DEPARTMENT OF THE INTERIOR

FRANKLIN K. LANE, Secretary

UNITED STATES GEOLOGICAL SURVEY

GEORGE OTIS SMITH, Director 

Bulletin 656

ANTICLINES IN THE SOUTHERN PART OF 

THE BIG HORN BASIN, WYOMING

A PRELIMINARY REPORT ON THE OCCURRENCE OF OIL

BY

D. F. HEWETT AND C. T. LUPTON

WASHINGTON

GOVERNMENT PRINTING OFFICE

1917
eg. 

\>< 

y. , : ~
CONTENTS.

Page.

Introduction, by David White............................................ 7

Scope of report............................................................. 11

Acknowledgments.......................................................... 12

Field work................................................................. 13

Geography................................................................. 14

Location.............................................................. 14

Topography........................................................... 14

Accessibility........................................................... 14

Climate and vegetation................................................ 15

Water..................:.......-.-.................................... 15

Fuel.................................................................. 16

Geology........................................./........................ 16

Stratigraphy.......................................................... 16

Sequence and correlation of the formations.......................... 16

Carboniferous system.............................................. 17

Madison limestone.............................................. 17

Amsden formation............................................. 17

Tensleep sandstone.............................................. 17

Embar formation.............................................. 17

Triassic system.................................................... 18

Chugwater formation.......................................... 18

Jurassic system..................................................... 18

Sundance formation........................................... 18

Cretaceous (?) system............................................... 18

Morrison formation............................................. 18

Cretaceous system................................................. 19

Cloverly formation............................................ 19

Thermopolis shale,............................................ 19

Mowry shale.................................................. 20

Frontier formation.............................................. 20

Codyshale.................................................... 24

Mesaverde formation........................................... 25

Meeteetse formation........................................... 27

Tertiary (?) system................................................. 27

Lance formation................................................ 27

Tertiary system................................................... 28

Fort Union formation........................................... 28

Waaatch and younger formations................................ 29

Structure.............................................................. 30

Definitions of structural terms..................................... 30

General structure of the Big Horn Basin ........................... 32

Structure of the anticlines and domes.............................. 33

Faults............................................................ 36

Structure contours and their use.................................... 37

224.132
4 CONTENTS.

Page.

Oil and gas............................................................... 41

Mode of occurrence................................................... 41

Data considered..................................'................ 41

Specific information obtained by drilling........................... 41

Occurrence in other fields in Wyoming............................. 45

Hypotheses as to accumulation.................................... 46

Physical and chemical characteristics.................................... 50

General development.................................................. 53

Tested districts.................................................... 53

Bonanza region. ................................................ 53

Torchlight dome................................................ 54

Byron anticline............................................... 54

Lamb anticline................................................ 54

Greybull dome................................................. 54

Shoshone anticline............................................. 54

Oregon Basin domes........................................... 55

Grass.Creek anticline........................................... 55

Buffalo Basin anticline......................................... 55

Elk Basin anticline............................................. 55

Other districts................................................. 55

Refineries......................................................... 56

Pipe lines......................................................... 56

The anticlines and domes.................................................. 56

Sheep Mountain anticline.............................................. 56

Greybull field......................................................... 58

Shell Creek dome and Cherry anticline................................. 67

Lamb anticline........................ 1............................... 70

Torchlight dome...................................................... 75

Dry dome............................................................. 81

Mercer anticline........................................................ 83

Manderson anticline................................................... 86

Paintrock anticline..................................................... 90

Bonanza anticline..................................................... 93

Nowood anticline...................................................... 97

Zeisman dome........................................................ 100

Brokenback anticline.................................................. 102

Sherard dome......................................................... 105

Well area.............................................................. 108

Tensleep anticline...................................................... 112

Bud Kimball anticline................................................. 115

Mahogany Butte anticline.. ............................................. 119

Lysite Mountain anticline.............................................. 121

Black Mountain anticline.............................................. 123

Lake Creek anticline................................ '. .................. 125

Wildhorse Butte anticline............................................... 127

Blue Spring anticline.................................................. 129

Zimmerman Butte anticline............................................. 131

Red Spring anticline.................................................... 133

Thermopolis anticline................................................. 135

Lucerne anticline (including the Gebo dome)........................... 136

Neiber anticline........................................................ 139

Sand Draw anticline.................................................... .142

Waugh anticline....................................................... 144
. ILLUSTRATION'S. 5

The anticlines and domes Continued. Page.

