds or may .be 

directly continuous with the Cedar Ridge fault and with a possible 

fault following the zone of overturning that marks the LewisMedicine Bow contact southwest of Pass Creek Ridge.

CEDAR RIDGE FAULT

The Cedar Ridge fault follows the northeast base of Cedar Ridge, 

and its plane is exposed in a small gully in the NW. %, sec. 15, T. 22 

N., R. 85 W., where it is nearly vertical and strikes N. 58° W. The 

fault conform^ to the definition of a normal fault, as its hanging 

wall has dropped with respect to its footwall. The amount of the 

displacement, however, is undetermined, although it is at least 500 

feet in the NW. 14 sec. 25, T. 22 N., R. 85 W., and may amount to 

much more than that. At the southeast end of Cedar Ridge the 

fault seems to curve southward and pass between Cedar and St. 

Marys Ridges, distinct evidence of faulting being observable in this1 

gap. No trace of the fault was observed south of the gap, however, 

and it may die out southward or, more probably, connect with the 

St. Marys fault along the southwest base of St. Marys Ridge.

MINOR FAULTS

Numerous small faults of more or less local extent and of relatively 

small displacement occur at several places in the field but most notably in the Rattlesnake Hills, in the northeast corner of the Walcott 

quadrangle, near Hanna, and in the vicinity of Carbon. These faults 

are all believed to be of the normal type in the sense that the hade 

is toward the hanging wall. It is believed, however, that in many of 

the faults the principal movement has been horizontal rather than 

vertical. This belief is based on the fact that in several places there 

is a well-marked horizontal drag along the fault zone.

ECONOMIC GEOLOGY 

COAL

GENERAL OCCURRENCE

The coal in the Hanna and Carbon Basins occurs in the Mesaverde, Medicine Bow, Ferris, and Hanna formations, and the relative

position of the several coal beds within these formations is shown in

Plates 8 and 10. There are at least 4 coal beds in the Mesaverde

- formation which are more than 3 feet thick, 15 in the Medicine Bow
32 HANNA AND CARBON BASINS, CARBON COUNTY, WTO.

formation, 20 in the Ferris formation, and 30 in the Hanna formation, besides numerous lenses of coal that could not be traced because 

of poor exposures.

The coal beds in the Mesaverde formation are principally of low 

bituminous rank and attain a maximum observed thickness of about 

'8 feet in T. 24 N., E. 84 W., near the north rim of the Hanna Basin, 

though elsewhere they are thin and irregular in extent. Most of 

the Mesaverde coal is very impure, the impurities occurring as partings in the bed or intimately mixed with the coal.

The coal beds in the Medicine Bow formation are also thin and 

irregular but not so much as those in the Mesaverde formation. In 

many places the Medicine Bow coal is fairly pure and can no doubt 

be utilized for fuel, though no large mines have yet been opened 

on Medicine Bow coals in this area. The coal of the Medicine 

Bow formation is not uniformly distributed either horizontally or 

vertically. It occurs in a 1,500-foot zone in the lower part of the 

formation. In some places, as in T. 23 N., R. 85 W., this zone contains a dozen or more beds; in other places, as north of Pass Creek 

Ridge and south of St. Marys Hill, only a few beds are present; 

and in still other places no coal of economic importance is known 

to occur within the coal-bearing zone. The coal beds are 11 feet or 

less in thickness, and are very irregular in extent. There seems to 

be no systematic increase or decrease in thickness in any direction. 

The^e coals, though of subbituminous rank, are probably of more 

value than the coals in the Mesaverde formation, but because of 

the presence of thicker and more persistent coal beds in the overlying formations the Medicine Bow coal has thus far been little 

developed in this area.

Both the Ferris and Hanna formations contain numerous beds 

of subbituminous coal which range from a few inches to 25 feet 

or more in thickness and are more extensive and regular in thickness 

than those in either the Mesaverde or the Medicine Bow formations. 

The coal that is being mined at Hanna by the Union Pacific Coal 

Co. occurs in the Hanna formation and is extensively used by the 

Union Pacific Railroad as well as for domestic purposes. The old 

Dana mine, west of Hanna, and the Ho. 5 mine, at Carbon, were 

opened on coal beds within the Ferris formation, but at the present 

time there are no working mines on the coal^ in that formation.

The coal of the Mesaverde formation is black, shows a tendency 

to prismatic jointing or cleavage, and does not break up into flakes 

parallel to the bedding planes on weathering. Because of lack :of 

development of Mesaverde coals in this area only one strictly fresh 

sample was obtained at the Wissler mine, in sec. 22, T. 22 N., R;
. .: ECONOMIC GEOLOGY ....... 33

79 W. This particular coal bed occurs near the top of the Mesaverde 

formation, and its analysis-indicates that it is of subbituminous rank, 

though heretofore Mesaverde coals in this area have been considered 

of bituminous rank. Analyses of samples collected by Veatch 19 in 

1906 show that the Mesaverde coal in this general area after air dry-, 

ing averages about:6 per-cent in mQisturej-the^sh ranges from 2 to.6 

per cent, averaging about 3.5 per cent, and the heating value averages 

slightly more than 12,000 British thermal units.

The coals in the Medicine Bow, Ferris, and Hanna formations are 

of subbituminous rank, are black and shiny, contain a rather high 

percentage of moisture, and disintegrate rapidly when exposed to the 

air. With the loss of their moisture they check and break along 

irregular lines and finally crumble to powder or to thin laminae.

Two samples of coals from the Medicine Bow formation show after 

air-drying average moisture, 8.3 per cent; ash, 3.4 per cent; heating 

value, 11,605 British thermal units. Other analyses of coal in the 

Medicine Bow formation are listed by Veatch.20

No opportunity was afforded to the writers to collect fresh samples 

of coal from the Ferris formation, because of lack of development. 

Veatch,21 however, lists three apparently fresh samples taken in sees. 

25 and 36, T. 23 N., R. 84 W., which after air-drying gave average 

moisture, 10.4 per cent; ash, 5.0 per cent; heating value (one sample 

only), 10,881 British thermal units.

Analyses of representative samples of coals from the Hanna formation have been given by Veatch.22 The analyses of two of these 

samples and of others collected by the writers and representatives of 

the Bureau of Mines are shown on pages 35-36. Analyses of fhese 

samples after air-drying show average moisture, 8.5 per cent; ash, 

6.4 per cent; heating value, 11,360 British thermal units.

The figures given above may be considered representative of the 

chemical qualities of the better grades of coal occurring in the several 

coal-bearing formations of the Hanna Basin.

In order to compare the coals of the Hanna and Carbon Basins 

with those of other fields with which they must compete, analyses 

are also given of coals from the Rock Springs and Kemmerer fields, 

farther west in Wyoming, from the Castlegate district, Utah, and 

from the Denver Basin, Colorado.

The analyses are given in four forms, marked A, B, C, and D. 

Analysis A represents the sample as it comes from the mine. This 

form is not well suited for comparison, because of accidental irregularities in the amount of moisture in the coal as it comes from the 

mine. Analysis B represents the sample after it has been dried

19 Veatch, A. C., op. clt., pp. 253-258. 

»Idem, pp. 254-258.

a -1 Tdenn Idem, p. n 255. 9SR

a Idem, pp. 255-258.
34 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

under standardized conditions. Analysis C represents the .constitution of the coal after all of its moisture has been eliminated, and 

analysis D represents its calculated composition after all moisture 

and ash have been theoretically removed. Form A of the analyses 

represents, with fair accuracy, the composition of the coal as it is 

shipped from the mine; forms B, C, and D arc useful for engineering 

calculations of various sorts.
Analyses oj coal samples from the Hanna and Carbon Basins and of repres

[Made by the United States Geological Survey and the Bur

Source

Ryan mine. _ . ... 

Johnson mine..... __ - ...

Do.. ..................

Wilson mine ...............

Hanna No. 1 mine (abandoned).

Formation

Mesaverde.. 

Medicine Bow. 

.....do.... 

Hanna. _ 

..... do.. .

 -do.......... 

.... .do..........

Location

Quarter

NE.... 

NE. 

SW _ . 

NW 

SE .

BE..... 

NW...

Sec.

22 

11 

14 

6 

32 

32 

20

T. N.

22 

24 

21 

20 

21 

21 

22

R.W.

79 

83 

84 

79 

80 

80 

81

Laboratory No.

A-14124 

22972 

93541 

22800 

93486 

A-14123 

3605

Airdrying 

loss

5.5 

7.2 

2.4 

2.7 

3.5 

3.7 

2.2

Form 

of 

analysis

A 

B 

C 

D

A 

B 

C 

D

A 

B 

C 

D

A 

B 

C 

D

A 

B 

C 

D

A 

B 

C 

D

A 

B 

C 

D

Proxima

Moisture

14.1 

9.2

14.1 

7.5

11.4 

9.2

13.3 

10.9

9.5 

6.2

10.9 

7.4

10.1 

8.1

Volatile 

matter

36.5 

38.7 

42.5 

46.8

32.8 

35.3 

38.2 

40.3

33.8 

34.6 

38.1 

39.5

37.9 

38.9 

43.7 

47.5

39.3 

40.7 

43.4 

47.9

37.9 

39.3 

42.5 

44.2

41.0 

41.9 

45.6 

49.5
Analyses of coal samples from the Hanna and Carbon Basins and of representative 

[Made by the United States Geological Survey and the Bure

Source

Hanna No. 4 mine (composite of 3 samples, 1925).

Rock Springs, Wyo. (average of 4 analyses).

Eemmerer, Wyo. (average 

of 4 analyses).

Castlegate, Utah (average 

of 7 analyses).

Denver Basin, Colo. (average of 4 analyses).

Formation

Hanna. __ ... 

.....do..........

Location

Quarter

NW-...

Sec.

19

T. N.

22

R.W.

81

Laboratory No.

3396 

A-13215

18612

6593 

6837 

6841 

6840

AJrdrying 

loss

3.8 

2.5 

3.6 

1.8 

..1.8

14.7

Form 

of 

analysis

A 

B 

C 

D

A 

B 

O 

D

A 

B 

C 

D

A 

B 

C 

D

A

B 

O 

D

A 

B 

C

D

Proxima

Moisture

12.4 

8.9

10.5 

8.1

10.6 

7.2

3.9 

2.2

4.3 

2.7

21.5 

,7.9

Volatile matter

39.8 

41.3 

45.4 

49.2

40.3 

41.4 

45.0 

47.8

35.2 

36.5 

39.4 

41.1

40.1 

40.8 

41.7 

45.0

43.5 

44.1 

45.7 

49.0

31.2 

36.5 

39.7 

42.7
, .../. ECONOMIC GEOLOGY : 37

From a comparison of the analyses in the f orego.ing table it appears 

.that the coals of the Medicine Bow, Ferris, and Hanna formations 

of the Hanna and Carbon Basins are somewhat higher in moisture 

and lower in heating value than the coals of the Rock Springs, 

Kemmerer, and Castlegate districts, whereas they surpass those of 

the Denver Basin in some respects. Such of the Mesaverde coals 

of the Hanna and Carbon Basins as are of a purity equal to those 

of the Medicine Bow, Ferris, and Hanna coals are believed to be 

slightly higher in heating value than those younger coals, but the 

Mesaverde coajs are of little present commercial interest because of 

their relative inaccessibility and irregularity.

Production and transportation costs, as well as the quality of 

competing coals, determine the markets which each can successfully 

enter, and the future demand for Hanna Basin coal and the direction of its movement will be governed by these factors. Presumably, however, its principal markets will lie near the Hanna Basin 

and eastward and southeastward ajong the lines of the Union Pacific 

Railroad.

. - PRODUCTION AND USES

The coal production in Carbon County amounted to 496^104 tons 

in 1926. Practically all of this came from the mines of the Union 

Pacific Coal Co. at Hanna, though small amounts are produced by 

other mines that supply near-by towns and ranches.

About 90 per cent of the coal mined is used by the Union Pacific 

Railroad for raising steam. The coal is light and makes many sparks 

when burned under forced draft but otherwise gives satisfactory 

results in locomotives. The use of the coal for domestic purposes 

is ajmost wholly confined to the towns along the railroad.

QUANTITY OF COAL

Good topographic maps and reliable information on the position, 

(lip, and thickness of the coal beds and overlying strata make it 

possible to estimate with a fair degree of accuracy the amount of 

coal present 3,000 feet or less below the surface in the Hanna and 

Carbon Basins. The area was divided into a number of narrow 

strips running perpendicular to the outcrop, the total thickness of 

coal at the outcrop and the area were obtained for each strip, and 

on the.assumption that an acre-foot contains 1,800 tons of coal the 

tonnage was calculated for each strip. The sum of these amounts 

gives the coal beneath 3,000 feet or less of cover as 4,264,675,000 tons. 

As some beds undoubtedly are not exposed and escaped observation, 

the estimate is not unwarranted,^ high.
38 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

Sufficient data are not yet available concerning the area in which 

the coal lies deeper than 3,000 feet to estimate the quantity, but it 

is probable that at least as much coal is present below that depth 

as there is above it. . .

Total estimated, quantity, by townships, of coal 3,000 feet or less below the 

surface in the Hanna and Carbon Basins

Township

T. 21 N., R. 85 W. ...... ........

T. 22 N., R. 85 W. ..............

T. 23 N., R. 85 W. ..............

T. 21 N.. R. 84 W. ..............

T. 22 N., R. 84 W.. .............

T. 23 N., R. 84 W.. .............

T. 24 N.. R. 84 W. ..............

T. 21 N., R. 83 W. ..............

T. 22 N., R. 83 W. ..............

T. 23 N., R. 83 W. ..............

T. 24 N., R. 83 W. ..............

T. 21 N., R. 82 W.. .............

T. 22 N., R. 82 W. ..............

T. 23 N., R. 82 W. ..............

T. 24 N., R. 82 W.. .............

T. 21 N., R. 81 W.. .............

T. 22 N., R. 81 W. ..............

T. 23 N., R. 81 W. ..............

T. 24 N., R. 81 W. ..............

T. 20 N., R. 80 W. ..............

T. 21 N.. R. 80 W. ..............

T. 22 N., R. 80 W.. .............

T. 23 N., R. 80 W. ..............

T. 24 N., R. 80 W. ..............

T. 20 N., R. 79 W. ..............

T. 21 N.. R. 79 W. ..............

T. 22 N., R. 79 W. ..............

Mesaverde 

formation

200,000

500,000

4, 158, 000

1,000,000

2, 160, 000

31, 000, 000

6,500,000

8, 200, 000

1, 000, 000

Medicine 

Bow formation

710, 000

15, 600, 000

1,635,000

5,000,000

17,119,000

1,000,000

2,400,000

47, 500, 000

13,420,000

30,000,000

6,000,000

51, 500, 000

200,000

1, 000, 000

4,000,000

Ferris formation

33, 800, 000

313,000,000

8, 023, 000

527,000,000

385, 000, 000

90, 400, 000

13, 000, 000

468, 000, 000

93,300,000

8,700,000

Hanna formation

7,000,000

95, 000, 000

4, 150, 000

529,732,000

19,250,000

20,000,000

222,000,000

12,000,000

287,000,000

700,000

8, 500, 000

101,000,000

Total

200,000

710,000

15,606,000

2,135.000

38,800,000

313,000,000

29, 300, 000

1,000,000

529,400,000

392,000,000

138,900,000

13,000,000

563,000,000

97,450,000

13,420,000

32,160,000

529,400,000

766, 650, 000

19, 250, 000

20, 000, 000

259,000,000

78,700,000

287,200,000

700,000

8, 500, 000

110,200,000

5,000,000

4,264,675.000

TOWNSHIP DESCRIPTIONS

GENERAL SCOPE

In the following township descriptions particular emphasis is 

laid on the location and character of the coal beds, though the topography and geology are mentioned in a general way. The outcrops 

of the coal beds are shown on Plate 27, and the localities at which 

coal sections were measured are marked on the map by numbers. 

The coal sections, correspondingly numbered, are shown in the illustrations or given in the text. In general the coal beds numbered 1 to 

89 are numbered consecutively from the lowest to the highest. (See 

pi. 8.) The coal beds numbered 90 to 130 are undoubtedly equivalent 

to some of the lower numbered coal beds, but as they occur in isolated 

localities no precise correlations could be made. The townships are 

described in order from south to north and west to east, starting in 

the southwest corner of the Walcott quadrangle.
ECONOMIC GEOLOGY 

T. 21 N., R. 85 W.

39

Rattlesnake Eidge, capped by the resistant sandstones of the 

Mesaverde formation, crosses the northeastern part of T. 21 N'., R. 85 

W-5 and rises about a thousand feet above the valley of North Platte 

River, which follows the southwestern base of the ridge. .Owing to

_____T. 21 N., R. 85W. 

Bed

Ft. in.

EXPLANATION

Coal

Bony 

coal

Carbonaceous 

stale

Sandy

shale

Ft. in. .Ft. in. Ft. in.

I 7 I 6

Sondstono

Lenses

I Ft. in. rJr*:iFt. in. ]Ft. in.

I 10

FIGDRB 2. Sections of coal beds In T. 21 N., R. 85 W.

the influence of the Fort Steele anticline, which crosses the southern 

part of the township (see pi. 27), the Steele shale is exposed over the 

central and southwestern parts, and the Mesaverde beds of Rattlesnake Ridge dip northeastward beneath the Lewis shale, which is the 

surface formation in the northeast corner except in a small part of
40 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

sec. 1, in which the basal beds of the Medicine Bow formation are 

present.

The Mesaverde formation is 2,300 to 2,700 feet thick in this township, and a detailed section of it is given on pages 17-21. The Steele 

shale is between 4,000 and 5,000 feet thick, and some 2,500 to 3,000 

feet of it is exposed within the township along the Fort Steele anticline. This fold plunges toward the southeast, and the average dip 

of its northern limb is about 30° as compared with 50° for its southern 

limb.

The small amount of coal in the township is contained in the 

Mesaverde formation and occurs in thin beds, which are irregular 

in character and extent. Bed 1 crops out in the eastern part of sec. 

13 and is represented in Figure 2 by graphic sections 1 to 3. At locations 2 and 3 bed 1 is 1 foot 5 inches thick, and at each place a small 

pit has been opened. At location 1 bed 1 is 1 foot 8 inches thick and 

another bed 19 feet below it consists of two benches of bony coal, 

each about 1 foot 6 inches thick, separated by 1 foot of carbonaceous 

shale. A coal probably equivalent to bed 1 contains 2 feet of shaly 

coal at location 4, in the SW. ^ sec. 11, and 9 inches of coal at location 5, near by. Coal occurs at this horizon at locations 6 to 8, near 

the southwest corner of sec. 3, with a maximum observed thickness of 

1 foot 8 inches at location 7.

Bed 2 is 50 feet above bed 1 in the eastern part of sec. 13 and has 

a maximum thickness of 1 foot 7 inches at location 10. Smaller 

measurements of bed 2 are shown graphically in Figure 2, by sections 

9,11, and 12. Northwest of location 9 bed 2 is represented by carbonaceous shale and thin streaks of coal.

At location 13, in the NE. !/4 sec. 13, a coal bed 1 foot 10 inches thick 

is exposed in an old prospect. In sec. 11 a coal bed at about the same 

horizon as the one measured at location 13 has a maximum thickness 

of 1 foot 6 inches at locations 14 to 16.

T. 22 N., B. 85 W.

Cedar Ridge, an anticline developed in the resistant sandstones 

of the Mesaverde formation, and its southeastward extension, St. 

Marys Eidge, crosses T. 22 N., R. 85 W., diagonally from southeast to 

northwest and attains a maximum height of about 750 feet above the 

North Platte. The land on both sides of these ridges is an undulating, grass-covered plain which stands 150 to 300 feet above the 

river level and becomes rougher toward the river. On the northeastern limb of the Cedar Ridge anticline the Lewis shale and Medi- 

'cine Bow formations are largely concealed by the overlapping North 

Park formation but where exposed dip 2°-31° NE. On the southwestern limb of the anticline the Mesaverde sandstones dip 250-700
ECONOMIC GEOLOGY 41

SW., into a syncline of Lewis shale lying between Cedar and Rattlesnake Ridges, which crosses the southern boundary of the township. 

The Cedar Ridge fault is exposed a little west of the water tank at 

the Miller ranch, north of North Platte River, and also in a small 

ravine half a mile southeast of the Miller ranch. The fault plane is

T. 22 N., R.85W.

EXPLANATION

Coal

I 3

Bed 18 Be42Q

198,

3 4

213,

Lenses

Ft. in.

Bane

Carbonaceous 

shale

Shale

Sandy 

shale.

10 8

FIGURE 3. Sections of coal beds In T. 22 N., 

R. 85 W.

nearly vertical at these places, and the Lewis formation probably has 

been dropped about 1,650 feet with reference to the Mesaverde sandstones in Cedar Ridge.

The amount of coal in the part of the township mapped is exceedingly small and occurs in the Medicine Bow formation. Some
42 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

thin beds occur in the Mesaverde formation north of North Platte 

Eiver and outside the Walcott quadrangle, but none occur within the 

quadrangle itself.

Bed 9 is the lowest-numbered coal bed exposed in the township and 

contains 1 foot 8 inches of coal at location 146, in the NE. % sec. 3. 

Another coal bed lying just above bed 9 contains 1 foot 3 inches of 

coal at location 153, in the NE. 14 sec. 3, and may be bed 10 of T. 

23 N.,,R. 85 W. Beds 18 and 20, the only other numbered coal beds 

mapped in the township, occur in the northern part of sec 2. Bed 

18 contains about 3 feet of coal at locations 198 and 199, and bed 

20 about 1 foot of bone and shale at location 213.

At location 155 in the SE. 1/4 sec. 3, the lowest of three coal beds is 

1 foot 4 inches thick and may be bed 7 of T. 23 N., K. 85 W. The 

two higher beds at this location are less than 2 feet thick, as shown 

in Figure 3.

Beds of carbonaceous shale and coal crop out at locations 154 

and 156, in the SE. % sec. 3, but the coal in none of these sections 

exceeds 1 foot in thickness, as shown by the corresponding graphic 

sections in Figure 3.

T. 83 N., R. 85 W.

The Lewis and Medicine Bow formations occupy the part of T. 23 

N., R. 85 W., that was mapped, and dip 15°-25° E., as shown by structure section A-B, Plate 27. A series of parallel sandstone ridges and 

shale valleys trending nearly north characterize the outcrop of the 

Medicine Bow formation, whereas the Lewis shale crops out in a 

rather broad, open valley.

There are numerous thin beds of coal in the lower 2,000 feet of the 

Medicine Bow formation in this township, none of which were 

found to contain as much as 3 feet of clean coal. The correlation of 

coal outcrops is rendered difficult because of the variable character 

of the coal beds, the small stratigraphic range between them, and the 

comparatively long horizontal distances between exposures. The correlation shown on the map represents the best judgment of the 

writers after a study of the beds in the field and a careful compilation of all the data procured. It is probable, however, that many 

of the beds are lenticular and may vary considerably in thickness 

between points of sectioning, especially where such points are half 

a mile or more apart. The lines of outcrop of the several beds measured and their observed thicknesses are shown, respectively, by 

Plates 27 and 11.

T. 21 N., a. 84 W.

Rattlesnake Ridge and St. Marys Ridge, two prominent ranges 

made up of the heavy sandstones in the Mesaverde formation, break
U. S. GEOLOGICAL SUKVEY BULLETIN 804 PLATE 7

.',*-,~>*^. ":,' _ -i:*;.'^;-;;

 -VT '- " ''v :-. **:- .

'

-I. PANO.RAMA I N SEC. 9, T. 23 N., R. 80 W. 

Showing steeply dipping Hnana i.ocks striking north toward the Freezeout Hills

! . .

- f*^ , ~ :. -PW^ -*» v . .^- :

_-»*^r '." , ' -. ^' -."-,,+ '':'-^::^^-:^^t

 '' *" ~r-**>,?~ '», *" v"*^",^^, ' ,^L -»': f*6fe*rL * ' "" ^^s' -'* "* J*iX-'-'

" ' " ^^«ir .r * x ''fi* -'T^->'-' ' \'^-.' ' *%,^ . _. - ** ' . . -^ 

--.-. - _ -,*!«* *-. " ' ^»^4.w.- -*L. -.-- *«.«Sr*

«V

,^--:.-.c^

£. COACLOMIORATI': Ii\ LOWKH TART OF HAJNiNA FORMATIU.N, SI-J. U SLC. 0,

T. 21 N., R. 81 W. C. NORTH PARK FORMATION ON NORTH PLATTE RI\j;H BELOW SARATOGA
U. 8. BUM.BTIN 804 PLATE 8

FEET

28,000-

27,500-

27,000- 

26,500 

26,000 -

25,500 

25,000 

24,500 

24,000 

23,500 

23,000- 

22,500

22,000 

21,500-

21,000- 

20,500 

20,000-

19,500 

19,000-

North Park 

formation 

Unconformity

s

Hanna 

formation 

7,000'±

Unconformity

Ferris 

formation . 

6,500'±

- ' T5£5&® -^

 1 T-r .-*-

T^=

gS

^JOTTT.

 «?"i>'ib"*T7'

mS^mm

'." '.« '.<> . 

;O;.-T:«-.O; 

 .'°''." o'.'°

bSs

'*. '.*' . ''?

r-=r-=-

 > >.

'^=^=r

irTffyr

* ' ' ' '.

"^^=

:^^

^. T7.'.~

S^T^lI

j o f ' a 

 .'» o ' o'.'-'o'.'o

a. O'.'fl". o

T . Ill . ^-

^ ^v

 ;v?-:?o

^

S-^

=^=:

S

^r±^=

^

TrHi=r^. "T [~7~-- 

J^U^t^ 

morra-t

 

NOS.OF 

COAL BEDS

89

88 

87

66

85

84 

83

82

Hanna No. 

81

80 

79

78 

77

Hanna No.2

76 

75

74 

73

Hanna No. 5

72

71

70

Brooks . . 

(67, 68, and 69

FEET

18,500 -

18,000-

17,500-

17,000- 

16,500-

16,000- 

15,500-

15,000-

14,500 

14,000 

13,500 

13,000 

12,500 

12,000-

66

65 

64

63

6 land 62 

60

59 

58

57 

56

55 

J54 

53 

52

51 

SO

49

45 

44

11,500 

11,000 

10,500 

10,000 

9,500 

E

Ferris 

formation 

6,500'±

*

Medicine Bow 

formation 

6,206 '

XPLANATI

 -;i-^ 

i-a-Arru

T"T-. T-;

 ' ^ ^'

T". 1*1 r"^l

^^=L

^^

^TTj3^2_

. ' .'I-T

0 . 0 . 0 ' ;0

'o '.«.'« .'»;

'.'».'' ' ( 

» '»' .0.'.

: ' :* -V

 ;-'?5:J

'..o « .».