Cottonwood anticline................................................... 147

Wagonhound anticline................................................ 149

""> Grass Creek anticline................................................... 151

Enos Creek anticline.................................................. 158

Little Grass Creek dome................................................ 159

East and West Buffalo anticlines........................................ 161

Gooseberry dome and anticline.......................................... 164

v Sunshine and South Sunshine anticlines................................ 165

Fourbear anticline..................................................... 168

.4 Pitchfork anticline.................................................... 171

Spring Creek anticline.................................................. 174

Frost Ridge dome..................................................... 177

^ Half Moon anticline................................................... 178

Oregon Basin north and south domes.................................... 181

* Shoshone anticline..................................................... 186

Index.................................................................... 189

ILLUSTRATIONS.

PLATE I. Map of the southern part of the Big Horn Basin.................... 14

II. A, Tensleep sandstone on west side of Brokenback anticline; B,

Madison limestone in anticline in Sheep Mountain Canyon.... 16

III. A, Limestone part of the Embar formation near head of No Wood

Creek; B, Red sandstone in middle part of the Chugwater formation on No Wood Creek near Tensleep........................... 17

IV. A, Unconformable contact between white sandstone of the Cleverly 

formation and variegated shale of the Morrison formation near 

Tensleep; B, Thermopolisand Mowry shales near Bonanza...... 20

y. A, Peay sandstone member of Frontier formation on east side of Big 

Horn River near Greybull; B, Frontier formation in Lysite Mountain anticline................................................. 21

VI. A, Lower sandstone of Mesaverde formation near Zinunerman Butte; 

B, Angular unconformity between the Fort Union and Lance formations on Dry Creek near Greybull..'............................ 26

VII. Structure-contour map of Shell Creek dome and Cherry anticline... 68 

VIII. A, Oil thrown into air when well was "shot" on Torchlight dome;

B, Portable drilling rig on Torchlight dome...................... 78

IX. Structure-contour map of Lamb anticline and Torchlight dome... 78

X. A, Surface appearance of No Wood anticline west of No Wood Creek, 

between Bonanza and Tensleep; B, Mahogany Butte, east of No 

Wood Creek, in southeastern part of Big Horn Basin............ 98

XI. Structure-contour map of Paintrock, Manderson, Bonanza, and No

Wood anticlines............................................... 98

XII. Structure-contour map of Zeisman dome and Brokenback anticlin 102

XIII. Map of Well area showing structure contours....................... 108

XIV. Structure-contour map of Tensleep and Bud Kimball anticlines. ......................................................... 114

XV. Structure-contour map of part of Mahogany Butte anticline......... 120
6 ILLUSTEATIOKS.

Page. 

PLATE XVI. A, Black Mountain anticline; B, Fault trace at east end of

Red Spring anticline, near Thermopolis...................... 124

XVII. Structure-contour map of Lysite Mountain, Black Mountain,

and Lake Creek, anticlines................................ 126

XVIII. Structure-contour maps showing two interpretations of ZimmermanButte anticline..................................... 132

XIX. Structure-contour map of Wildhorse Butte, Blue Spring, and

Red Spring anticlines...................................... 134

XX. Structure-contour map of Neiber anticline..................... 140

XXI. Structure-contour map of Thermopolis, Lucerne, Sand Draw,

and Waugh anticlines..................................... 146

XXII. Structure-contour map of Cottonwood and Wagonhound anticlines .................................................... 150

XXIII. A, Standard drilling rig in Grass Creek oil field; B, Cross section of northwest end of Spring Creek anticline.............. 152