ti^;^i_'._

r^TTf1

 - 

Sr^^r^I

~~~ ^ 

^5^

=_-=^-

^r-^rr

^-^T^r^T

?^r^-

-: i-T-r .-r-r

=^=7 

SZrriSSC5-I

^^

^^5

E^PE

i^i

TT-.- -

^i

±*±;-i:=

isS

i:^-

^

^

^rri^

^=^1=

. ' 11-

.^ET-0

B.^ 1.^^^

.-r-r . T-T

ON

COAL BEDS FEET

43 

4-2 

41 

40

38 and 39

37 36"

34. 3/JUU

33 

32

31 Probable equivalent

,.rt * coal, beds 121-130 ' 30

29

28 8,500- 

27,

26 

25

24 

8,000- 

23

22(Dana(?) 

Lower Dana (?) 

21

7,500 -

7,000- 

6,500-

6,000 

5^00-

spoo4,500 

4,000-

3,500^ 

3,000 

w

2,500 

2^500 

_

1,500-

il 1,000 

17

16 500- 

13

 13

12 Probable equivalent 

, , coal beds 3, 4 , Buckley 

,Q and Ryan,ll3-I20

0-

.0.0 -o o-<

Medicine Bow

formation 

6,200'

Lewis shale 

3,300'

Mesaverde 

formation 

2,700'

Steele shale 

2,500'+

 

0 0 . 0 0 .

1 - =_-

^%51

-^g

--^-r^r

^3U=^Z

lOf

 

 

 .. 

 

 

&*77^

 ' l__ ^r_'"";T" '.'"

j. i ,A * -

^^

:SS

.... . TT

'i ; ~ri

^^

-T .:^,-.- .-r5^fi

5^^

St^

2££:r=

f=;..^-^=

^

i i 'Sf

 

 

NOS.OF 

COAL BEDS

9 

8

7

6

5

II2-B

2 

1

Sandstone Shale Sandy shale Conglomerate Coal bed

COLUMNAR SECTION OF ROCKS EXPOSED IN THE HANNA AND WALCOTT QUADRANGLES

0175 29. (Face p. 42.)
U. S. GEOLOGICAL SURVEY BULLETIN 804 PLATE 9

A. MESA VERDE FORMATION IN SADDLEBACK HlLLS ANTICLINE, SEC. 17, T. 21 N., R. 80 W.

B. OIL SPRINGS ANTICLINE IN SEC. 1, T. 23 N., R. 79 W.

*. ,» *>r ., <«*' .m* -

C. WILSON COAL A1IAE, HE. '^ SIOC. :W, T. 21 N., R. 80 W,
U. 8. GEOLOGICAL 8UEVET BULLETIN 804 PLATE 10

FEET 

26,000 

25500 

25,000-

24,500 

24,000 

23,500 -

23,000 

22,500 

22,000 

21,500 - 

21,000 

20500 - 

20,000 

19,500 

19,000 - 

18,500 -

18,000 - 

17,500 -

Harina 

formation 

7000±

Unconformity

Ferris 

formation 

0 to 2600'

____

- -

- -"-j ' -___. _

\"l ~ T V"M 

== 

'"' ~ . -L

> -0 .0 < 

O.« *O 0

 0*0 o » 

O O O I

NOS.OF 

lOALBEDS FEET 

Alternating beds - 

of coal andcarbonaceous shale -

17,000 

89

88 

16500 

87

16,000 

15500- 

81

QO 15,000 

79

8b 

78 a

14,500 

14,000 

13500-

13,000 - 

12500 

12,000 

1 1,500 - 

III 

no

09 

inal Carbon 

j°8\No46and7

106 

105 '

FINCH

Nos.4and5C?> 

JOHNSON 1Q CQQ _

10,000 -

9500- 

9,000 -

Ferris 

formation 

(continued)

Medicine Bow 

formation 

4000'

Lewis shale 

3000 ±

Mesaverde 

formation 2200*+

 ;:;:/.: :

* rrrrTT".'

*- '!' . ' 

NOS.OF 

OALBEDS FEET .

8500 

-

8000 

7,500 -

7,000 - 

6SOO -

-

6POO - 

5SOO-

«:

4JSOO 

98* -

|g -101 tp 104 

95

- 3SOO 

3,000 

2SOO - 

2,000 -

1500 

1,000 -

94,IOO,andll2a 

93 500 -

92 

91 

0 -

Mesaverde 

formation 

[continued)

Sleele shale 

3600'±

Niobrara 

formation 625'

Carlile shale 460'

Frontier 

formation 725'

Mo wry shale 120'

Thermopolis 

shale 180'

Cleverly 120* form

Morrison 

formation 3507

formation 350'

Chugwater 

formation

f

 -

_..^.._

-=^.T-^irr

-"T-"

i

1

MWMHM^H

NOS.OF 

^)AL BEDS

12

0 and 99

[Wall Creek (?> 

sandstone 

member

EXPLANATION

Sandstone Shale Limestone Sancjy shale Conglomerate Coal bed 

COLUMNAR SECTION OF ROCKS EXPOSED IN THE SADDLEBACK HILLS QUADRANGLE
ECONOMIC GEOLOGY 43

the monotony of the plains in T. 21 N., R. 84 W. Rattlesnake Ridge 

attains an altitude of 7,350 feet, or 875 feet above North Platte River, 

in sec. 18 but decreases in altitude southeastward, owing to the plunge 

of the Fort Steele anticline, and terminates about 1 mile west of Walcott. St. Marys Ridge, which coincides with an anticline by the 

same name, culminates in St. Marys Hill, which rises to an altitude 

of 7,496 feet in sec. 14.

The structure is more varied in this township than in any other in 

the Hanna and Carbon Basins. The Fort Steele anticline crosses the 

southwestern part of the township and is separated from the St. 

Marys anticline by the Walcott syncline, which is occupied by the 

Lewis shale and Medicine Bow formation. The unconformable 

North Park formation covers much of the surface in the vicinity of 

Walcott and north of St. Marys Hill.

Bed 1 occurs about 1,000 feet above the base of the Mesaverde formation and is represented in Plate 12 by graphic sections 17 to 19 

and by the lowest beds in sections 21 and 22. It averages less than 

2 feet in thickness and does not occur east of location 19.

Bed 2 occurs about 50 feet above bed 1 and consists of carbonaceous shale at location 26, in the SE. 14 sec. 20. Elsewhere in the 

township it contains from 9 inches to 2 feet 2 inches of coal, as 

shown by graphic sections 20 to 25 and 27 to 30 in Plate 12.

At locations 31 and 32, in the NW. % sec. 18, a lens of coal, which 

also occurs in T. 21 N., R. 85 W., exhibits a maximum thickness of 

1 foot 9 inches. Another lens contains about 1 foot of coal at location 33, in the NE. % sec. 10. Other Mesaverde coals in the vicinity 

of location 33 are less than a foot thick and were not mapped.

The Buckley & Ryan bed crops out in both limbs of the Walcott 

syncline in the eastern part of the township and has been traced 

from the Buckley & Ryan mine southeastward as far as the railroad. 

At location 39, in the SW. i/4 sec. 14, it contains 6 feet of undivided 

coal. Smaller measurements of it in this township are represented 

graphically in Plate 12 by sections 34 to 38 and 40 to 42, which 

show, from 1 foot to 5 feet of coal. The bed that shows about 2 feet 

of coal at location 43, in the NE. i/4 sec. 24, may be the Buckley & 

Ryan bed, but the correlation is uncertain. At the present time a 

small mine near the old Buckley & Ryan mine yields about 225 tons 

of coal annually for use in Walcott.

Two beds below the Buckley & Ryan bed in the SE. 1/4 sec. 15 

average about 2 feet in thickness, as shown by graphic sections 45 

to 51 in Plate 12 and by sections 300 feet west of location 48, where 

there is 2 feet 4 inches of coal; 90 feet south of location 49, 1 foot 

8 inches; and 100 feet north of location 49, 2 feet at each place 

underlain and overlain by shale.

6175 29 4
44 HANNA AND CARBON BASINS, CABBON COUNTY, WYO.

At location 53, jn the SE. ^4 sec. 24, an old prospect exhibits 4 

feet of coal. At location 52, about 300 feet northwest of the prospect, the coal bed is only 10 inches thick, and 400 feet to the southeast it consists of carbonaceous shale.

Coal beds less-than 3 feet thick occurring in the NW. ^4 sec. 25 are 

represented by graphic sections 54 and 55 in Plate 12. Another 

coal bed 2 feet 7 inches thick crops out at location 56, in the SW.1^ 

sec. 24.

Bed 3 crosses the northeast corner of the township and averages

2 feet 3 inches in thickness at locations 60 to 63, as shown by the 

corresponding graphic sections in Plate 12.

T. 22 N., B. 84 W.

In the southwestern part of T. 22 N., R. 84 W., the North Park 

formation overlaps the Lewis shale and abuts against the Mesaverde formation in St. Marys Ridge, which stands about 400 feet 

above the rolling plain that occupies the remainder of the township. East of the North Park overlap the Medicine Bow and Ferris 

formations dip 25° NE., as shown by structure section E-F, plate 27.

The Mesaverde formation contains one bed of coal near the axis 

of the St. Marys anticline in sec. 31. At location 113 the bed contains

3 feet 7 inches of coal, but at locations 112 and 114 it contains less 

than 2 feet of coal. '

Bed 3 in the Medicine Bow formation crops out in the SW.1/^ 

sec. 36 and is about 2 feet thick at locations 58 and 59. At location 

57 it is only 8 inches thick, and in the two coulees between location 

57 and the wagon road, nearly 1 mile farther to the northwest, no 

coal could be found at its horizon. It is believed, therefore, that 

the bed pinches out a short distance west of location 57.

Bed 4 was traced from the southeast corner of the township northwestward as far as location 90, in tHe NW. % sec. 35, where it is concealed by the surface wash that covers that part of the township. 

Between locations 90 and 100 it contains from 2 to 4 feet of coal, 

but at location 89, in the SE. % sec. 27, not more than 14 inches of 

coaly material was found.

In the SE. 14 sec. 36 a thin bed lying just below bed 4 contains less 

than 2 feet of coal at locations 109 and 110. Farther northwest, at 

locations 107 and 108, a coal bed at about this horizon is slightly 

more than 1 foot thick. Another bed overlying bed 4 in the SE. 14 

sec. 36 contains less than 2 feet of coal at location 104 to 106.

Bed 23, the lowest coal bed in the Ferris formation in this township, is represented in Plate 12 by sections 239 and 240, which show 

a maximum thickness of 2 feet 10 inches of coal. ' Southeast of location 240, in the SE. 14 sec. 2, bed 23 is concealed beneath wash in 

St. Marys Ditch.
ECONOMIC GEOLOGY 45

Except for the section measured at location 247, in the NW. ^ sec. 2, 

which shows only 8 inches of badly weathered coal, bed 24 ranges 

in thickness from 1 foot 1 inch to 1 foot 7 inches in this township, 

as shown by graphic sections 246 to 251 in Plate 12.

Bed 25 is about 200 feet above bed 24 and was traced continuously 

across the northeast corner of the township. Measurements of it mthe township are represented in Plate 12 by sections 259 to 263, which 

show thicknesses ranging between 6 feet 6 inches at location 259, in 

the NW. 1/4 sec. 2, and 11 feet 8 inches at location 263, in the NE. 14 

sec. 12. Usually the bed is broken into several benches by partings, 

.and as a rule the lowest bench contains the best coal.

Bed 25 -is overlain in this township by bed 27, which contains 4 

feet 5 inches of coal at location 291, in the NE. % sec. 2, and 4 feet 4 

inches at location 292, half a mile farther southeast. At location 292 

.bed 25 passes beneath wind-blown deposits occupying a shallow depression, and it could not be traced farther southeast.

Bed 31, which lies about 200 feet above bed 27 in this township, is

 over 12 feet thick at location 348, in the NE. % sec. 2, but could not 

be traced southeastward across the low depression in sec 1. However, as it contains 10 feet of coal in sec. 7 of the township to the

 east, it is probably present beneath this depression and not less than 

10 feet thick.

Bed 33 occurs about 150 feet above bed 31 at location 372, in the 

iNE. % sec. 22, and consists of an upper bed of coal 3 feet 2 inches 

thick separated from a lower bed 8 feet 4 inches thick by about 50 

feet of sandstone and shale. About three-quarters of .a mile north

 of this township these two beds unite to form a single bed of coal 

.about 16 feet thick. However, southeast of location 372 bed 33 evi-

 dently thins out, as it was not found in the township to the east.

T. 23 N., B. 84 W.

North Platte River crosses the southern and eastern parts of T. 

:23 N., K. 84 W., and is bordered by steep bluffs, which rise as much 

.as 200 feet above the flood plain of the river. Away from the river 

the surface is diversified by hills, ridges, and ditches. The most 

prominent ridge is the one that extends northward from the Ferris 

ranch in sec. 23 and rises 475 feet above the North Platte.

The Medicine Bow and Ferris formations occupy the surface of 

the township and have a monoclinal dip of 6°-20° E., as shown by 

:structure section A-B, Plate 27. The monoclinal structure is modified by several normal faults, most of which are probably of small 

magnitude, but oiie designated fault I-I, which dips 70° NE., 

lhas a vertical displacement of about 200 feet and a horizontal displacement of about 900 feet. Faults G-G, H-H, and P-P are downTthrown to the northeast. The vertical displacement is not more than
46 HANNA AND CARBON BASINS, CAKBON COUNTY, WYO.

50 feet, and the horizontal displacement ranges between 0 and 300 

feet. Fault E^-E is downthrown to the west, and fault S-S to the 

east. The block included between these two faults has been shifted 

relatively southward, but the amount of displacement could not be 

determined. It seems that the horizontal offsets on opposite sides of 

the block just about compensate, as the coal bed, measured at location 

678, in the SW. *4 sec. 1, seems to correspond with the one measured 

at location 674, a quarter of a mile farther northeast.

Because the faulted condition of the strata in the northeast corner 

of the township prevents the precise correlation of the coal beds in 

that area with those that occur south of the faulted district, the areas 

will be described separately. All coal beds exposed in the township 

occur in the Ferris formation.

Bed 23 is the lowest coal bed exposed in this township and can 

be traced about a quarter of a mile in the SW. 14 sec. 35 before it disappears in the shifting sands that border North Platte River. At 

location 238 it contains 2 feet 8 inches of coal in two benches separated by 1 foot of shale.

Bed 24 has about the same surface extent as bed 23 and is represented in Plate 13 by graphic section 245, which shows 1 foot 1 inch 

of coal. It was not observed north of location 245.

Bed 25 has a similar distribution to beds 23 and 24 and is represented by graphic sections 256 to 258 in Plate 13, which show a maximum thickness of 4 feet 3 inches of coal.

Bed 27 overlies bed 25 and has been traced by intermittent exposures nearly across the township. Between locations 286, in the 

SE. % sec. 14, and 290, in the NW. ^ sec. 35, its thickness ranges between 4 feet 1 inch and 5 feet, but at location 285, in the NW. % sec. 

14, it is only 9 inches thick. About half a mile farther north, at location 284, it is 10 feet 8 inches thick. From location 283, in the NW. ^ 

sec. 11, bed 27 can be traced northward to location 282, in the SW. ?4 

sec. 2, where an excellent exposure in a small ravine leading down to 

North Platte River shows 6 feet 8 inches of undivided coal underlain 

by 5 feet of bony coal.

Bed 28 has been traced almost continuously from the central part 

of sec. 26 northward to sec. 11, where it passes beneath terrace gravel. 

At location 297, in the NW. a/4 sec. 11, it has a maximum thickness for 

this township of about 18 feet. Other measurements of it in this 

township are shown graphically in Plate 13 by sections 298 to 301.

Bed 31 shows a general though not altogether regular decrease 

in thickness from south to north in this township. At location 347, 

in the SE. y^ sec. 35, it is 19 feet thick and unbroken by partings. 

Another bed about 4 feet below it is 3 feet 5 inches thick and may 

represent bed 29 of T. 22 N., R. 83 W. At location 346, near the 

center of sec. 35, bed 31 is nearly 15 feet thick, and at locations
ECONOMIC GEOLOGY 47

339 to 341, 344, and 345 it is over 10 feet thick. At location 343, in 

the SE. 1/4 sec. 26, an old prospect on this bed shows 6 feet of coal with 

the base not exposed. Another abandoned prospect on this bed was

 found at location 342, in the SE. % sec. 26, but the workings were 

so badly caved that it could not be entered. At location 336, in the 

southern part of sec. 11. bed 31 contains only 1 foot 3 inches of coal.

Bed 32 crops out in sees. 11 and 14 and probably does not extend 

much farther either north or south. At location 363, in the SE. *4 

sec. 14, it contains 2 feet 5 inches of coal split by a 3-inch parting of 

shale. Another coal bed about 30 feet" lower is 4 feet 6 inches thick 

and may be a part of bed 31. Bed 32 could not be traced north of 

location 361, in the, SE. 1,4 sec. 11.

Bed 33 was traced continuously from a point just south of this 

township northward to fault I-I. At location 371, in the SE. % 

sec. 35, it is separated into two benches by a wedge of shale and carbonaceous shale 27 feet thick. The main part of the upper bench is 

5 feet 10 inches thick, and that of the lower bench 7 feet 2 inches 

thick. At location 369, in the NE. *4 sec. 35, bed 33 contains almost 

25 feet of coal, split by three shale partings, each less than 1 foot in 

thickness. Other measurements of bed 33 in the township showing 

from 9 to almost 20 feet of coal are represented in Plate 13 by graphic 

sections 364 to 368 and 370.

At location 671, in the SE. ^4 sec. 11, a coal bed 3 feet 6 inches thick 

occurs a short distance above bed 33, but it could not be traced beyond 

this point.

Bed 35 occurs in the eastern part of sec. 35 and contains less than 

2 feet of coal at locations 380 and 381.

Bed 41 crops out in sees. 13 and 14 and averages 1 foot 9 inches in 

thickness at locations 404 to 407, as shown by the corresponding 

graphic sections in Plate 13.

So far as known, bed 42 occurs only in the NW. }4 sec. 13. It is 3 

feet 8 inches thick at location 408 and 2 feet 5 inches thick at 

location 409.

Bed 42-A overlies bed 42 and has been traced with more or less

 certainty between the north side of sec. 25 and fault I-I in sec. 13. At 

location 410, in the NW. a/4 sec. 13, it contains 1 foot 4 inches of bony 

coal, but it increases in thickness to the south and at location 415, 

in the SW. % sec. 24, contains 3 feet 8 inches of coal in its lower 

bench, and 10 inches in its upper bench, separated by 10 inches of 

shale. Smaller sections of bed 42-A in this township are represented 

in Plate 13 by graphic sections 411 to 414 and 416.

Bed 43 has the same distribution as bed 42-A, which it directly 

overlies, and ranges from 1 foot 6 inches to 2 feet 8 inches in thickness at locations 417 to 423.
48 HANNA AND CARBON" BASINS, CABBON COUNTY, WYO.

Bed 44 has about the same surface distribution as bed 43 and ranges 

in thickness from 11 inches at location 429, in the NW. ^4 sec. 25, to 

6 feet 4 inches at location 431, in the NW. % sec. 36. Other measurements of bed 44 in this township are shown in Plate 13 by graphic 

sections 424 to 428, 430, and 432.

Measurement? of bed 45 in sees. 24 and 25 of this township are 

represented in Plate 13 by graphic sections 433 to 437, which show 

from 1 foot 3 inches to 2 feet 2 inches of coal. A bed tentatively 

correlated with bed 45 contains 1 foot 7 inches of coal at locations 

438 and 439, in the NW. % sec. 36.

Bed 46 is represented south.of fault G-G in sec. 25 by graphic sections 444 and 445, in Plate 13, which show from 2 to 5 feet of impure 

coal. North of the fault it is represented by graphic sections 440 to 

443, which show one or more coal beds from 6 inches to over 5 feet 

thick, interstratified with beds of shale and bony coal.

Bed 47 is a thick bed of carbonaceous shale containing several thin 

beds of coal. At location 447, in the SE. 14 sec. 24, the thickest of 

these coal beds contains 1 foot 6 inches of coal.

Bed 49 overlies bed 47 and attains a maximum thickness for the 

township of 2 feet 3 inches at location 452, near the center of sec. 25. 

Other measurements of bed 49 in this township are represented 

graphically in Plate 13 by sections 451 and 453 to 455.

Bed 50-A occurs in the eastern part of sec. 25 and may be equivalent to bed 50 of T. 22 N., R. 83 W. Its thickest measurement was 

obtained at location 491 and shows 8 feet 6 inches of coal separated 

into two benches by a shale parting 10 inches thick. Smaller measurements of bed 50-A in this township are represented in Plate 13 

by graphic sections 490 and 492. '

Bed 51, which has been traced for several miles in the townships 

southeast of this one, occurs along the eastern border of this township south of Big Ditch. Its maximum thickness of coal for this 

township is 4 feet 6 inches at location 496, in the NE. % sec. 36, and 

its minimum thickness 1 foot 7 inches at location 495, in the NE. ^ 

sec. 25. .

Bed 52 has about the same surface distribution as bed 51 and was 

measured in this township at locations 508 and 509, in the SE. ^4 sec. 

25, where it is 1 foot 1 inch and 2 feet 2 inches thick, respectively.

Measurements of the coal beds exposed in the faulted areas in sees. 

1 and 2 exhibit from 1 foot 2 inches to 7 feet 4 inches of coal, as shown 

by the corresponding graphic sections in Plate 13.

»

T. 84 N., E. 84 W.

In the northeastern part of T. 24 N., K. 84 W., vertical or slightly 

overturned beds in the Mesaverde and Medicine Bow formations
ECONOMIC GEOLOGY . 49

form conspicuous parallel ridges separated by a valley of Lewis 

shale about half a mile wide. The remainder of the township east 

of North Platte River is occupied by the Ferris formation, which 

is unevenly eroded and in places deeply trenched by North Platte 

and Medicine Bow Rivers. In the southeast corner of the township the beds dip about 10° SE.

Bed 112-B, at the top of the Mesaverde formation, .has been 

traced from a point 'about half a mile east of this township westward to North Platte Riveri At location 1475, in the NW. ^4 sec. 2,. 

it contains 15 feet 7 inches of coal separated into three benches by 

partings of shale and sandstone. The thickest bench contains over 

9 feet of coal, as shown by the corresponding graphic section in 

Plate 14. Other measurements showing no individual coal bencE 

over 3 feet thick are represented graphically in Plate 14 by sections 

1474 and 1476 to 1478.

Three beds of coal dip 80° S. in a cut bank on the west side of the 

North Platte in the NW. !/4 sec. 4. The lowest of these beds contains 4 feet of coal at location 1484, the middle one 6 feet of coal at 

location 1485, and the upper one 4 feet of coal at location I486* 

Other lenses in the Mesaverde formation showing from 1 foot & 

inches to 4 feet of coal were measured at locations 1480 and 1482; 

to 1483.

Bed 113, the lowest coal in the Medicine Bow formation in this 

township, ranges in thickness from 1 foot 6 inches at location 1494r 

in the SW. % sec. 3, to 1 foot 10 inches at location 1495, 1 mile 

farther east. At location 1496, in the NEr ^ sec. 12, it contains 2 

feet of carbonaceous shale.

Bed 114 contains about 1 foot of coal at location 1502, in the NE. *4 

sec. 11, and 5 feet of coal at location 1500, in the SW. ^4 sec. 3. Intermediate measurements of it in this township are shown in Plate 14 by 

graphic sections 1501 and 1503.

Measurements of bed 116 in this township are represented in Plate 

14 by graphic sections 1520, 1520a, 1521, and 1521a. Each of these 

sections, except 1521, contains an upper bed of coal about 4 feet 

thick and a lower bed from 1 foot to 1 foot 10 inches thick, separated 

by 4 to 7 feet of shale. At location 1521, however, it contains only 

1 foot 3 inches of coal.

Only two sections were obtained on bed 117 in this township. At 

location 1532, in the NE. % sec. 12, it is made up of two benches of 

coal separated by 20 feet of sandstone and shale. The upper bench 

is 1 foot 6 inches thick, and the lower one 3 feet 4 inches thick, with 

a 2-inch parting below the middle. At location 1531 bed 117 is 

only 8 inches thick.

Measurements of bed 118-A in this township are represented in 

Plate 14 by graphic sections 1542 to 1544, which show about 3 feet of
50 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

coal. At location 1543 a bed of coal 3 feet thick occurs 16 feet below 

bed 188-A.

Sections 1555 to 1557 on bed 119 show a nearly constant thickness 

of about 3 feet 9 inches of coal.

Bed 120, the highest workable coal bed in the Medicine Bow formation in this township, contains an upper bench of coal about 5 

feet thick and a lower bench with a maximum thickness of 2 feet 10 

inches, as shown by graphic sections 1562 to 1564 in Plate 14. At 

location 1562, in the NW. ^ sec. 11, a third bench 2 feet 1 inch thick 

occurs 20 feet below the middle bed.

At location 1569, jn the NE. % sec. 36, bed 121 in the Ferris formation contains about 6 feet of coal separated into three benches by 

beds of shale. Section 1568, between faults R-R and S-S in the 

SW. *4 sec- 36, probably represents this bed and exhibits over 10 feet 

of coal.

Bed 125 contains 7 feet of coal at location 1572, in the NE. 14 sec. 

36, and 4 feet 2 inches of coal, broken by 4 inches of shale, at location 

1571, half a o mile to the southwest. However, at locations intermediate between these points, no coal was found at the horizon of 

this bed.

Sections 1576 and 1577, on bed 126 in the SE. % sec. 36, show about 

3 feet of coal.

At location 1570, in the NW. % sec- 36, a carbonaceous shale bed 

below bed 121 contains 1 foot 3 inches of coal, but beyond that point 

it consists chiefly of shale. Coal beds that probably represent numbered beds in T. 23 N., R. 84 W., crop out in the west bank of the 

North Platte in sec. 35. One of these beds contains 12 feet of coal 

at location 293 and another one 10 feet of coal at location 294. A 

third bed contains 5 feet of coal in a lower bench and about 2 feet 

in an upper bench at locations 295 and 296, the intervening interval 

being made up of shale, bone, and some coal.

T. 21 N., B. 83 W.

Pass Creek Ridge, a prominent anticline developed in the heavy 

sandstones of the Mesaverde formation, crosses the central part of 

T. 21 N., R. 83 W., in a southeasterly direction and rises about 900 

feet above the broken country occupied by the Lewis shale, Medicine 

Bow formation, and North Park formation on each side of the ridge. 

Southwest of the ridge the beds dip as much as 90° into the Walcott 

syncline, the axis of which is covered by the overlapping North Park 

formation, and in some places are slightly overturned. North of the 

ridge the beds dip about 40° NE., as shown by cross section G-H, 

Plate 27.

All coal beds in this township occur in the Medicine Bow formation. At locations 81 to 84, in sec. 36, the lower of two coal beds,
ECONOMIC GEOLOGY 51

which dip about 75° SW., contains about 3 feet of coal, and at locations 85 to 87 the upper one contains from 1 to 3 feet of coal.

Bed 3 was traced from the northwest corner of the township southeastward to the NW. 1/4 sec. 11, where it passes beneath the overlapping North Park formation. Throughout this distance it contains from 5 inches to 3 feet 8 inches of coal, as shown by graphic 

sections 64 to 80 in Plate 12.

Bed 4 lies about 475 feet above bed 3 in this township and is less 

than 2 feet thick at locations 102 and 103, in the NE. *4 sec. 6.

A coal bed 3 feet 5 inches thick crops out at location 88, in the 

NE. 1/4 sec. 6, but could not be traced beyond that point.

T. 82 N., B. 83 W.

In the northeastern part of T. 22 N., K. 83 W., Big Ditch has 

intrenched itself in a valley about 500 feet deep, the north side of 

which is so much dissected by tributary gulches that the descent to 

stream level is very abrupt and in places precipitous. South of Big 

Ditch the land rises gently to the smooth grass-covered divide that 

separates Big Ditch from Walcott Ditch, to the south. The structure in this township is monoclinal, the Medicine Bow, Ferris, and 

Hanna formations dipping to the northeast at an angle which decreases from 40° along the southern boundary of the township to 

about 10° in its northeast corner.

Except for two thin beds of coal in the Medicine Bow formation 

in sec. 31, all the valuable coal in this township occurs in the Ferris 

formation. In general the Ferris coals are thin, but one of them is 

as much as 23 feet thick, and several others are more than 5 feet 

thick.

Bed 4, in the Medicine Bow formation, crosses the extreme southwest corner of sec. 31 and is about 2 feet thick, as shown by graphic 

section 101, Plate 15. At location 111 all but 9 inches of a coal bed 

below bed 4 has been eroded.

Bed 21, the lowest mappable coal bed in the Ferris formation, was 

traced between locations 220, in the SE. y± sec. 17, and 228, in the 

NE. % sec. 26, and shows a rather uniform thickness of about 1 foot 

4 inches of coal except at locations 222 to 224, where it is almost 3 

feet thick.

Bed 22 occurs about 100 feet above bed 21 in sees. 22 and 23 and 

consists of alternating beds of sandstone, shale, and coal with a 

maximum thickness of about 15 feet. No individual coal bed exceeds 3 feet in thickness, as shown by graphic sections 232 to 237, 

Plate 15. A bed which probably represents bed 22 contains about 2 

feet of coal at locations 229 to 231, in sees. 7 and 18.

Bed 23-A occurs in the SE. y^ sec. 23 at about the same horizon as 

bed 23 of T. 22 N., R. 84 W. It contains 1 foot of coal at location 

241 and 1 foot 6 inches of-coal at location 242.
52 HANNA AND CARBON BASIN'S, CAKBON COUNTY, WYO.

Bed 24 was measured in this township only at location 253, in the 

SW. }4 sec. 7, where it contains 1 foot 2 inches of dirty coal.

Bed 24r-A occurs in the southern part of sec. 23 and is probably the 

same as bed 24 of the township to the west. Measurements of itmade at locations 254 and 255 show no single bed of coal over 1 foot 

5 inches in thickness.

Bed 25 was traced from the northwest corner of sec. 17 northwestward into T. 22 N., R. 84 W. Measurements of it at locations 

264 and 265 (see pi. 15) show a maximum thickness of 8 feet of 

coal.

Bed 25-A contains about 12 feet of coal at location 266, in the 

SW. y± sec. 24, and is probably equivalent to bed 25 in sec. 17. 

. Bed 26 was traced less than 2 miles northwestward from the southeast corner of sec. 24 and ranges in thickness from 7 feet 6 inches at 

location 270 in the SW. *4 sec. 24, to 11 feet at location 269 a quarter 

of a mile farther west. (See pi. 15.)

At location 273, in the SW. */4 sec. 7, bed 26-A consists of about 7 

feet of alternating beds of shale and coal.

Bed 28-A occurs about 125 feet above bed 26 and has, been traced 

almost across the township. Except at location 307, in the NW. }4 

sec. 22, where it consists of 2 feet 9 inches of shale and streaks of 

coal, its thickness ranges between 1 foot 3 inches and 4 feet, as 

shown by graphic sections 302 to 306 and 308 to 313, Plate 15.

Bed 29 lies about 50 feet above bed 28-A and appears to be .an 

offshoot of bed 31. In the eastern part of the township these two 

beds are about 250 feet apart, but in the center of sec. 7 the interval 

between them is only 10 feet. At locations 320 and 327, bed 29 is about 

1 foot 6 inches thick, but at locations 317 to 319, in the western 

part of the township, it contains from 5 to 13 feet of coal. Sections 

317 to 319 are shown in Plate 15 under graphic sections 349 to 351 

on bed 31.

Bed 30 crops out hi sees. 23 and 24, where it ranges in thickness 

from less than 2 feet at location 333, in the center of sec. 24, to 

over 7 feet at locations 329 and 330, in the NW. *4 sec. 23. This 

great variation in thickness in less than 2 miles suggests that bed 30, 

like bed 29, is an offshoot from bed 31, and that farther northwest 

they unite to form one thick bed.

Bed 31 contains over 23 feet of coal, separated into four benches 

at location 352, in the SE. % sec. 16. Other sections of the bed 

showing smaller thicknesses of coal are represented graphically in 

Plate 15 by sections 349 to 351 and 353 to 357. At location 349, in 

sec. 7, the lower of two beds of coal, each 5 feet thick, is probably 

equivalent to bed 29, and the upper one probably corresponds to one 

of the lower benches shown in section 350. .
ECONOMIC GEOLOGY 53

Bed 34 was mapped from the southwest corner of sec. 15 southeastward to and beyond the township boundary. Measurements of 

it in this township are represented graphically in Plate 15 by sections 373 to 377, which exhibit a maximum thickness of 2 feet 3 

inches of coal.

Bed 35 was found in this township only at location 382, in the 

NW. y± sec. 7, and contains 2 feet 7 inches of coal separated into 

two benches by partings 1 foot 4 inches thick.

Bed 36 occurs in sees. 15 and 16 and is less than 2 feet thick at 

locations 383 to 386.

Bed 37 lies about 60 feet above bed 36 and is usually too thin and 

dirty to be of any economic value. Measurements of it showing 

a maximum thickness of 7 feet 8 inches of coal are shown graphically 

in Plate 15 by sections 387 to 392.

Bed 38 is 50 feet above bed 37 and contains Jess thai! 4 feet of 

bony coal in this township, as shown by graphic sections 393 to 

399, Plate 15.

Bed 39 occurs in the northern parts of sees. 23 and 24 and contains a maximum thickness of 2 feet 3 inches of coal at locations 

400 to 403.

Bed 40 crops out in sees. 8 and 16 and contains less than 1 foot 

of coal in any unbroken bench.

Bed 48 is 3 feet 5 inches thick at location 448, in the SE. y^ sec. 

14, but contains less than 2 feet of coal at locations 449 and 450, in 

the NW. 1,4 sec. 24.

Bed 49 was traced across the township and usually contains coal 

of good quality. At location 467, in the SW. *4 sec. 14, it exhibits 

3 feet 5 inches of coal unbroken by partings. Smaller measurements 

of it in this township are shown graphically in Plate 15 by sections 

456 to 466 and 468 to 471.

Bed 49-A lies just above bed 49 and at location 475, in the 

NW. 3/4 sec- 6, contains 1 foot 7 inches of coal. A bed at about this 

same horizon contains less than 2 feet of coal at localities 476 and 

477, in the SE. % sec. 8 and the NE. % sec. 16, respectively.

Bed 50 was traced northwestward across the township as far as 

the northwest corner of sec. 8, where it is covered by surface wash. 

Throughout this distance it ranges in thickness from 14 feet 6 inches 

to 3 feet 4 inches and contains numerous partings of shale and bone, 

as shown by graphic sections 478 to 484, Plate 15.

Bed 51 has been traced northwestward from a point near the east 

side of sec. 15 to the north side of sec. 6 and into the township to 

the north. Although it is practically worthless in the eastern portion of the township, it increases in thickness and improves in quality 

toward the northwest, so that at locations 498 to 500, in sees. 6 and
54 HANNA AND. CARBON BASINS, CARBON COUNTY, WYO.

8, it contains about 5 feet of coal, as shown by the corresponding 

graphic sections in Plate 15.

Bed 52 is about 50 feet above bed 51 and has about the same horizontal extent. Like bed 51, it shows an increase in thickness and 

improvement in quality of the coal from southeast to northwest. 

Measurements of it showing thicknesses ranging from 1 foot to 2 feet

5 inches are shown in Plate 15 by graphic sections 511 to 515.

Bed 53 is about 50 feet above bed 52 in sees. 8 and 9 and is so 

badly broken by shale partings that it is of little or no economic 

value. Detailed measurements of this bed are shown graphically in 

Plate 15 by sections 516 to 518.

Bed 54 has about the same distribution as bed 53 and is of little 

value at the east end of its outcrop. At locations 520 to 522, insec. 9, it is badly split by shale partings, which increase in thickness 

to the southeast, as shown by the corresponding graphic sections in 

Plate 15. At location 519; in the SE. *4 sec. 5, it contains 4 feet

6 inches of coal in its lower part, separated by 7 inches of shale from 

11 inches of coal at the top. The bed could not be found northwest 

of this place.

Bed 56-A was traced a little more than a mile in sees. 9 and 10. 

At location 531, in the SW. % sec. 10, it contains 2 feet 11 inches of 

coal, with an 8-inch parting near the middle, but at locations 528 to 

530 it contains less than 2 feet of coal.

Bed 57 occurs only in sees. 13 and 14 and contains about 1 foot 6 

inches of coal, with a thin parting of bone or shale near the middle 

at locations 537 to 540. At location 538, however, it contains 3 feet 

of hard bony coal.

As a rule, bed 58 contains one bench of coal about 3 feet thick 

and several thinner benches separated by partings of shale or bone, 

as shown by graphic sections 549 to 556 in Plate 15.

Bed 59 occurs only in sec. 13 and lies about 40 feet above bed 58. 

At location 562 it contains about 2 feet of shaly coal. At the other 

places it contains about 1 foot 6 inches of coal witii an inch of bony 

material near the bottom. At locations 559 and 560 another bed 

about 4 or 5 feet below bed 59 contains less than 2 feet of coal.

Bed 60-B overlies bed 59 and was traced from the east side of 

sec. 13 to the west side of sec. 11, where it enters the alluvium bordering Big Ditch. In most places where a complete section of the 

bed was obtained it consists of a lower bench made up of alternating 

beds of coal and shale, above which occurs an unbroken bench of 

coal about 2 feet thick. Measurements of the bed are represented on 

Plate 15 by graphic sections 588 to 593.

Bed 61 was traced from the north side of sec. 4 to the southwest 

corner of sec. 3, where.it passes beneath the alluvium of Big Ditch.
ECONOMIC GEOLOGY 55

Its maximum observed thickness in this township is 3 feet 8 inches 

at location 608, in the NW. *4 sec, 4.

Bed 63 is less than 50 feet above bed 61 and has about the same 

horizontal extent. It is about 2 feet thick in this township, as shown 

by sections 628 to 631 in plate 15.

Bed 64 was traced from the north side of sec. 4 nearly to the east 

side of sec. 11 and increases in thickness Irom southeast to north- 

~west. Its thickest bench contains 6 feet 7 inches of coal at location 

f>88 in the SW. 14 sec. 3. Other measurements of the bed in this 

township are shown graphically in Plate 15 by sections 636, 637, and 

639 to 642.

Bed 65 is not exposed in this township southeast of location 649 in 

the SW. 1/4 sec. 3, but in sec. 7 of the township to the east it contains 

12 feet of coal. At location 649 it consists of three benches that have 

a total thickness of 3 feet 11 inches of coal separated by thin partings 

of shale. At location 648 it exhibits an unbroken bed of coal 6 feet 

9 inches thick.

Several disconnected exposures of coal occur above bed 65 in the 

northeast corner of the township. As most of these exposures have' 

not been correlated they are treated as lenses. At locations 801 and 

802, in the NE. 14 sec. 12, a bed of bony coal 1 foot 6 inches thick is

 exposed at approximately the same horizon as that represented in the 

NE. 14 sec. 11 by section 800, which may be correctable, as suggested 

on the map, with the bed represented by sections 797 to 799 in sees.

 2 and 3. This bed nowhere exceeds 2 feet 1 inch in thickness.

Near the north side of sec. 12 a bed of coal 1 foot 1 inch thick is 

exposed at location 803. This same bed is 1 foot 3 inches thick about 

one-eighth of a mile east of this township.

A section measured at location 804, in the NE. ^ sec. 11, shows 11 

inches of coal overlain by alternating beds of coal, bone, and shale.

A coal bed exposed at location 806, in the SE. y^ sec. 2, contains 1 

foot of bony coal. At location 805, about half a mile farther west, 

this bed contains 11 inches of coal and 11 inches of bone and shale with 

.streaks of coal.

In sec. 14 the lower of two thin coal beds is 1 foot 3 inches thick at 

location 811 and 1 foot 6 inches thick at location 812. The upper 

'bed is 1 foot and 1 foot 3 inches thick, respectively, at locations 813 

.and 814.

At locations 815 and 816, in the north-central part of sec. 13, the 

lower of two coal beds above the two beds just described contains 

ubout 2 feet of bony coal in two benches. The upper bed consists 

of alternating layers of coal and shale having an aggregate thickness 

of about 5 feet, of which 2 feet 2 inches is coal.

At location 274-A, in the NE. 14 sec. 25, a bed about 3 feet thick

 crops out. This bed continues eastward but can not be traced west-
56 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

ward. At location 818, in the NE. % sec. 26, another isolated exposure shows 1 foot 6 inches of bony coal;' ; At locations 820, in the 

NW. !/4 sec. 26, and 819, in the SW. % sec. 22, 1 foot 2 inches and 1 

foot 3 inches, respectively, of coal is exposed. At location 821, in 

the western part of sec. 22,1 foot 8 inches of coal crops out.

An isolated exposure of coal in the eastern part of sec. 18 contains 

1 foot 3 inches of bony coal at location 822. Another lens in the 

SW. % sec. 13 contains about 2 feet of coal and bone at locations 

835 and 836.

Bed 67.occurs just above the base of the Hanna formation in 

the northern part of sec. 3 and is represented in Plate 15 by sections 

772 and 773, which show about 2 feet of coal. This bed could not 

be traced east of location 773.

Several lenses of coal occur adjacent to fault U-U in sees. 1 and 2. 

Sections of these beds showing a maximum thickness of 2 feet 6 inches 

of coal are represented in Plate 15 by sections 807 to 810.

T. 23 N., R. 83 W.

The surface of T. 23 N., K. 83 W., is occupied by the Ferris and 

Hanna formations, which, except for the bad lands along Medicine 

Bow River, in the northeast corner of the township, have been 

eroded into a broken and uneven plain. In the southern part of 

the township the beds dip about 10° NE., and in the northern part 

about 10° E. and SE., forming a broad, shallow syncline that 

occupies the area north of Middle Ditch. This simple structure is 

complicated in the western part of the township by many small 

normal faults, which have a general northwest trend and are of 

local extent. In the absence of key beds it was not possible to determine the displacement caused by all the faults or to correlate the 

coal beds on opposite sides of them.

Fault I-I is largely inferred in this township because of the fact 

that no coal beds can be traced across its assumed position, as 

shown on the map. If coal bed 60-A south of the fault is represented north of it by the coal bed sectioned at location 583, in the 

SE. 14 sec. 19, as is believed, the horizontal displacement along 

the fault at this locality is about 1,200 feet, and the beds on the 

north side of the fault have been shifted northwestward relative to 

those on the south side.

Faults J-J, K-K, and L-L are thought to be of small magnitude, 

Faults J-J and K-K are nearly vertical, and the strata on the northeast side have been shifted to the northwest relative to the strata on 

the southwest side. Fault M-M dips 83° NE., and probably has 

caused only a small horizontal displacement of the strata.

Fault N-N dips 84° SW. If coal sections 740 and 749 represent 

the same bed , as is believed, the horizontal displacement along this 

fault is about 2,400 feet.
ECONOMIC GEOLOGY . 57

Fault O-O is nearly vertical, and may be a continuation of faults 

U-U to the southeast and T-T to the northwest.

The Ferris formation contains nearly all t)ie coal .beds exposed, in 

.this township. The coal beds attain a maximum thickness of about 

10 feet, but most of them are thin and lenticular and show a marked 

.decrease in thickness from south to north.

. The coal beds south of fault I-I are. described by numbers, beginning in the southwest corner of the area with the lowest bed, 

and taking each bed up in ascending order. The beds north of 

fault I-I could not be correlated, and the descriptions therefore 

will deal largely with isolated outcrops.

Bed 50-A was measured at locations 489, in the SW. ^ sec. 19, 

and contains two benches of coal about 2 feet thick separated by 

about 2 feet of shale.

Bed 51 is represented in this township at locations 493, in the 

SW. % sec. 19, and 497, in the SW. % sec. 31, which show respectively 2 feet 8 inches and 7 feet 10 inches of coal. The intervening 

sections on this bed are shown in Plate 13.

Bed 52 was measured in this township at locations 504 to 507 and 

510. At all these locations it contains less than 2 feet of coal.