XXIV. Structure-contour map of Grass Creek anticline and LLttle

Grass Creek dome.......................................... 160

XXV. Structure-contour map of East and West Buffalo anticlines in

Little Buffalo Basin, and Gooseberry dome and anticline..... 162

XXVI. Structure-contour map of South Sunshine and Sunshine anticlines.................................................... 166

XXVII. Compiled map of Fourbear anticline.......................... 168

XXVIII. Structure-contour map of Spring Creek anticline............... 176

XXIX. Compiled maps of Frost Ridge dome and Half Moon anticline. 178

XXX. A, Outcrop of the massive basal sandstone and coal-bearing 

part of the Mesaverde formation, in sec. 24, T. 52 N., R. 100 

W.; B, Fault in sec. 2, T. 50 N., R. 100 W.................. 182

XXXI. A, Escarpment of basal sandstone of Mesaverde formation 

dissected near crest of low dome in sees. 15, 16, 21, and 22, 

T. 47 N., R. 100 W.; B, Outcrop of the uppermost sandstone (Torchlight (?) sandstone member) of the Frontier formation, east of Elk Butte, in sec. 32, T. 51 N., R. 100 W...... 183

XXXII. Structure-contour map of South and North Oregon Basin

domes..................................................... 184

FIGURE 1. Index map showing location of area examined.................... 11

2. Cross sections of inclined folds of two types, showing the relations of

wells drilled at the crests of the folds......................... 35

3. a, Cross section and perspective sketch of an anticline, showing 

meaning of structure contours; b, structure-contour map of the 

anticline shown in the sketch................................ 39

4. Diagram showing the relation of a bed that is contoured to other

beds either above or below................................... 40

5. Structure-contour map of south end of Sheep Mountain anticline

and Greybull dome......................................... 57

6. Diagram snowing the effect of a fault on the apparent thickness of a

formation.................................................... 61

7. Structure-contour map of Dry dome............................. 82

8. Structure-contour map of Mercer anticline...................... 84

9. Structure-contour map of Sherard dome......................... 106

10. Structure-contour map of Enos Creek anticline.................. 159

11. Compiled map of Pitchfork anticline............................ 172

12. Reconnaissance map of part of Shoshone anticline.............. 187
INTRODUCTION.

By DAVID WHITE.

The information regarding 50 domes and anticlines in the south 

half of the Big Horn Basin, Wyo., given in this report, was gathered 

during geologic examinations made for the purpose of classifying the 

lands in that region according to their content of oil or other minerals. 

The report presents briefly the economic results that pertain to oil 

and gas or to anticlines that may be favorable to their accumulation.

The work of the Geological Survey in formally classifying as mineral 

or nonmineral the public lands withdrawn from entry because they 

were supposed to contain coal, oil, or phosphate was begun in 1906 and 

has been prosecuted energetically since that time. A full account of 

the withdrawals and restorations of oil lands has been published by 

the Survey as Bulletin 623. Of 1,321,316 acres in the State of 

Wyoming that were withdrawn for classification, 339,158 acres have 

been restored to entry as nonmineral land; and about 668,000 acres, 

including parts of the area here described, have been classified as 

oil land and now await congressional action that will provide some 

method of developing the oil and gas.

The work of organizing and supervising the field investigations 

and the mapping necessary for classifying lands supposed to contain 

coal or oil was placed in the hands of M. R. Campbell, who had 

already established the high standards of. structural and economic 

mapping that are now followed for the eastern coal and oil fields and 

that have been adopted by the foremost oil and gas geologists in 

the world, including those engaged in both public and private work. 

At first, in order to get" immediate results, large areas were covered 

by reconnaissance surveys and were mapped by determining direction 

by hand compass and distance by pacing. Very soon, however, this 

crude and hasty method was replaced by triangulation and by 

plane-table mapping on a large scale with telescopic alidade, the 

work comprising stadia traverse and the determination of elevations 

by vertical angles. For a considerable part of the area examined the 

geologists have been obliged to prepare their own base maps. Mr. 