Bed 60-A is represented south of fault I-I at locations 584 to 

587, in sees. 30 and 32, where it has an average thickness of about 

4 feet. North of fault I-I it is probably represented at locations 581 

to 583, where there is also about 4 fe'et of coal.

Bed 61 was traced from the southern boundary of the township 

as far north as fault I-I and is probably the bed found at locations 

598 to 601 north of the fault in the eastern part of sec. 19. Sections 

598 to 607^ Plate 16, show a marked thickening of the bed as traced 

northward, its maximum thickness of 6 feet 3 inches occurring at 

location 604, in the SW. % sec. 29.

Bed 63-A is an offshoot of bed 63, which is split by a shale parting 

8 feet thick at location 625, in the NE. % sec. 32. Bed 63-A is over 

5 feet thick at locations 619 and 620, in the western part of sec. 20, 

and 6 feet thick at location 621, in the NW. % sec. 29. At location 

622, in the SW. ^ sec. 29 it contains two benches of coal, each about 4 

feet thick, separated by 6 feet 2 inches of shale.

Bed 63 was traced from fault I-I southward into T. 22 N., K. 83 

W. At location 626, in the SE. ^ sec. 32, it contains 4 feet 4 inches 

of coal, and at location 625, in the NE. % sec. 32, it is split into two 

beds, the upper of which, bed 63, is 4 feet 3 inches thick, and the 

lower, bed 63-A, is 7 feet 10 inches thick, with a 4-inch parting in 

the lower part. North of location 625 it decreases in thickness and 

contains less than 3 feet of coal at locations 623 and 624, in sec. 29.

Bed 64 ranges in thickness from 5 feet 11 inches at location 634, 

in the NE. *4 sec. 32, to 4 feet 10 inches at location 635, jn the
58 HANNA AND CABBON BASINS, CAKBON COUNTY, WYO.

SW. ^4 sec. 33. In most places, however, it contains a small amount 

of bony coal.

Bed 65 is not well exposed in this township and can be traced 

with reasonable certainty only as far north as fault I-I. Locations 

643 to 645, between faults L-L and M-M, in sees. 20 and 29, are 

probably on this bed. Its maximum thickness for this township is 

about 9 feet at location 647, in the SW. % sec. 33, and its minimum 

thickness 3 feet 5 inches at location 643, in the S,E. % sec. 20.

The lowest coal lens in the township is represented at location 

676, in the NW. y± sec. 6, where there is 2 feet 6 inches of coal. Other 

lenses in sees. 6 and 7 exhibit from 1 to 4 feet of coal at locations 

681, 685, 688, 699, and 700 to 711. Measurements of the coal at 

almost all these locations are shown graphically in Plate 16.

The lowest lens of coal in sec. 18 contains less than 2 feet of bony 

coal at locations 716 to 718. The overlying lens contains no workable coal at locations 714 and 715 but is over 3 feet thick at locations 

712 and 713. Sections 722 and 723 represent two small lenses exposed between faults K-K and M-M in the SE. 14 sec. 18. The maximum amount of coal in any one bench at these locations is less than 

3 feet. Within the same fault block is another lens of coal represented by sections 719 to 721, which show from 2 feet 4 inches to 

about 7 feet of coal. (See pi. 16.)

At location 724, in the southern part of sec. 19, a lens contains 

1 foot 4 inches of coal. Another lens contains 1 foot 2 inches of 

;bony coal at location 725, in the NE. i/4 sec. 19. At location 726, 

in the SW. }4 sec. 30, 4 feet of clean coal crops out south of fault 

H-H, but the bed could not be traced either north or south of this 

location.

At locations 727 to 730, in sec. 8, a lens contains from 1 foot to 2 

feet 3 inches of coal. An overlying lens extends southward into 

sec. 17 and shows a minimum thickness of 1 foot 8 inches of coal 

.and a maximum thickness of 4 feet 5 inches at locations 731 to 735.

The lens of coal represented by sections 736 and 737 in sec. 17 and 

738 in sec. 20 ranges in thickness from 1 foot at location 737 to 4 

 feet 1 inch at location 738. An overlying lens contains 5 feet of 

coal at location 739 and 4 feet 3 inches at location 740. Sections 

exhibiting 1 foot 6 inches were measured on a still higher lens at 

locations 741 and 742.

Sections 743 and 745 represent uncorrelated exposures of coal 

between faults K-K, L-L, and M-M in the western part of sec. 20. 

These sections show from 4 to 5 feet of coal.

North of North Ditch four coal lenses included between faults 

M-M and N-N show a maximum thickness of 4 feet 8 inches of coal 

at locations 746 to 752, as shown by the corresponding graphic sections in Plate 16. South of North Ditch two lenses exposed west of
ECONOMIC GEOLOGY 59

fault K-K in the SW. 14 sec. 20 shows 4 feet and 5 feet 9 inches of 

coal, respectively, at locations 753 and 754. Other lenses exposed 

south of North Ditch in sec. 20 range in thickness from a foot or less 

of bony coal to over 5 feet of coal at locations 755 to 759. (See pi. 

16.) At locations 760 and 761 "only carbonaceous shale is exposed.

At location 762, in the NE.^4 sec. 29, a coal lens contains 2 feet 

8 inches" of coal.

Bed'67, the lowest coal bed in the Hanna formation in this township, is represented by several isolated outcrops which are intersected by faults. Measurements of it made at locations 763 to 771 

and represented graphically in Plate 16 show an average thickness 

of about 3 feet in this township.

Bed 67-A occurs 15 feet above bed 67 and ranges in thickness from 

less than 1 foot to almost 5 feet, as shown by graphic sections 774 

to 778, Plate 16.

Bed 68 is the lowest of two closely associated beds which were 

mapped east of fault 0-0 in the central part of the township. It 

has a minimum thickness of less than 1 foot and a maximum thickness of over 3 feet, as shown by graphic sections 779 to 786, Plate'16.

Bed 69 directly overlies bed 68 and is less than 2 feet thick, as 

shown by graphic sections 787 to 791, Plate 16.

Measurements of lenses in sees. 34 and #5 which show.less than 3 

feet of coal are represented in Plate 16 by graphic sections 792 to 

796.

T. 24 N., E. 88 W.

In the northern part of T. 24 N., R. 83 W., two hogbacks formed 

by the vertical sandstones in the Mesaverde and Medicine Bow 

formations rise several hundred feet above an intervening valley of 

Lewis shale. In the central and southern parts of the township the 

Ferris and Hanna formations dip 5°-20° SE. and have been deeply 

trenched by Medicine Bow River and its tributaries.

Bed 112-B, the only numbered coal bed in the Mesaverde forma 

tion in this township, is represented in Plate 17 by a single section, 

measured at location 1479, in the NE. ^ sec« 6, which shows 6 feet 

of coal. The bed could not be traced east of this locality.

A coal lens just below bed 112-B contains 4 feet of coal at location 

1493 and 5 feet 6 inches at location 1492. A still lower bed contains 

about 4 feet of good coal at location 1491, but is too bony to be of any 

value at locations 1489 and 1490. The lowest bed in the Mesaverde 

contains about 2 feet of coal at locations 1487 and 1488.

Bed 113, the lowest bed in the Medicine Bow formation in this 

township, is not well exposed, as it occurs at the base of the steep 

ridge which marks the base of the formation. Measurements of it

6175 29 5
60 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

made at locations 1497 to 1499 show from 1 foot 8 inches to 3 feet 

5 inches of coal.

Bed 114 is about 150 feet above bed 113. At location 1509, in the 

NE. y^ sec. 11, it contains three benches of coal having thicknesses of 

1 foot 10 inches, 3 feet 8 inches, and 4 feet 6 inches, separated by 

beds of shale and sandstone 5 feet and 3 feet thick. At locations 

1504 to 1508 and 1510 it contains from 10 inches to 3 .feet 10 inches of 

coal.

Bed 115 was not recognized west :of sec. 3. In each of the three 

sections measured at locations 1514 to 1516, in sees. 10, 11, and 12, 

respectively, it is about :2 feet thick, but at location 1514 1 foot 3 

inches of coal occurs 30 feet lower in the section.

Bed 116 is the thickest bed of coal in the Medicine Bow formation in the township and is mined for local use at location 1526, in the 

NE. 14 sec. 11. An analysis of a sample taken from the mine at this 

location is given on page 35. Measurements of bed 116 ma;de at locations 1522 to 1527 and shown graphically in Plate IT exhibit several 

benches of coal separated by partings of shale and sandstone. The 

thickest individual bench contains 6 feet of coal at location 1524, in 

theNE. % sec. 4. ' . , From location 1537, in the SE. ^ sec. 12, westward to location.1535, 

in the NW. y± sec. 11, bed 117 ranges from 5 feet to 7 feet 4 inches in 

thickness, as shown by the corresponding graphic sections in Plate 17. 

At locations 1533 and 1534, in the SE. % sec. 6 and the SW. % sec. 4, 

respectively, it is about 2 feet thick.

Bed 118 contains 1 foot 8 inches of coal at location 1549, in the 

NE. % sec. 11, and 5 feet 2 inches of coal at location 1547, in the 

SW- 1A sec. 4. These and intermediate measurements are shown 

graphically in Plate 17. A bed designated bed 118-A overlies bed 

118 in the SE. 14 sec. 6 and contains 1 foot of coal at location 1545.

Bed 119 crops out between location 1558, in the SW. % sec. 5, and 

location 1561, in the NW. i/4 sec. 11. Measurements made of these and 

intermediate locations exhibit from 1 foot 4 inches to 3 feet 10 inches 

of coal, as shown in Plate 17. '

Bed 120 has about the same distribution as bed 119 and contains 

about 2 feet of coal at locations 1565 to 1567.

At locations 1582 and 1583, in sees. 5 and 7, two beds of coal each 

about 1 foot 6 inches thick are separated by about 22 feet of shale 

and sandstone.

The coals in the Ferris formation in this township are equivalent to 

the lower Ferris coals mapped in T. 23 N., Rs. 83 and 84 W., but it is 

impossible to correlate the beds between the two places. These beds 

are more or less irregular and show a tendency to split up into several benches or be replaced by shale.
ECONOMIC GEOLOGY 61

Bed 122 is the lowest numbered Ferris coal in the township and 

crops out for a distance of about 2 miles in sees. 21 and 29. At locatipn 1585, in the NW. *4 sec. 29, it has a maximum thickness of 17 

. feet 8 inches of coal. Smaller measurements of it are shown graphically in Plate 17. ......

Bed 123 has about the same distribution as bed 122 and likewise 

is concealed bjr terrace gravel east of sec. 21. At location 1590, in'the 

 SW.,14 sec. 29, it contains over 15 feet,of clean coal, and the base of 

the bed is cut off by a small fault.. Smaller measurements of it are 

shown graphically in Plate 17 by sections 1591 to 1596.

Between locations 1603, in the SE. 1/4 sec. 21, and 1608, in the 

NE. % sec. 22, bed 124 is from 2 to 4 feet thick. West of location 

1603, however, it becomes thicker, and at location 1598, in the SE. 14 

sec. 30, it contains about 15 feet of coal. Other sections of this bed 

are shown graphically in Plate 17. ,

Bed 125 is an offshoot from bed 124. between locations 1597 and 

1598, in sees, 31 and 30, respectively. Measurements of it made at 

locations 1573 to 1575 show a maximum thickness of over 8 feet of 

coal.

Bed. 126 crops out in sees. 3.0 and.31 and contains less than 3 feet 

of coal at locations 1578 to 1581.

Bed 127-A apparently represents the upper part of bed 127, with 

which ,it unites in the western part of the township. Sections of it 

given in Plate 17 show a maximum thickness for this township of 

.16 feet of coal at location 1615, in the NW. ^ sec. 28, and a minimum 

thickness of about 1 foot at location 1618, in the SE. % sec. 22.

At location 1612, in the SE. 14 sec. 29, bed 127 contains 3 feet of 

coal, but at points on both sides of this location no coal was found 

at its horizon. A coal bed over 8 feet 6 inches thick at location 1611, 

in the SW. % sec. 29, probably respresents bed 127-A.

So far as known, bed 128 occurs only in sec. 31. Sections of it at 

locations 1619 to 1621 show a maximum thickness of 6 feet of coal.

Bed 129 is thin and bony, as shown by sections 1622 to 1629, Plate 

17, Its maximum thickness of 3 feet 10 inches occurs at location 

1627, in the NE. 1/4 sec. 28.

Bed 130 contains 5 feet 7 inches and 5 feet 6 inches of coal, respectively, at locations 1630 and 1631, in the SE. % sec. 31. A mile 

farther east it consists of carbonaceous shale.

At location 1632, in the NW. % sec. 32, a lens between beds 129 

and 130 contains 8 feet of coal. No coal was found, however, at this 

horizon elsewhere. At location 1633, in the SW. % sec. 31, another 

lens is over 3 feet thick.

A lens between 122 and 123 contains 5 feet 7 inches of coal at location 1635, in the NW. ^ sec. 29, and 10 feet of coal at location 1634.
62 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

A lens below bed 122 in sees. 20 and 29 contains less than 2 feet of 

coal in any individual bench at locations 1636 to 1638. A still lower 

lens contains 3 feet 9 inches of coal at location 1639, in the SE. 14 

sec. 20, and 2 feet of coal broken by a bone parting 6 inches thick at 

location 1640.

At location 1642, in the SE. 14 sec, 20, a bed. of coal 3 feet thick, 

4 inches of which is bone, crops out in tiie east bank of Medicine Bow 

River. At location 1641 a bed somewhat higher in the section, contains 3 feet of coal.

T. 21 N., K. 82 W.

In Pass Creek Ridge, which crosses the southwest corner of T. 21 

N., R. 82 W., the heavy sandstones in the Mesaverde formation dip 

westward beneath the Lewis shale at angles ranging between 30° 

and 70° and are overlapped on the north side of the ridge by the 

North Park formation, which occupies a syncline lying between the 

ridge and the outcrops of the Ferris and Hanna formations along the 

northern boundary of the township. Except for Pass Creek Ridge, 

where a maximum altitude of 7,905 feet is attained, the surface of 

the township is for the most part comparatively level and has an 

altitude ranging between 6,800 and,7,10Q feet.

All the coal in this township occurs in the Ferris formation along 

the northern boundary of the township. The coal beds are poorly 

exposed, and most of the outcrop lines shown on the map have been 

projected from the township to the north. The coal sections measured in this township are exhibited graphically in Plate 18.

The Lower Dana bed occurs about 50 feet below the Dana bed at 

the old Dana mine, in the NE. y± sec. 5. A section of the Dana bed *" 

measured hese, by Veatch in 1906 shows 11 feet 2 inches of coal, 

with a thin parting of shale near the middle. North of this location it becomes thinner and more broken.

The only other coal beds exposed in the township are beds 61-A 

and 65, which show 3 feet and 8 feet 6 inches, respectively, of coal at 

locations 618 and 655, in the northern part of sec. 3. Bed 65, however, 

is split by a shale parting 4 feet 6 inches thick.

1. 22 K.. R. 82 W.

The surface of T. 22 N., R. 82 W., is occupied by the Ferris and 

Hanna formations and is very rugged and broken. In the northwestern part of the township the base of the Hanna formation is marked 

by a conspicuous sandstone escarpment that trends in an east-west 

direction and rises about 600 feet above Big Ditch, which crosses the 

central part of the township. This escarpment veers to the south in 

sec. 10 and becomes inconspicuous in the broken country south of the 

railroad. In the northwestern part of the township the beds dip
ECONOMIC GEOLOGY 63

6°-16° N.; elsewhere they dip 8°-25° E. and NE. .Faulting on a 

small scale has occurred in the northeastern part of the township.

The Lower Dana bed, the lowest coal bed in the Ferris formation, 

occurs at location 277, in the SE. 14 sec. 32, where it contains 3 feet 1 

inch of coal. Farther north, at locations 274 to 276, it averages 

about 2 feet in thickness, as shown by the corresponding graphic sections in Plate 18. This bed has about the same stratigraphic position as bed 21 of T. 22 N., R. 83 W., but it could not be traced between the two places.

The Dana bed at location 281, about half a mile north of the old 

Dana mine, is split by several partings of shale, bone, or dirty coal, 

so that it contains a lower bencji of coal 4 feet 6 inches thick and an 

upper bench 2 feet 10 inches thick. At locations 278 to 280 it is 

much thinner, as shown by the corresponding graphic sections in 

Plate 18.

A bed that is probably-bed 23-A of T. 22 N., R. 83 W., contains 1 

foot 8 inches of coal at location 243, in the NW. *4 sec- 30. At location 244, iy2 miles farther southeast another bed at about this horizon contains 2 feet 6 inches of coal.

Bed 25-A is about 500 feet above the Dana bed and occurs in a 

strike valley filled with wash derived from near-by ridges. Only 

one measurement of the bed was obtained in the township, at location 267, in the SW. !/4 sec. 29, which shows 7 feet of coal.

Bed 26 is about 100 feet above bed 25-A and occurs near the crest 

of the ridge that forms the northeastern boundary of the valley occupied by bed 25-A. Sections of it measured at locations 271 and 272, 

in the SW. % sec. 19 and the SW. !/4 sec. 29, respectively, contain 

between 8 and 9 feet of coal broken by one or two thin partings.

Bed 28-A is represented in this township by sections 314 and 315, 

each, of which contains about .1 foot 6 inches of .coal.

Bed 30 contains 1 foot 7 inches of coal at location 334, in the 

S,W- -^4 sec. 19, but at location 335, half a mile farther east, it 

Consists chiefly of carbonaceous shale.

Bed 31 crops out only in sec. 19, of this township and contains 

from one to three benches of coal, each about 3 feet thick, as shown 

by graphic sections 358 and 359, Plate 18.

Bed 34, like beds 30 and 31, occurs only in sec. 19 and contains 

1 foot 6 inches of coal at location 378. At location 379, less than 

half a mile farther east, it is less than 1 foot thick.

Bed 49, which ranges from 1 foot to 3 feet 5 inches in thickness in 

the township to the west, contains 1 foot 5 inches of coal at locations 472 and 473, in sees. 19 and 20, respectively. At location 474, 

in the NE. *4 sec. 29, it contains chiefly of shale. 

. Bed 50 is a thick bed of coal that is commonly split by numerous 

shale partings and associated with thick beds of carbonaceous shale.
64 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

At location 486, in the NE. ^ sec. 20, it contains 19 feet 6 inches of 

coal separated into three benches by shale partings 2 inches thick. 

Above this, thin layers of coal alternate with beds of shale through 

a vertical distance of 20 feet. Smaller measurements of bed 50 in 

this township are shown graphically in Plate 18 by sections 485, 487, 

and 488. Between location 485 and the western edge of the township, bed 50 is concealed beneath alluvium and gravel in the valley 

of Big Ditch.

Bed 56 occurs about 100 feet above bed 55 and consists of several 

benches of coal split by shale partings. Altogether it contains over 

15 feet of coal at location 535, in the SW. % sec. 21, but is thinner 

elsewhere in the township, as shown by the graphic sections in 

Plate 18.

Bed 57 contains 1 foot 3 inches of coal at location 548, in the NE. 14 

sec. 28. North of this location it increases regularly in thickness 

and becomes almost 4 feet thick at location 542, in the SW. % sec. 18. 

West of location 542 it thins rapidly until at location 541, in the 

SW. % sec. 18, it contains about 1 foot of coal.

Bed 58 has its principal development in the township to the west 

And contains less than 2 feet of coal at locations 557 and 558, in 

the western part of sec. 18.

Bed 59 usually consists of two benches of coal, each about 2 feet 

thick, separated by a shale parting about 1 foot thick; Measurements of the bed in this township are shown graphically in Plate 18 

by sections 563 to 575.

Bed 60 was traced about 3 miles north of Big Ditch. At location 580, in the NE. y^ sec. 21, it contains 3 feet 8 inches of coal^ 

below which are several thinner coal beds alternating with beds of 

shale. Elsewhere in the township it is less than 2 feet thick and 

much split up by partings, as shown by graphic sections 576 to 579, 

Plate 18.

Bed 60-B occurs a short distance above bed 60 and may be equivalent to bed 60-A of areas farther west. Its average thickness in 

this township is about 2 feet, as shown by graphic sections 594 to 

597, Plate 18.

Bed 61-A is about 150 feet above bed 60 and at about the horizon 

of bed 61 of the township to the west. Measurements of it ranging between 1 foot 8 inches and 5 feet are shown graphically in 

Plate 18 by sections 611 to 618.

Bed 65 is commonly concealed in a valley lying between resistant 

beds of sandstone. It is well exposed, however, in the railroad cut 

at location 654, in the NW. % sec. 34, and is about 12 feet thick; the 

lower 5 feet 6 inches is free from partings, and the remainder is split 

by several thin partings. Other measurements of it showing from
ECONOMIC GEOLOGY 65

1 foot 7 inches to 12 feet of coal are shown in Plate 18 by graphic 

sections 650 to 653 and 655.

Bed 66 occurs near the top of the Ferris formation in the central 

part of the township. Measurements of it made at locations 661 to 

670 average about 2 feet in thickness,

A lens just below bed 66 in sees. 15 and 22 contains a maximum 

thickness of 2 feet of coal at locations 656 to 658. Another lens 

showing about 2 feet of coal crops out at locations 659 and 660, in 

the western part of sec. 34.

The Brooks bed is about 175 feet above the base of the Hanna formation and extends northward from location 834, in the NE. ^4 sec; 

27, as far as the fault in sec. 6. Measurements of it in this township, 

represented graphically in Plate 18 by sections 824 to 834, show 

from 3 feet to almost 7 feet of coal.

Bed 70 consists of two coal beds each about 2 feet thick, separated 

by about 7 feet of shale, as shown by graphic sections 837 to 841 in 

Plate 18. ,

Bed 71 lies a short distance below the Hanna No. 5 bed in the 

faulted area in the northeastern part of the township. Sections of it 

measured at locations 842 to 844 show about 2 feet of coal.

Bed 72 immediately overlies bed 71 and is very variable in thickness, as shown by graphic sections 849 to 855, Plate 18. Its maximum 

thickness of 4 feet occurs at location 854, in the SW. % sec. 24.

The Hanna No. 5 bed is the lowest thick bed of coal in the Hanna 

formation and has been extensively prospected by the Union Pacific 

Coal Co. In the faulted area in the northeast corner of the township 

the partings that are present in the bed farther south become thicker 

and give rise to several coal beds. This splitting up of the bed, 

together with the faulted structure, makes it difficult to correlate 

exposures correctly. However' it is certain that the bed deteriorates 

in thickness and quality toward the north and is finally replaced by 

shale and sandstone. At location 878, in the NW. % sec- 25, it 

consists of three benches of coal, the upper of which is 12 feet thick 

and contains only one thin parting. This bench is separated by 5 

feet of shale from the middle bench, which is 7 feet thick. This is 

followed by 3 feet 5 inches of shale, below which is 1 foot 4 inches 

of coal. North of location 878 as far as fault W-W it maintains 

a total thickness of 29 to 34 feet arid is commonly divided into three 

benches, the upper of which is 10 to 14 feet thick and is in some 

places broken by one or more thin partings. At locations 866 and 

867, in sec. 12, 7 feet 4 inches and 5 feet 2 inches, respectively, of 

coal was found, but it seems probable that these sections represent 

only a part of the bed. At location 865 its total thickness is 2 feet, 

but a considerable proportion of this thickness consists of carbonaceous shale, and the thickest bench of coal is 3 feet 3 inches thick.
66 HANNA AND CAKBON BASINS, CARBON COUNTY, WYC.

North of location 865, in the SE. % sec. 1, it is broken into several 

distinct benches.

At locations 879 and 880, in the SW. % sec. 6, a coal lens contains 

about 3 feet of coal. Another lens traced northward from the central'part of sec. 14 contains as much as 2 feet 9 inches of coal at locations 881 to 886. At location 887, in the SW. % sec. 1, a lens which 

may possibly represent bed 70 contains 1 foot 6 inches of coal. At 

location 888, in the SE. 14 sec. 1, four benches of coal are exposed 

which in descending order have thicknesses of 4 feet 2 inches, 2 feet 

2 inches, 1 foot, and 1 foot 6 inches. These benches are separated 

by beds of sandstone and shale ranging from 4 to 10 feet in thickness.

Measurements of a thick carbonaceous shale bed above the Hanna 

No. 5 bed at locations 889 to 893, in this and the adjoining township 

on the east, show from 11 inches to 7 feet of coal, but the thicker coal 

beds are considerably broken by partings.

At location 896, in the SE. *4 sec. 13, two coal beds less tlian 2 feet 

thick are separated by Zy2 feet of shale.

At location 897, in the eastern part of sec. 24, an upper bed of 

coal 1 foot 6 inches thick is separated from a lower bed 1 foot 3 

inches thick by 5 feet 6 inches of shale. These beds may represent 

bed 74, which has been traced northward for several miles but which 

is of no value south of the railroad.

T. 23 N., R. 82 W.

Except for the small amount of alluvium along North and Middle 

Ditches and Medicine Bow River, the surface of T. 23 N., R. 82 W., 

is occupied by the Hanna formation, which dips 6°-12° E. or NE. 

Picturesque badlands characterize a belt about 2 miles wide south of 

the Medicine Bow, and a similar though less marked type of topography occurs in the southeast corner of the township.

The two thick benches of the Hanna No. 5 coal bed mapped in 

townships to the east and south are largely replaced by shale and 

bone in sees. 24 and 25, as shown by graphic sections 856 to 859, 

Plate 19. The thickest bench contains 4 feet of coal at location 859, 

in the SE. 14 sec. 25.

At location 964, in the SE. ^ sec. 12, bed 78 contains almost 11 feet 

of coal split by a shale parting 3 feet thick. At location 962, about a 

mile to the northwest, it exhibits only shale, bone, and conglomerate.

At location 987, in the center of sec. 12, bed 80 contains two benches 

of coal, each about 1 foot thick, separated by 8 inches of shale.

At locations 899 to 903, in sec. 32, a lens contains from 1 to 5 feet 

of coal, as shown by the corresponding graphic sections in Plate 19. 

Another lens contains 2 feet of coal at its top and three benches of 

bony coals below at location 898. in the NE. 14 sec. 24.
ECONOMIC GEOLOGY 67 

T. 24 N.( K. 82 W.

Prominent hogback ridges are formed by highly inclined beds in 

the Mesaverde, Medicine Bow, Ferris, and Hanna (basal part) formations faulted against the rugged granitic masses of the Shirley 

Mountains, in the northern part of T. 24 N., R. 82 W. Between 

the southernmost Hanna hogback and Medicine Bow River the 

Hanna beds flatten out and are eroded into badlands, which become 

more accentuated toward the river. Formations older than the 

Mesaverde crop out east of the great fault in the northeastern part 

of the township, and a conspicuous outlier of the overcapping North 

Park formation occurs in sec. 11.

Coal occurs in this township only in the Medicine Bow formation. 

The coal beds in the Mesaverde formation are represented by beds of 

carbonaceous shale, and those in the Hanna formation by the coarse 

sediments characteristic of the formation along the northern margin 

of the Hanna Basin; the Ferris coals are concealed beneath the 

Hanna overlap.

Bed 114 contains 8 feet of coal at location 1513, in the NW. !/4 sec. 

0, and about 3 feet of coal at locations 1511 arid 1512, in sec. 8. No 

coal was found at its horizon east of location 1513.

Bed 115 contains from 2 to 4 feet of coal at locations 1517 to 1519, 

us shown by the corresponding graphic sections in Plate 19.

Bed 116 is from 5 to 7 feet thick at locations 1528 to 1530, in 

sec. 8. Another coal bed from 2 to 4 feet thick occurs about 30 feet 

below bed 116 at locations 1529 and 1530 and has been mined for local 

use at location 1530.

Bed 117 contains less than 2 feet of coal at locations 1538 to 1541, 

as shown by the corresponding graphic sections in Plate 19.

Bed 118 is 5 feet thick at location 1553, in the SE. 14 sec. 8, but is 

only 8 inches thick at location 1552, in the SW. *4 sec. 8. Good exposures east of location 1554, in the SW. ^4 sec. 9, show no coal at this 

horizon.

The lowest isolated exposure of coal in the township occurs at location 1643, in the SE. % sec. 8, and exhibits about 2 feet of coal. 

Another lens measured at locations 1644 to 1646 has a maximum 

thickness of 3 feet 6 inches of coal. The bed which contains 7 feet of 

coal at locations 1647, in the SW. % sec. 3, may also represent this 

lens.

At locations 1648 to 1650, in sees. 8 and 9, a lens contains from 2 to 

6 feet of coal. At location 1651, in the SE. *4 sec. 8, an upper bed of 

coal over 10 feet thick is separated by 19 feet of sandstone and shale 

from a lower bed 6 feet thick. This abnormally thick section is 

probably a local thickening caused by the squeezing and buckling of 

the strata.
68 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

Sections 1652 and 1653, in sees. 8 and 9, show 3 feet 4 inches and 5 

feet, respectively, of coal in a bed occurring just below bed 114. 

Sections 1655 and 1654, in sees. 7 and 8, are measurements of a bed 

lying between beds 117 and 118 and exhibit about 1 and 5 feet, respectively, of coal.

T. 21 N., R. 81 W.

The north end of the Elk Mountain anticline is outlined by the 

steeply dipping sandstones of the Mesaverde formation in the southern part of T. 21 N., R. 81 W., and rises about 500 feet above the 

surrounding lowlands of Lewis shale. The remainder of the township is occupied by the Medicine Bow, Ferris, Hanna, and North 

Park formations, all of which, except the North Park, occupy areas 

of variable relief and dip 10°-86° NW., toward the center of the 

Hanna Basin.

Bed 94, in the Mesaverde formation, contains 2 feet 6 inches of 

coal at location 1239, in the NE. *4 sec. 36, on the west limb of the 

Saddleback Hills anticline, but was not observed in the Elk Mountain anticline in this township.

Bed 95, in the Medicine Bow formation, averages about 2 feet 4 

inches in thickness at locations 1245 to 1248, as shown by the corresponding graphic sections in Plate 22.

Bed 96 contains three benches of coal less than 1 foot thick at 

location 1252, in the NE. % sec. 13. Sections of this bed farthest 

southwest, at locations 1249 to 1251, show less than 3 feet of coal.

Bed 97 contains 1 foot 7 inches of coal at location 1267, in the 

NE. 34 sec. 13, but at locations 1265 and 1266, in sec. 22, it contains 

about 4 feet of coal.

Bed 98 is from 6 inches to 2 feet thick at locations 1270 and 1271, 

in sec. 13, but was not recognized west of the fault in sees. 13 and 14.

T. 22 N,, R. 81 W.

North of the railroad in T. 22 N., R. 81 W., the Hanna formation 

has been much dissected, and nearly all the larger coulees are bordered by one or more conspicuous sandstone rim rocks. Several hills 

that rise as much as 700 feet above the railroad also characterize this 

part of the township. South of the railroad the surface is much less 

rugged.

The main structural feature in the township is the Hanna syncline, 

which crosses the township in a northeasterly direction and is separated from a larger and more irregular basin to the northeast by a 

slight transverse upwarp along the northern boundary of the township. The Hanna beds on the west limb of the Hanna syncline dip 

eastward at angles which gradually decrease from 23° in the western 

part of the township to horizontality in the center of the depression.
ECONOMIC GEOLOGY

East of the cynclinal axis, however, the beds are sharply upturned to 

about 35° and then gradually diminish in dip to about 12° at the 

eastern margin of the township. Besides being tilted and folded, the 

beds have been displaced by many small faults, and the horizontal 

displacement on opposite sides of some of the faults amounts to 2,000 

feet. The average displacement, however, is not more than a few 

hundred feet and decreases toward the axis of the Hanna syncline. 

The following figures, obtained from the mine superintendent at 

Hanna, represent the displacements observed along faults in the 

mines and prospects of the Union Pacific Coal Co. at Hanna:

Famlt displacements at HunnaFault

W-W 

X-X 

Y-Y 

Z-Z

'

Dip

35° NE. 

67° NE. 

NE. 

82° SW.

Vertical 

separation 

(feet)

174 

157 

100 

100

Horizontal 

separation 

(feet)

170 

125 

103 

100

'

Most of these faults show greater horizontal displacement at the 

outcrop of the coal beds than underground. In addition to the 

faults designated above, numerous other faults of small displacement have been encountered in the mines at Hanna. At the abandoned mining camp of Sampo, in sec. 2, two small faults inclose a 

down-thrown block with but little displacement.

The coal beds exposed in this township occur in the Hanna formation and include beds from No. 72 to the Hanna No. 1 bed. Beds 

exposed farther west are probably within mining depth in the western part of the township. All the Ferris coals are believed to be over 

4,000 feet below the surface of this township.

The Union Pacific Coal Co. has extensively prospected the coal 

beds with the diamond drill in this and adjoining townships, and 

though the data obtained by it have been available to the writers, 

they are considered confidential and are not included in this report.

Bed 72 contains 1 foot 6 inches of coal at location 848, in the 

NW. % sec. 7, but was not measured elsewhere in the township.

The Hanna No. 5 bed crops out in sees. 6 and 7 of this township 

and consists of five benches of coal, distributed through an interval 

of about 30 feet and separated by beds of carbonaceous shale and 

sandstone. Graphic sections of this bed in Plate 20 show that the 

thickest individual bench contains 6 feet of coal at location 864, in 

the NE. % sec. 7. ' - 

Just below the bed sectioned at location 889, in the NW. % sec- ?» 

the lower of two other coal beds contains 1 foot 8 inches of coal 

at location 894 and the upper 7 feet 6 inches of coal at location
70 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

895. These beds may represent a part of the Hanna No. 5 bed, 

but because of faulting and the lack of key rocks this can not be 

demonstrated.

Bed 73 is offset by each of the faults north of fault X-X but 

could not be recognized south of this fault. It ranges from 1 foot 

5 inches to 5 feet in thickness and is either bony or split by several partings of shale, as shown by graphic sections 906 to 910, 

Plate 20.

Bed 74 lies about 80 feet above bed 73 and crops out between fault 

W-W and the northern border of the township. At location 918, 

in the SW. 14 sec. 18, it contains about 18 feet of coal split by four 

partings of shale and sandstone, of which the thickest is 4 feet 

thick. Smaller measurements of bed 74 in this township are represented graphically in Plate 20 by sections 914 to 917.

Bed 75 lies about 150 feet above bed 74 and extends from the northern border of the township southward as far as the small fault just 

south of fault Z-Z. Sections of it measure^ at locations 922 to 924 

and represented graphically in Plate 20 show alternating beds of 

shale and coal distributed through a vertical interval of about 15 

feet, but the only valuable coal occurs at location 922, in the 

NE. 1,4 sec. 5.

Bed 76 occurs about 50 feet above bed 75 and is of value only north 

of Big Ditch. At location 932, in the center of sec. 18, it contains 

eight coal beds distributed through a vertical interval of 35 feet. 

The individual beds range in thickness from 7 inches to over 6 feet. 

Other fairly thick measurements of the bed showing either a greater 

or less amount of coal in individual .benches are shown graphically 

in Plate 20 by sections 928 to 931", 933', and 934.

The Hanna No. 2 bed is the thickest coal bed in the township. Its 

outcrop enters the township near the southwest corner of sec. 19 

and trends northwestward to and beyond the township border in 

the NE. % sec. 5. In the Nos. 2 and 4 mines of the Union Pacific 

Coal Co., in the,* NW. y± sec. 19 and the SW. 14 sec. 18, respectively, 

it is about 35 feet thick and contains several shale partings each about 

1 foot thick. Two miles south of the No. 2 mine it is reported to be 

only 12 feet thick. North of the No. 4 mine its outcrop is usually 

burned, but measurements of part of the bed showing 25 and 30 feet 

of coal, respectively, at locations 959, in the NE. 14 sec. 8, and 960 in 

the NW. 14 sec. 17, suggest that its thickness remains constant as_far 

as the northern boundary of the township.

The outcrop of bed 77 trends northeastward from fault X-X and 

leaves the township near the northwest corner of sec. 3. Sections 

of it measured at locations 944 to 958 and represented graphically 

in Plate 20 show that it has a variable thickness in this township and
ECONOMIC GEOLOGY 71

contains many partings of shale. The thickest individual bench 

contains almost 9 feet of coal at location 948 in the NE. 1/4 sec. 17.

Bed 78 is about 150 feet above bed 77 and has been extensively 

prospected in the vicinity of Hanna by the Union Pacific Coal Co. 

Between locations 968 in the SW. ty sec. 3, and 984 in the {8W- 14 

'sec. 19jvit contains?from 6 to 27^feet of coal, as shown^by the corresponding graphic sections in Plate 20. In many of these sections the 

coal is broken into several benches by partings of bone or shale that 

attain a maximum thickness of 4 feet, but generally one bench of coal 

6 to 10 feet thick is present. Between locations 984a and 986, in 

the southwest corner of the township, bed 78 contains two benches 

of coal about 2 feet thick separated by a bed of shale of about the ' 

same thickness.

Bed 77-A occurs in sees. 10, 11, and 15, in the eastern limb of 

the Hanna syncline, and is approximately equivalent to bed 77, 

which crops out in the western limb of the syncline. It contains one 

bench of coal about 2 feet thick and several thinner ones separated 

by greater thicknesses of shale, as shown by graphic sections 1089 to 

1091, Plate 20.

Bed 78-A is probably the same as bed 78 in the western limb of the 

Marina syncline. South of the railroad, at locations 1004 to 1006, it 

contains about an equal amount of shale and coal distributed through 

an interval of 6 to 21 feet; the thickest individual coal bed is 6 feet 

thick at location 1004, in the NE. % sec. 28. Immediately north of 

the railroad, however, it consists of three beds ranging through an interval of about 170 feet. Still farther northeast these beds merge into 

one thick bench of carbonaceous shale about 40 feet thick, which contains several benches of coal. North of Sampo the bed again splits 

into two members, the outcrops of which are rather widely separated 

because of the smaller dips. The upper^member is designated bed 

78-B and contains 6 feet of coal in four benches separated by thin 

partings of shale and bony coal at location 1024 in the SE. % sec. 2. 

Other measurements showing the characteristics of bed 78-A, as described above, are represented graphically in Plate 20 by sections 

1007 to 1013.

Bed 79-A crops out around the north end of the Hanna syncline 

and is probably equivalent to one of the beds lying between the Hanna 

No. 1 bed and bed 78 at the south end of the syncline. It averages 

about 8 feet in thickness and contains from 2 feet 6 inches to 5 feet 6 

inches of coal broken in most places by one or more partings of shale, 

as shown by graphic sections 1035 to 1040, Plate 20.

Bed 80-A has about the same distribution as Bed 79-A and contains from 3 feet 10 inches to 6 feet 11 inches of undivided coal at lo-
72 HANN,A. AND CABBON BASINS, CARBON COUNTY, WYO.

cations 1053 to 1057, as shown by the corresponding graphic sections 

in Plate 20. ; : . Bed 80-B trends approximately-parallel to Bed 80-A and contains 

about 2 feet of coal, as shown by graphic sections 105B to 1062, 

Plate 20.

Bed 80-C is about 35 feet above bed 80-B and consists of two 

benches of coal about 2 feet thick separated by about 8 feet of shale 

br sandstone. Measurements of this bed are represented graphically 

in Plate 20 by sections 1063 to 1066.

Bed 83-A lies about 160 feet above bed 80-C and just below the 

Hanna No. 1 bed. Measurements of it represented graphically in 

Plate 20 by sections 106? to 1074 show thicknesses ranging between 

1 and 4 feet. .

The Hanna No. i bed was first opened up at the Hanna No. 1 mine, 

in the NW. % sec. 20, and later at Nos. 3 and 3y2 mines, in the SW. % 

sec. 16'and the SE. 14 sec. 17, respectively. It lies about SCO feet 

above bed 78 arid 1,500 feet above the Hanna No. 2 bed and encircles 

the Hanna syncline with but few interruptions. The workings of the 

Nos. 1 and 3 mines have been extended completely across the syncline. 

The bed has an average thickness of about 23 feet and in some places 

is comparatively free from partings but in others is divided into 

many benches by numerous thin partings of shale and bony coal. 

Measurements of the bed in this township are represented in Plate 20 

by graphic sections 1079 to 1084 and 1086 and that at the Hanna No. 1 

mine.

Bed 79 crops out in sees. 2 and 3 and probably corresponds to beds 

79-A and 80-A, which occur 1 mile farther south. At locations 1041 

and 1042, in sec. 2, partial exposures show not less than 5 feet 6 inches 

of undivided coal, but at locations 1039 a and 1040 a, farther northwest, its full thickness of about 34 feet shows at least five coal beds 

separated by fairly thick benches of shale, the thickest individual 

bench of coal being only 5 feet thick.

Numerous disconnected outcrops of coal in this township are 

grouped under the heading of lenses in Plate 20. The lowest of 

these stands vertical in the Ferris formation at location 1109, in the 

NE. 14 sec. 25, and contains two beds of coal, each about 1 foot 

thick, separated by a bed of carbonaceous shale 2 feet 4 inches thick.

Sections 1107 and 1108 are measurements of a lens about 2 feet 

thick lying between beds 77 and 78 in sec. 3. Sections 1103 and 1104 

are on the lower of two beds lying between bed 78 and the Hanna 

No. 1 bed in the southwestern part of the township and show about 

2 feet of coal. Another bed immediately overlying the one just 

described is from 3 to 12 feet thick at locations 1095 to 1099 but 

contains no individual bench of coal over 5 feet thick. Other meas-
ECONOMIC GEOLOGY 73

urements of lenses in the southwestern part of the township, showing 

from 1 to 10 feet of coal are represented graphically in Elate. .20 by 

sections 1101,1102,1105, and 1106. , . - . , :...

A lens which may be -equivalent to the Hanna No. 2 bed contains 

6 feet of coal separated into two .benches by a bed of carbonaceous 

shale 1 foot 6 inches thick at location 1094, in the NE. y^ sec. 15. 

Farther northeast, however, it contains 1 foot or .less of coal. .Another 