Campbell, with meager allotments of funds and a small geologic 

staff, laid out the regions in projects and so organized and employed

7
8 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

the annual field parties as not only to classify the lands effectively 

and economically but also to work out systematically the general 

stratigraphy, structure, and geologic history of the broad regions 

embracing the coal and oil bearing formations of the West. As 

Mr. Campbell has now been largely relieved of the supervision of 

the Survey's investigations of oil and gas in the West in order to 

lessen his administrative duties and to afford him more time for 

special geologic researches, it is appropriate to note the great advance 

in the knowledge of the upper Mesozoic and older Tertiary formations 

of the fuel-bearing lands in the Western States that has resulted 

directly from the work done under his guidance.

During a large part of the period, approximately 10 years, since 

the Survey began its classifications for the use of the Secretary of the 

Interior and the General Land Office, the pressure for field examinations and for the preparation of'data for classification has been so 

great as to leave the geologists little opportunity to prepare for 

publication either economic or scientific reports on the areas thus 

classified. Yet for Wyoming alone a considerable number of detailed 

descriptions or preliminary economic reports on areas that might 

contain oil and gas have been issued, as is shown by the subjoined 

list, in which the reports are arranged in the order of publication.

Mineral resources of the Bighorn Mountain region [Wyo.], by N. H. Barton: Bull. 

285, pp. 303-310, 1906.

Mineral resources of the Bighorn Basin [Wyo.], by C. A. Fisher: Bull. 285, pp. 

311-315, 1906.

Coal and oil in southern Uinta County, Wyo., by A. C. Veatch: Bull. 285, pp. 

331-353, pis. 10-12, 1906.

Geology and water resources of the Bighorn Basin, Wyo., by C. A. Fisher: Prof. 

Paper 53, 72 pp., 16 pis., 1906.

Geography and geology of a portion of southwestern Wyoming, with special reference 

to coal and oil, by A. C. Veatch: Prof. Paper 56, 178 pp., 26 pis., 1907.

Gas fields of the Bighorn Basin, Wyo., by C. W. Washburne: Bull. 340, pp. 348-363, 

pi. 3, 1908.

The Labarge oil field, central Uinta County, Wyo., by A. R. Schultz: Bull. 340, 

pp. 36A73, pi. 4, 1908.

The Lander and Salt Creek oil fields, Wyo.: The Lander oil field, Fremont County, 

by E. G. Woodruff; The Salt Creek oil field, Natrona County, by C. H. Wegemann: 

Bull. 452, 87 pp., 12 pis., 1911.

The Powder River oil field, Wyo., by C. H. Wegemann: Bull. 471, pp. 56-75, 

pi. 7, 1912.

The Douglas oil and gas field, Converse County, Wyo., by V. H. Barnett: Bull. 541, 

pp. 49-88, pi. 4, 1912.

The Shoshone River section, Wyo., by D. F. Hewett: Bull. 541, pp. 89-113, pi. 5, 

1912.

Geology and geography of a portion of Lincoln County, Wyo., by A. R. Schultz: 

Bull. 543, 141 pp., 11 pis., 1914.

The Moorcroft oil field, Crook County, Wyo., by V. H. Barnett: Bull. 581, pp. 

83-104, pi. 3, 1915.
INTRODUCTION. 9

Possibilities of oil in the Big Muddy dome, Converse and Natrona counties, Wyo., 

by V. H. Barnett: Bull. 581, pp. 105-117, pi. 4,1915.

Oil and gas near Basin, Big Horn County, Wyo., by C. T. Lupton: Bull. 621, pp. 

157-190, pis. 17-18, 1915.

Anticlines in central Wyoming, by C. J. Hares: Bull. 641, pp. 233-279,1917.

The present report by Messrs. Lupton and Hewett gives the results 

of several seasons of <field work done by them and by others and is, 

in effect, an installment of the economic and scientific results accumulated in the course of the classification of the lands. Others now 

nearly completed include a detailed report on the Grass Creek field, 

by D. F. Hewett, and a report on the Salt Creek field, by C. H. Wegemann. Field examinations in the north half of the Big Horn Basin 

are still in progress.