lens contains about 2 feet of coal at location 1110, near the center..of 

sec. 17. ' ' - '..-..:.. ".... , .;-..

Sections 889, 891, 894, and 895, in the western part of sec. 7, are 

shown graphically in Plate 18,. for T. 22 N., R. 82 W-, in order 

to show their relations to sections dn the same bed in:that township. 

The coal in these lenses ranges .from about 2 to 8. feet in thickness.

T. 23 N., R. 81 W. , .

The Hanna formation occupies the surface of T. 23 N.,. R. 81 W., 

and dips 15° NE., toward the center of the structural basin in [ the 

northeastern part of the township. Ridges formed by the more 

resistant Hanna beds cross the township in a northwesterly direction in conformity with the strike of the strata, and rise abruptly 

above parallel valleys, which either lead directly into Medicine 

Bow River or into its tributary Willow Spring Draw, a small canyon 

trending northeastward across the township.

The thick coal beds exposed in T. 22 N., R. 81 W., occur also in 

this township, but as a rule they contain too many thick partings to 

be of economic value. The deterioration is caused chiefly by the 

interfingering from the north of sandstone and conglomerate and 

the replacing of the coal beds by thick beds of carbonaceous shale.

Bed 72 crops out in the western part of sec. 31 and contains 

several beds of coal less than 2 feet thick separated by thicker beds 

of shale at locations 846 and 847. Northwest of location 846 it contains no coal.

At locations 860 and 861, in the NW. % sec. 31, the lower bench 

of the Hanna No. 5 bed contains 5 feet of coal and the upper bench 

2 feet 6 inches of coal. A measurement of the upper bench at location 862, in the SW. 14 sec. 31, shows about 3 feet of coal, which is 

bony in the upper part.

Bed 73 is the lowest of four coal beds that underlie the Hanna No. 

2 bed in the southwest corner of the township. At locations 904 and 

905, in the NW. % sec. 29 and the NW. % sec'. 32, respectively, bed 73 

is as much as 13 feet thick, but all the individual benches of coal are 

less than 2 feet 6 inches thick.

Bed 74 lies about 80 feet above bed 73 and contains over 4 feet of 

coal in a lower bench at location 912, in the NW. 14 sec. 32. Measurements at locations 911 and 913 showing smaller amounts of coal
74 HANNA AND CABBON BASINS, CARBON COUNTY, WYO.

are represented graphically in Plate 21. This bed contains no coal 

northwest of location 911.

Bed 75 occurs about 150 feet above bed 74 and contains less than 2 

feet of coal in any individual bench at locations 919 to 921, as shown 

by the corresponding graphic sections in Plate 21.

Bed 76-A is probably equivalent to bed 76 of the township to the 

south, but this can not be proved. , At location; 926, in the northern 

part of sec. 32, it contains four benches of coal from 1 foot 7 inches 

to over 3 feet thick, distributed through a vertical interval of 16 feet. 

At locations 925, in the NW. % sec. 29, and 927, in the SE. % sec. 

32, it contains only a few inches of coal.

Although the Hanna No. 2 bed is about 30 feet thick in the township to the south, it contains no coal in Willow Springs Draw, in the 

NW. y± sec. 29, where excellent exposures occur. Between the draw 

and the southern boundary of the township its outcrop is either concealed in the grass-covered slopes or burned, and no measurements of 

it could be obtained.

Measurements of bed 77 at locations 937 to 943 are represented by 

corresponding graphic sections in Plate 21 and show thicknesses 

ranging between 3 and 28 feet. At all these locations, however, beds 

of shale and bony coal split the bed into benches that contain from 1 

to 11 feet of coal.

Bed 78 is about 150 feet above bed 77 and contains over 15 feet of 

coal at location 966, near the center of sec. 28. At locations 965, in 

the SW. 1/4 sec. 17, and 967, in the NE. % sec. 33, it contains about 10 

feet of coal.

Beds 78-A and 78-B cross the southeast corner of the township 

and are more fully described under T. 23 N., K. 80 W. Bed 78-A was 

not sectioned in this township, but a section of bed 78-B at location 

1025, in the southern part of sec. 36, contains two benches of coal, each 

about 4 feet thick, separated by 3 feet of shale.

Bed 79 in this township is probably the same as beds 79-A and 

80-A of T. 22 N., E. 81 W. At location 1043, in the SW. *4 sec. 36, 

it contains 11 feet of coal, but at all other locations except 1044, where 

it exhibits 8 feet of coal, it consists of several coal beds less than 2 

feet thick separated by beds of shale, as shown by the graphic sections 

in Plate 21.

Bed 80 in this township is probably the equivalent of beds 81-A 

and 82-A of T. 22 N., R. 81 W. Measurements of it made at locations 

988 to 999 and represented graphically in Plate 21, show thicknesses 

of coal ranging between 3 and 11 feet.

Bed 81 appears to have the same stratigraphic position as the 

Hanna No. 1 bed in T. 22 N., R. 81 W., but there is no resemblance 

between the two beds. At locations 1111 to 1119 it exhibits from 1
ECONOMIC GEOLOGY 75

to 5 feet of coal, as shown by the corresponding graphic sections in 

Plate 21.

Bed 82 is a lens about 5 miles long. Sections of it exhibiting from 

about 2 to 5 feet of coal are represented in Plate 21 by graphic sections 1127 to 1132.

Although bed 83 is of considerable thickness in certain portion^ 

of its'outcrop in this township, it nowhere contains an individual 

coal bench as much as 3 feet thick, as shown by graphic sections 1140 

to 1143, Plate 21.

Bed 84 contains from 4 to 6 feet of coal at locations 1150 to 1152, 

near the eastern border of the township, but farther northwest it 

consists of alternating beds of shale, bony coal, sandstone, and coal, 

and the coal is nowhere over 3 feet thick, as shown by graphic sections 1147 to 1149, Plate 21.

Bed 85 has about the same distribution and characteristics as bed 

84. At location 1159, in the SW. % sec. 13, it consists of 30 feet of 

carbonaceous shale interstratified with several beds of coal less than 

1 foot thick. To the northwest, at locations 1153 to 1158, it consists 

of alternating beds of carbonaceous shale and coal distributed 

through a maximum vertical interval of 33 feet and nowhere exhibiting individual benches of coal over 4 feet thick.

Bed 86 is essentially a thick bed of carbonaceous shale and bony 

coal which locally contains beds of coal 1 foot or less in thickness, 

as shown by graphic sections 1162 to 1163 a, Plate 21.

Bed 87 occupies an interval of about 30 feet, of which approximately 50 per cent is coal distributed in beds not over 4 feet thick, 

as shown by graphic sections 1164 to 1166, Plate 21.

As shown by graphic sections 1174 to 1177, Plate 21, bed 88 is a 

thick bed of carbonaceous shale that contains numerous intercalated 

beds of coal, none of which exceed 4 feet in thickness.

Bed 89 is of no economic value in this township, although in the 

township to the east it contains some good coal.

A lens between beds 80 and 81 in the northwestern part of the 

township contains no bed of clean coal over 1 foot in thickness, as 

shown by graphic sections 1124 to 1126, Plate 21. Another lens 

just below bed 82 contains from 6 inches to 4 feet 6 inches of coal at 

locations 1134 to 1138, as shown by the corresponding graphic sections in Plate 21. Measurements of a lens which splits off bed 83 

in the NW. % sec. 23 are represented in Plate 21 by sections 1144 to 

1146, which exhibit a maximum thickness of 4 feet of coal broken 

by one or more partings. At location 1171, in the NE. % sec. 10, 

a lens overlying bed 86 contains 3 feet 6 inches of coal in its upper 

part and several beds of coal less than 1 foot thick intercalated with 

thicker beds of carbonaceous shale in its lower part. 

6175 29 6
76 HANNA AND CARBON BASINS, CARBON COUNTY, WYO. 

T. 24 N., RS. 80 AND 81 W.

^Except for the small asymmetric anticline in the southeast corner 

6ft. '24 N., E. 81 W., the Hanna formation dips from 3° to 90° S. 

in T. 24 N., Rs. 80 and 81 W.; the steepest dips' occur along the 

northern margin of its outcrop. Along Medicine Bow River the 

Hanna beds are dissected into picturesque badlands, but north of the 

river they occupy a rolling plain. Older rocks down to the Carboniferous occupy the foothills in the unmapped portions of these 

townships and are complexly folded and faulted.

The coal in these townships occurs in the Hanna formation and is 

associated with too many thick beds of carbonaceous shale to be of 

any economic value. Bed 86, the lowest coal, contains about 1 foot 

of coal at locations 1160 and 1161, in sees. 33 and 32, respectively, 

T. 24 N., R. 81 W. Bed 87 consists of carbonaceous shale and bone 

at location 1170, in the SW. 14 sec. 31, T. 24 N., R. 80 W.

Bed 88 contains as much as 100 feet of carbonaceous shale, interstratified with which are coal beds, ranging from a few inches to 11 

feet in thickness, as shown by graphic sections 1172, 1173, and 1180, 

Plate 19.

Bed 89 also consists of about 100 feet of carbonaceous shale with 

numerous interstratified beds of coal, as shown by graphic sections 

1181 to 1183, Plate 19. Other beds of coal ranging in thickness from 

a few inches to over 4 feet occur interbedded with greater thicknesses 

of carbonaceous shale at locations 1188, 1656, 1657, and 1660 to 1662.

TPS. £0 AND 21 N., R. 80 W.

The Saddleback Hills, a long, narrow anticline developed in the 

resistant sandstones of the Mesaverde formation, attain a maximum 

altitude of 7,843 feet above sea level in the western part of T. 21 N., 

R. 80 W., and rise about 500 feet above an encircling valley of Lewis 

shale. East of the anticline the Lewis shale is overlapped by the 

Hanna formation, the basal sandstone of which forms a prominent 

escarpment separating the Lewis shale valley from the uneven uplands included in the Carbon Basin.

The Mesaverde, Lewis, and Medicine Bow beds dip about 65° W. 

in the western limb of the Saddleback Hills anticline, though in 

places they stand vertical. In the eastern limb the average dip is a 

little less, though local exposures show vertical and even overturned 

beds. (See cross section M-N, pi. 27.) The Hanna beds dip from 

10° to 20° toward the center of the Carbon Basin in their southern 

and western.exposures, but lie flat in the center of the basin.

The Mesaverde formation contains five coal beds in various parts 

of the Saddleback Hills anticline. These beds, with the exception of 

bed 90, occur near the top and bottom of the uppermost group of
ECONOMIC GEOLOGY .

sandstones in the formation and can not be traced continuously 

because of poor exposures.

Bed 90 occurs near the axis of the anticline and contains a rather 

persistent bench of coal from 1 to 4 feet thick, broken in manj/ places 

by partings of shale, as shown by graphic sections 1211 to 1222, 

Plate 22.

Measurements of bed 91 in the north end of the anticline are represented graphically in Plate 22 by sections 1223 to 1228, which show 

from 6 inches to 2 feet 6 inches of coal.

Bed 92 is less than 100 feet above bed 91 and contains from 1 foot 

7 inches to 3 feet 5 inches of coal at locations 1229 to 1234, as shown 

by the corresponding graphic sections in Plate 22.

Bed 93 crops out in the eastern limb of the anticline in-the northern 

part of T. 21 N. At location 1237, in the SE. ty sec: 9 it 'exhibits 

over 6 feet of coal, but elsewhere it is thin or bony, as shown by 

graphic sections 1235,1236, and 1238, Plate 22.

A measured section of bed 94 at location 1240, in the SE. % sec. 5, 

T. 21 N., shows less than 3 feet of coal. This bed does not occur in 

the eastern limb of the anticline.

At location 1253, in the SE. % sec. 6, T. 21 N., bed 96, the lowest 

coal in the Medicine Bow formation in this township, contains about 

2 feet of coal. Other sections of the bed were not obtained in this 

township.

Measurements of bed 97 at locations 1268, in the SW. *4 sec. 7, T. 21 

N., and 1269, in the SE. 14 sec. 6, exhibit less than 2 feet of good coal.

Bed 98 consists of two benches of coal which are 30 feet apart at 

location 1272, in the SW. % sec. 7, T. 21 N., and 15 feet apart at location 1273, in the SE. 14 sec. 6. -The thickest individual bench occurs 

at location 1273 and contains 4 feet of coal.

The Johnson bed is the lowest coal in the Hanna formation in 

these townships and is principally developed along the boundary line 

between them. At the Wilson mine, in the SE. 14 sec. 32, T. 21 N., 

it attains a maximum thickness of 22 feet for these townships. The 

mine has an entry 250 feet long, 30 feet wide, and 15 feet high, and 

the coal mined is used by settlers in the general vicinity. An analysis 

of the coal in this mine is given on page 35. Two entries on the 

Johnson bed at the Kent mines, in the NW. 14 sec. 2, T. 20 N., were 

caved in when examined in 1925. The coal is 14 feet thick in these 

entries and dips 5° NE. According to settlers, coal was last taken 

from this mine in the winter of 1923 and was hauled to Medicine 

Bow in trucks. Other measurements of the Johnson bed in these 

townships show from 9 to 17 feet of coal, as shown by graphic sections 1290 and 1292 to 1296, Plate 22.

The Finch bed is approximately 100 feet above the Johnson bed at 

location 1319, in the SE. 1/4 sec. 34, T. 21 N., but the interval varies
78 HANNA AND CARBON BASINS, CARBON COUNTY, WYO. \

from place to place. Although the bed can be traced continuously 

around the southern arid western sides of Carbon Basin to a point just 

north of this township, it is thickest in the southwestern part of the 

basin, its maximum thickness of 32 feet occurring at location 1312, in 

the NW. 14 sec. 28. Other measurements of the bed showing thicknesses ranging between 1 and .27 feet are shown graphically; in Plate 

22liy sections 1305 to 1311 and 1313 to 1321.

The Johnson mine, on the Finch bed in the SE. !/4 sec. 32, consists 

of a single entry about 250 feet long and 25 feet wide. Two rooms 

have been driven off the main entry for about 100 feet. The coal bed 

is about 13 feet thick, of which 9 feet is mined and the rest left 

for roof. About 500 tons of coal is mined here annually for local 

consumption. An analysis of the coal in this mine is given on page 

35. The West mine, just west of the Johnson mine, is an entry 75 

feet long and 25 feet wide on about 10 feet of coal. About 25 tons 

annually is mined here for use at the West ranch.

Bed 105 contains about 2 feet of coal at locations 1343 to 1346, in 

sees. 35 and 36, T. 21 N., and sec. 2, T. 20 N.

North of location 1347 a, in the SE. % sec. 16, T. 21 N., bed 106 

and the Finch bed unite and were mapped as one bed. South of 

location 1347 a, bed 106 ranges between 2 and 4 feet in thickness, as 

shown by graphic sections 1347 a, 1347 b, 1347 c, and 1347 to 1358,. 

Plate 22.

Bed 107 occurs in the southern part of T. 21 N. and contains less 

than 2 feet of coal at locations 1364 to 1369, as shown by the corresponding graphic sections in Plate 22.

At location 1376, in the NE. % sec. 27, T. 21 N., bed 108 contains 

four benches of coal, each less than 2 feet thick, separated by thicker 

beds of shale. Smaller measurements of the bed in this township 

are represented graphically in Plate 22 by sections 1371 to 1375 and 

1377.

Bed 109 was traced from the Carbon No. 7 mine, near the northeast 

corner of T. 21 N., along the east and south sides of Carbon Basin, 

but does not occur along the west side. In the southern part of the 

basin the bed is associated with thick beds of carbonaceous shale, and 

it is impossible to tell whether the thickest benches of coal in some of 

the sections represent a continuous stratum or are more persistent 

lenses. Measurements of the bed made at locations 1379 to 1386 and 

1389 to 1392 and plotted graphically in Plate 22 show that it consists 

of one or more beds of coal, ranging between 1 and 5 feet in thickness, 

separated by beds of shale.

Bed 110, like bed 109, is cut in two by Second Sand Creek in 

sees. 23 and 24, T. 21 N., and contains less than 1 foot .of coal at 

localities 1400 and 1401.
ECONOMIC GEOLOGY 79

South of Second Sand Creek, at locations 1408 to 1411, bed 111 

contains less than 4 feet of coal, as shown by the corresponding 

graphic sections in Plate 22. At locations 1406 and 1407, north of 

the creek, its thickest bench contains 2 feet 6 inches of coal.

The Carbon No. 6 bed crosses the northeast corner of T. 21 N. 

and extends around the north and west sides of Carbon Basin as far 

south as sec. 10. Sections of it at locations 1417, in the SE. % sec- 3, 

and 1418, in the NE. 14 sec. 3, show less than 4 feet of coal.

At location 1437, in the NE. % sec. 6, T. 20 N., a lens of coal 

between the Johnson and Finch beds contains about 2 feet of coal, 

"but at location 1436, in the center of sec. 32, T. 21 N., it is less than 1 

foot thick. Sections 1438 and 1439 are measurements of a bench 

that splits off from the Finch bed near the southeast corner of sec.

 29, T. 21 N., and contains less than 3 feet of coal. Another lens at 

location 1440, in the SW. 14 sec. 36, shows 1 foot 6 inches of coal. 

A lens that splits off from bed 106 in the SE. 14 sec. 21 was measured 

at locations 1441 to 1444 and exhibits from 6 inches to 4 feet of coal, 

;as shown by the corresponding sections in Plate 22.

The outlier in the center of sec. 33, T. 21 N., shows 4 feet of coal 

at location 1445 and may represent bed 106. Another outlier in the 

SW; 14 sec. 23 probably represents bed 110 and "contains less than 2 

feet of coal at location 1446. Sections 1447 to 1450 are on outliers 

in sees. 22 and 27, and all probably represent the same bed. The 

thickest individual bench at any of these locations contains less than 

2 feet of coal. Section 1451 shows 2 feet 8 inches of Coal, which

 crops out in the small hill near the southwest corner of sec. 15.

T. 22 N., R. 80 W.

The Saddleback Hills anticline plunges northward across the central part of T. 22 N., E. 80 W., and is bordered on the east by the 

Carbon Basin, which is connected with the Hanna Basin to the northwest by a narrow syncline occupying the northeast corner of the 

township. (See cross section K-L, pi. 27.) Several small faults 

with a vertical displacement of less than 100 feet occur in the mines at 

Carbon, but were not detected elsewhere in the township.

Two prominent landmarks rise above all others in this township. 

One of these is the high hill of Ferris beds that attains an altitude

 of 7,419 feet, or 400 feet above the surrounding area, in the SW. !/4 

sec. 8, and the other is the Mesaverde ridge at the north end of the 

:Saddleback Hills anticline, which just south of the township line 

attains an altitude of 7,796 feet, or about 900 feet above the adjoining 

lowlands of Lewis shale. Except for these features and the escarpments formed by the basal sandstones in the Medicine Bow and 

llanna formations, the surface of this township is fairly even.
80 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

Coal beds occur in all the formations exposed in the township except the Lewis shale. The most valuable beds, however, are in the 

Manna formation.

Bed 94 occurs at the top of the Mesaverde formation in sec. 33 and 

consists of alternating beds of coal, bony coal, shale, and sandstone 

ranging through an interval 5 to 18 feet thick. No single bench of 

coal exceeds 3 feet in thickness, however, as shown by graphic 

sections 1241 to 1244. Plate 23.

The Medicine Bow coals in this township occur near the base of the 

formation and are inclined from 3,0° to 60°. Bed 95-A, the lowest 

coal, ranges between 10 inches and 5 feet 4 inches in thickness in this 

toAvnship, as shown by graphic sections 1274 to 1282, Plate 23.

Bed 96-A is about 100 feet below bed 96 and is confined to the 

northern exposures of the formation. Measurements of it made at 

locations 1283 to 1289 and represented graphically on Plate 23 

exhibit from 2 to 4 feet of coal.

Bed 96 is the highest and most valuable Medicine Bow coal in this 

township. At location 1256, in the SW. ^4 sec. 29, it contains 8 feet 

6 inches of coal. Smaller measurements of it made at locations 1254, 

1255, and 1257 to 1264 are represented graphically in Plate 23. ;

Measurements of isolated Medicine Bow coals made at locations 

1280 and 1461 to 1462 show 2 feet or less of coal.

At locations 1468 to 1470, in the SW. 14 sec. 12 and vicinity, alternating beds of coal, shale, and sandstone in the Ferris formation 

occupy a maximum interval of 17 feet. The corresponding graphic 

sections in Plate 23, however, show no single bench of coal over 4 

feet thick.

The Carbon No. 4 and No. 5 beds are the best coal beds in the 

Hanna formation in the northern part of the Carbon Basin. The 

Carbon No. 5 bed is fairly well exposed between the SE. 14 sec. 22 

and the NW. 14 sec. 13 and contains a .maximum thickness of 13 feet 

of coal at location 1466, in the NW. 14 sec. 14. Smaller measurements of this bed in this township are represented graphically in 

Plate 23 by sections 1463 to 1465 and 1467. The Carbon No. 4 bed 

is about 50 feet above the Carbon No. 5 bed and exhibits 6 feet 6^ 

inches of coal at location 1472, in the center of sec. 14. Nothing 

comparable to this bed was found elsewhere in the vicinity.

The Carbon No. 6 bed is the one formerly exploited in the Carbon 

No. 6 mine and probably in the Carbon No. 2 mine. Between location; 

1423 and the Carbon No. 2 mine it averages about 7 feet in thickness,, 

as shown by the corresponding graphic sections in Plate 23. At location 1426, south of the fault that passes through the No. 2 mine, a; 

bed tentatively correlated with the Carbon No. 6 bed exhibits coal, 

shale, and carbonaceous shale distributed through an interval of
ECONOMIC GEOLOGY 81

about 55 feet. Other sections measured at locations 1427 to 1429 

show from 2 to 7 feet of coal. '

The Carbon No. 7 bed was formerly exploited in the Carbon No. 7 

mine, in the SE. 14 sec- 36, where it was measured and sampled in 

two places by Veatch in 1906. Sections taken by him about 800 feet 

from the mouth of the main slope exhibit about 8 feet of coal, as 

shown by the graphic sections in Plate 23.

Isolated exposures of Hanna coal at locations 1473, in the NE. 14 

sec. 34, and 1205, in the NW. % sec. 4, show less than 2 feet of coal.

T. 23 N., R. 80 W.

A very prominent hogback of Mesaverde sandstone rises abruptly 

above Steele shale badlands in the northern part of T. 23 N., R. 80 

W., and is overlapped by the Hanna formation in sec. 4. (See pi. 

6, B.) Peneplaned surfaces of the Lewis, Medicine Bow, and Ferris 

formations end abruptly either at the .southern edge of the extensive 

Hanna badlands in the northwestern part of the township (see pi. 7, 

A) or against the prominent escarpment that borders the dissected 

table-land in the western part of the township. In broad terms the 

strata in this township occupy the eastern and .southern limbs of a 

syncline which is poorly defined because of the unconformable relations between the Hanna and underlying formations. At the point 

where the Hanna overlaps the older formations the beds are closely 

plicated and flexed, but elsewhere they dip about 15° W. The three 

normal faults mapped in the southwestern part of the township have 

displaced the strata only a few hundred feet.

Bed 78-A is about 4,300 feet above the base of the Hanna formation and has been traced across the township. Although it is as much 

as 40 feet thick, it consists largely of carbonaceous shale and bone, the 

thickest individual bench of coal being about 6 feet thick, as shown by 

graphic sections 1014 to 1023, in Plate 24.

Bed 78-B lies 35 feet above bed 78-A and has about the same surface distribution. At location 1050, in the SW. x/4 sec. 28, it contains 

about 15 feet of coal split in the middle by a 6-inch parting of carbonaceous shale. Other sections in this township showing individual 

benches of coal from 1 to 9 feet thick interstratified with beds of shale 

and bony coal are represented graphically in Plate 24 by sections 1026 

to 1029 and 1031 to 1034.

Bed 79 occurs 125 feet above bed 78-B and resembles it in being 

badly broken by shale partings in the northern part of the township 

but becoming cleaner farther to the south. Measurements of it made 

at locations 1045 to 1052 and represented graphically in Plate 24 

show individual benches of coal from 1 to 10 feet thick interstratified 

with beds of carbonaceous shale and bony coal.
82 HANNA AND CARBON BASINS, CARBON COUNTY, WYO.

Bed 80 in this township probably represents beds 81-A and 82-A 

in T. 22 N., R. 81 W. At locations 1000 to 1003 it contains about 6 

feet of coal in an upper bench and from 1 to over 6 feet of coal in one 

or more lower benches, as shown by the corresponding graphic sections 

in Plate 24.

Bed 81 is 200 feet above bed 80 and may be equivalent to the Hanna 

No. 1 bed of T. 22 N., R. 81 W. It nowhere contains as much as 5 

feet of good coal, as illustrated by graphic sections 1120 to 1123, 

Plate 24.

Measurements of bed 87 at locations 1167 to 1169 show alternating 

beds of coal and carbonaceous shale distributed through a maximum 

interval of 11 feet. No individual bench of coal exceeds 3 feet in 

thickness. (See pi. 24.)

Bed 88 lies 200 feet above bed 87 and contains four benches of 

 coal, none of which exceeds 4 feet in thickness, distributed through 

.a maximum interval of about 20 feet, as illustrated by graphic sections 1177 to 1179, plate 24.

Bed 89 is the highest coal bed in the township and contains no 

.single bench of coal as much as 3 feet thick at locations 1184 to 

1187, as shown by the corresponding graphic sections in Plate 24.

At locations 1189 and 1190, in sec. 28, a bed which may be part 

of bed 78-A contains 3 feet 4 inches and 5 feet 6 inches, respectively, 

of coal. Other coal beds occur near the base of the Hanna formation 

in sec. 15 and vicinity, but are too badly squeezed, crushed, and 

folded to be of economic value. Measurements of these beds at locations 1191 to 1204 are represented under the heading of lenses in 

plate 24 by the corresponding graphic sections. The beds measured 

.at locations 1206 and 1207, in the SE. % sec. 33, occupy about the 

same stratigraphic position as the lenses described above and contain 

about 2 feet of poor coal.

At locations 1208 to 1210, in sees. 13 and 14, a coal bed in the 

Medicine Bow formation contains from 2 to 13 feet of coal, but could 

not be found beyond the points indicated on the map.

TPS. 20 AND 21 N., R, 79 W.

The Medicine Bow anticline, outlined by the resistant sandstones 

in the Mesaverde formation, occurs in the southeastern part of T. 

21 N., R. 79 W., and rises about 500 feet above the surrounding valley 

of Lewis shale. The dip of the strata increases uniformly away from 

the axis of the anticline until a maximum inclination of about .30° 

is reached in the hogback of light-gray sandstone which characteristically marks the top of the formation. The Hanna formation 

occupies the eastern part of the Carbon Basin in this township and 

overlaps the Medicine Bow formation. These formations have a
ECONOMIC GEOLOGY 83

maximum dip of'about 45° and occupy broken areas containing many 

flat-topped buttes.

Bed 99 occurs about 600 feet above the base of the Mesaverde formation in the Medicine Bow anticline and contains no single bench of 

coal as much as 2 feet thick at locations 1326 to 1328, as shown by

the corresponding graphic sections in plate 25.

Bed 100 occurs at the top of the Mesaverde and is about 7 feet 

thick at locations 1329 and 1330, in sees. 34 and 27, T. 21 N., respectively.

Beds 101 to 104 occur in the Medicine Bow formation in the northeastern part of T. 21 N. and average about 2 feet in thickness, as 

illustrated by graphic sections 1331 to 1335 and 1338 to 1340, plate 

25. Lenses at locations 1341, in the NW. 3/4 sec- Hj anc^ 1342, in 

(he NE. 14 sec. 16, show about 2 feet of coal.

At location 1303, in the SE. % sec. 20, T. 21 N., the Johnson bed, 

the lowest coal in the Hanna formation in these tOAvnships, contains 

11 feet of coal. Smaller measurements of it in these townships 

and in T. 20 N., K. 80 W., are represented graphically in Plate 25 

by sections 1297 to 1302 and 1304. The Johnson mine in sec. 6, 

T. 20 N., is a small entry from which coal is taken to supply the Johnson ranch on Medicine Bow River. An analysis of the coal in this 

mine is given on page 35.

At locations 1323 to 1325 the Finch bed contains no single bench 

of coal as much as 3 feet thick, as illustrated in the corresponding 

graphic sections in Plate 25.

At location 1363, in the center of sec. 16, T. 21 N., bed 106 contains 

6 feet of undivided coal in its lowest bench. Elsewhere in these 

townships it consists largely of carbonaceous shale and bone, as 

shown by graphic sections 1359 to 1362, Plate 25.

Bed 107 was measured in these townships only at location 1370, 

in the NW. 14 sec. 31, T. 21 N., where it contains 5 feet 4 inches of 

undivided coal.

The Carbon No. 7 bed contains five benches of coal ranging between 

1 and 6 feet in thickness at location 1457, in the NW. % sec. 6r 

T. 21 N. South of this location, however, it is about 2 feet thick, as 

shown by graphic sections 1453 to 1456, Plate 25.

Graphic sections 1430 to 1435, Plate 25, show the Carbon No. 6 

bed in T. 21 N., E. 79 W., to consist of about four benches of coal 

separated by beds of carbonaceous shale. The thickest single bench, 

contains about 3 feet of coal at location 1433, in the NE. 1/4 sec- 17-

Bed 108 contains less than 1 foot of coal at location 1378, in the 

SW. % sec. 30, T. 21 N.

Bed 109 contains 2 feet 6 inches of undivided coal at location 1396, 

in the NE. !/4 sec. 17, T. 21 N. Smaller measurements of it in
84 HANNA AND CARBON BASINS, CAEBON COUNTY, WYO.

T. 21 N. are represented graphically in Plate 25 by sections 1387, 

1388,1393 to 1395, and 139T to 1399.

Bed 110-A contains less than 2 feet of coal at locations 1402 to 

1405, in T. 21 N., and is equivalent to either bed 110 or bed 111 of 

T. 21 N., R 80 W.

Smaller outliers of a bed not far above the Finch bed exhibit less 

than 2 feet of coal at location 1459, in the NE. % sec. 6, T. 20 N., 

R. 79 W.

T. 22 N., R. 79 W.

The surface of T. 22 N., R. 79 W., is largely a peneplain, the more 

resistant Mesaverde and Medicine Bow beds being worn down to 

practically the same level as the less .resistant Lewis and Steele 

shales. The southwestern part of the township, however, is hilly and 

is crossed by a small syncline, which pitches to the northwest. Elsewhere' in the township the strata have a monoclinal dip to the west 

ranging between 25° and 50°.

Thin beds of coal occur in the Mesaverde and Medicine Bow formations in this township, but because of their steep inclination, 

thinness, and irregularity they are of but little economic value at 

present.

Bed 112 occurs in the middle of the Mesaverde formation and contains less than 2 feet of coal at locations 1412 to 1414. Bed 112-A 

occurs at the top of the Mesaverde and contains 5 feet and less of 

bony coal at locations 1415 and 1416. At the Wissler mine, in the 

NE. 14 sec. 22, bed 112-A contains 4 feet of coal. When the mine 

was examined in July, 1925, the shaft was down about 140 feet and 

the output averaged 2 tons of coal a day. An analysis of the coal 

from this mine is given on page 35.

At locations 1336 and 1337, in sees. 32 and 33, bed 104 contains 

about 2 feet of coal. An isolated exposure of coal in the Medicine 

Bow formation near the southwest corner of sec. 8 contains 1 foot 

8 inches of coal.

OIL DEVELOPMENTS

Practically all the folds in the Hanna and Carbon Basins that 

might serve as reservoirs for oil have been tested, and in only one, 

the Saddleback Hills anticline, has oil been found in commercial 

quantities. The general synclinal character of the basins and the 

great thicknesses and'wide'distribution of the Tertiar}7 coal-bearing 

rocks practically preclude the possibility of finding oil in commercial quantity where rocks younger than the Lewis shale crop 

out, except possibly along the borders of the basins where anticlines 

may be concealed by the overlapping Hanna and North Park 

formations.
OIL DEVELOPMENTS 85

The folds once considered to hold the greatest promise of oil production in the Hanna and Carbon Basins are the Fort Steele, Cedar 

Ridge, and St. Marys anticlines, in the Walcott quadrangle; the 

Pass Creek Ridge anticline, in the Walcott and Hanna quadrangles; 

and the Saddleback Hills, Alien Lake, Oil Springs, and Flat Top 

anticlines, in the Saddleback Hills quadrangle. The structure of 

these folds is described in'the section on structure and in the individual township descriptions. Structure sections of the folds are 

, shown in Plate 27, and their oil possibilities are discussed in a Geological Survey press notice. 23 In view of these facts, this part of 

the report will be devoted only to a history of drilling operations on 

the folds.

HISTORY OF DRILLING OPERATIONS

Fort Steele anticline. The Fort Steele anticline, within the limits 

of the Walcott quadrangle, has been tested by the Ohio Oil Co. in the 

NW. % sec. 28, T. 21 N., R. 85 W., and by the Fort Steele Petroleum 

Co. in the NW. % sec. 22 of the same township. The Ohio well, 

located on the axis of the anticline, Avas drilled to a depth of 2,250 

feet in 1921 and obtained water in the uppermost sand in the 

Cloverly formation. The Fort Steele well, drilled in 1918, was located about a mile north of the axis of the anticline and encountered 

several shows of oil and gas before being abandoned at a depth of 

3,540 feet.

Cedar Ridge, St. Marys, and Pass Greek Ridg-e anticlines. The 

Producers & Refiners Corporation has drilled three wells on the St. 

Marys anticline in T. 21 N., R. 84 W., all of which were dry holes. 

The first well was drilled in the NE. V4 sec- 10 in 1925 and was 

abandoned at a depth of 800 feet. The second well, in the NE. % 

sec. 9, was abandoned in 1926 at a depth of 2,055 feet. The Quealy 

sand, the oil-producing sand in the Saddleback Hills anticline, was 

reported to show slight quantities of oil and gas in this well at a 

depth of 1,059-1,100 feet. The third well, in the NW. y4: sec. 14, 

obtained water in the Quealy sand at a depth of 765 feet, was drilled 

to a. depth of 1,012 feet, and was then abandoned in 1926. According to the interpretation of the structure in the St. Marys anticline, 

us given in structure section E-F, Plate 27, all these wells were located 

too far to the southwest to strike the crest of the Cloverly upfold, 

which lies deeply buried northeast of the surface ridges. Furthermore, chances for commercial oil production in the Quealy sand are 

believed to be slight because of the sharpness of the folding and 

the shearing, crushing, and faulting to which the rocks have been 

subjected.

::a Coal and oil resources of the Hanna Basin, Carbon County, Wyo.: U. S. Geol. Survey 

prose notice 12514, 1922.
86 HANNA AND CARBON BASINS, .CARBON COUNTY, WYO.

Saddleback Hills anticline. Oil was discovered in the Saddleback 

Hills anticline (Simpson Ridge) in June, 1923, by the Producers & 

Refiners Corporation. Oil was encountered in the Quealy sand, 

which occurs in the transition zone at the base of the Mesaverde 

formation, at a depth of 680 feet, and for a short time oil ft&wed 

over the top of the 15-inch casing. The oil was cased off, and drilling 

continued to a depth of 6,931 feet. Neither the Wall Creek (?) sandstone nor the sandy shales composing the Cloverly formation contained oil, and the well was plugged back to 680 feet to recover oil 

from the Quealy sand. The log of this well is shown graphically 

in Plate 26.

Production in the Saddleback Hills anticline is confined to sec. 20r 

T. 21 N., R. 80 W., where eight wells produce about 200 barrels of oil 

a day from the Quealy sand. This oil is transported to the Union 

Pacific Railroad at Hanna and carried to the refinery at Parco.

Alien Lake anticline. The first well on the Alien Lake anticline 

was drilled in 1918 and 1919 by the Cosden Oil & Gas Co., in the 

NW. % sec. 34, T. 23 N., R. 79 W. Water was struck in the Wall 

Creek (?) sandstone at a depth of 275 feet, and about 4,000,000 cubic 

feet of gas between depths of 936 and 1,063 feet. The Muddy sand 

contained 35,000,000 cubic feet of gas between depths of 1,357 and 

1,397 feet. At a depth of 1,419 feet the hole filled up with water 

from the uppermost sands in the Cloverly formation, and the well 

was abandoned. A well started in 1923 by the Laramie Oil & Gas 

Syndicate about half a mile southeast of the Cosden well was reported to have encountered 3,500,000 cubic feet of gas between depths 

of 1,330 and 1,343 feet. The sands in the upper part of the Cloverly 

formation were struck at a depth of 1,508 feet and were reported to 

yield 35,000,000 cubic feet of gas and a strong flow of water. About 

7,000,000 cubic feet of gas, with only a small amount of water, was 

reported to-have'been struck between depths of 1,685 and 1,691-feet, 

in a sand probably belonging to the lower part of the Cloverly 

formation. The well was later taken over by the Kanawha Oil Co. 

and plugged back to 1,341 feet in an unsuccessful attempt to obtain 

the gas originally recorded at that depth. The graphic log of this 

well is included in Plate 26. A well drilled by the Western States 

Oil & Land Co., in the NE. i/4 sec. 11, T. 22 N., R. 79 W., was 

abandoned at a depth of 2,035 feet without reaching the Cloverly 

sandstones.

Oil Springs anticline. The Oil Springs anticline was tested in the 

SW. % sec. 20, T. 23 N., R. 79 W., by the Ohio Oil Co. in 1918 and 

1919. Shows of gas were encountered between depths of 1,127 and 

1,165 feet. Water was found in the uppermost sands of the Cloverly 

formation at a depth of 1,480 feet, and the well was then abandoned^
INDEX

Acknowledgments for aid..

Alien Ifek&anticline; weHs drilkslron-.

Alha}t)) occurrence of..

Page

3

86

27

Beck, Elfred, acknowledgment to.

Cartile shale, features of....________ 16 

Casper formation, rocks designated as.... _ 11 

Cedar Ridge anticline, features of._____ 28 

Cedar Ridge fault, features of.._______ 31 

Chugwater formation, features of. _____ 12

plate showing_______________ 26 

Cloverly formation, nature of.._______ 14-15

plate showing______________ 26 

Coal, analyses of...._.....___......._ 33-37

description of beds by townships, scope

of............................... 38

formations containing._________ 31-32

production and uses of.... ...... 37

- properties of______________ 32-37

quantity^._______.______ 37-38 

Como "Ridgef'se'ction Of'Stmdance formation

at............................... 13

Cronberg, Albert, acknowledgment to, __. 3

Drainage of the area.

Embar (?) formation, nature and occurrence

of............... .............. 11-12

Faults in the rocks.....___.___....... 30-31

Ferris formation, nature of.____.-__.- 24-25 

plate showing......... . 28

vertical beds in, ptete showing....._... 26

Field work, record of .__... ... 2-3 

.Flat?Eflp,anticline,.features of.._...__.. 29-30 

Folds-.lathe area....____.__ _ 27-30

Fort Steele, section of Mesaverde formation

north of.... ..... .... 19-21

Fort Steele anticline, features of... ... 27

wells drilled on.__.. . 85

Frontier formation, nature of..__ _ 16

Geography of the area.-__-_ . 6-9

Hanna formation, nature of. . 25-26 

plates showing________.. _ 26,42 

Hauna quadrangle, columnar section of rocks

exposed hi__.. . 42 

Hayden, F. V., quoted.. .. . 3-4 

Hodge, James T., quoted_..... . 5-6

King, Clarence, quoted.

Lew is shale, nature and occurrence of..... 21 

sandstone hogback in, plate showing..... 26

Page

Little Medicine Bow River, section of Morrison formation on.....______ 14 

L/ocation of the area..........__...__. 1-2

McAuliffe, Eugene, acknowledgment to_.. 3 

Medicine Bow formation, nature of..____ 23-24

plate showing....__..____._.__ 26 

Mesaverde formation, nature and members

of................................ 17-21

plates showing........................... 26,42

Mining development, outline of....___.. 6

Morrison formation, nature of...___..__ 13-14

plates showing........................... 26

Mowry shale, features of...__ __.__ 15-16

Niobrara formation, features of..._. .... 16-17

North Park formation, nature of...__._.. 26

plate showing...._____.___.__ 42

Oil developments in the area......_____ 84-86

Oil Springs anticline, plate showing_ .... 42

well-drilled on........._;_............ 86

Pass Creek Ridge, anticline, features of.__ 29

Pryde, O. B., acknowledgment to. ... 3

Purpose of the survey..___ 2

Rattlesnake Hills, section of Mesaverde

formation in______ . . 19-21 

Roads and railroads of the area.... 8-9

Saddleback Hills anticline, features of. .. 29

oil wells on.............................. 86

Saddleback Hills quadrangle, columnar section of rocks exposed in. 42 

St. Marys anticline, features of. 28-29

weHs^drilled on.......................... 85

St. Marys fault, features of..__._ .... 30-31

Settlements of the area..._____ 8 

Steele shale, nature of. ____._ 17

plates showing......__ 26

Stratigraphy of the area... ...... 9-27

Structure of the rocks..___..._. 27-31 

Sundance formation, nature of..._ . 12-13

plate showing... __ . 26 

Surface features of the area.. 6-8 

Surveys, earlier..... 3-6

Tensleep sandstone, occurrence of.. 11 

plate showing.. . 26 

Terrace gravel, occurrence of... .. . 26 

Thermopolis shale, features of.... 15

Township descriptions, Tps. 20 and 21 N.,

R. 79 W., coal beds in.......... 82-84

Tps. 20 and 21 N., R. 80 W., coal beds in. 76-79

87
INDEX

Page 

Township descriptions, T. 21 N., R. 81 W.,

coal beds in___............. OS

T. 21 N., R. 82 W., coal beds in......... 62

T. 21 N., R. 83 W., coal beds in......... 50-51

T. 21 N., R. 84 \V., coal beds in......... 42-44

T. 21 N., R. 85 W., coal beds in......... 39-40

T. 22 N., R. 79 W., coal beds in......... 84

T. 22 N., R. 80 W., coal beds in......... 79-81

T. 22 N., R. 81 W., coal beds in......... 68-73

T.'22 N., R. 82 W., coal beds in......... 62-66

T. 22 N., R. 83 W., coal beds in......... 51-56

T. 22 N., R. 84 W., coal beds-in......... 44-45

T. 22 N., R. 85 W., coal beds in......... 40-42

T. 23N., R. 80 W., coal beds in......... 81-82

T. 23 N., R. 81 W., coal beds in......... 73-75

Page 

Township descriptions, T. 23 N., R. 82 W.,

coal beds in..___...__...... 66

T. 23 N., R. 83 W., coal beds in......... 56-59

T. 23 N., R. 84 W., coal beds in......... 45-48

T. 23 N., R. 85 W., coal beds in......... 42

T. 24 N., Rs. 80 arid 81 W., coal beds in. 76 

T. 24 N., R. 82 W., coal beds in......... 67-68

T. 24 N., R. 83 W., coal beds in......... 59-62

T. 24 N., R. 84 W., coal beds in......... 48-50.

Walcott quadrangle, columnar section of

rocks exposed in.. . 42' 

Walcott syncline, features of.. ............ 28

Wall Creek sandstone, featur.es of. 16 

Wilson coal mine, plate showing.. .. 42.