The area described in the following report embraces some productive oil territory in Wyoming that is undeveloped but very promising. Besides the Greybull, Torchlight, and Grass Creek anticlines, 

which are already sufficiently developed to contribute largely to the 

production of oil in Wyoming, there are seven or more domes and 

anticlines in which oil or gas has been struck, but which are not yet 

sufficiently drilled to indicate their value as oil reservoirs. Thus 11 

of the anticlines here described have already proved to be productive. 

About as many more anticlines have been tested by one, two, three, 

or four holes, though some of the holes have not been theoretically well 

located; Most of these anticlines on which the first tests have been 

unfavorable are probably barren of oil, though other test wells drilled 

more nearly on then1 crests may find oil. It must be borne in mind 

that oil development in Wyoming is still in a very early stage and 

that drilling has not yet covered enough ground to indicate the probable productivity of all the anticlines.

The probability that the remaining anticlines and domes described 

in this report may contain oil or gas has been carefully considered 

by the authors, who have noted their form and prominence, their 

mutual relations, their positions in the basin, the formations exposed 

on their axes, and their similarity to like domes and anticlines that 

carry or do not carry oil or gas. So far as can now be determined 

from the surface indications, about half of these are considered 

promising, but the drill, which is the final test, may show that some 

of them are barren and that others which are now regarded as less 

promising may be productive. It is highly probable that half or 

more of the anticlines and domes here- described constitute a large 

part of the most promising undeveloped oil territory in Wyoming. 

The Big Horn Basin seems to be destined to furnish a large contribution to the Nation's supply of high-grade oil.

ANTICLINES IN THE SOUTHERN PART OF THE BIG HORN 

BASIN, WYOMING: A PRELIMINARY REPORT ON THE 

OCCURRENCE OF OIL

By D. F. HEWETT and C. T. LUPTON.

SCOPE OF BEPOKT.

This report has been prepared to meet demands by oil and gas 

operators and others for information regarding possible oil and gas 

fields in the Big Horn Basin, Wyo. (See fig. 1.) Some of the antiFIGURE 1. Index map showing location of area examined.

clines considered now yield oil and gas in commercial quantities; 

others are believed to be fairly good reservoirs; and still others 

obviously do not contain oil or gas in commercial quantities. The

11
12 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

field work done in most of the area has been complete enough to 

warrant the publication of more detailed descriptions of the geologic 

features than those here given, and reports containing such descriptions are in preparation. Only reconnaissance work was done in 

some parts of the area, however, but all the information obtained 

by such work is given here.

The purpose of the authors has been to set forth briefly and clearly, 

by means of maps, cross sections, and descriptions, the essential 

information collected and the conclusions that may be drawn from 

them, so that not only engineers but persons who have had little or 

no technical training may learn the possibility of obtaining oil and 

gas in any part of the area considered.

With the exception of small upfolds in the Wasatch formation, all 

the known anticlines that are of possible economic value as oil or 

gas reservoirs in the Big Horn Basin south of a line drawn through 

Greybull and Cody are considered in this report. These anticlines 

are not only described separately but are shown by cross sections and 

are represented on the maps by structure contours.

The oil discovered in the Big Horn Basin, except that struck in 

two wells in the Lamb anticline, is of the "light" variety that is, 

it contains large percentages of gasoline and kerosene. In general, its 

specific gravity ranges from 0.8485 to 0.7865, or from 35° to 48° 

Baume". Most of the gas is "wet" that is, it contains some gasoline and ranges in content of methane from 39 to 94 per cent. Its 

content of nitrogen ranges from 0.75 to 15.5 per cent. The oil is 

piped to the railroad at Chatham and Greybull, where it is refined or 

shipped to refineries in other parts of the country. Some of the gas 

is used locally to generate power for drilling, but all that is produced 

in the Lamb and Greybull fields is appropriated for domestic use at 

the towns of Basin and Greybull, which have the distinction of being 

the only towns in Wyoming that use gas as a source of heat and light.

ACKNOWLEDGMENTS.

The authors desire to acknowledge the generous cooperation of the 

officials of the principal oil companies operating in the Big Horn 

Basin. They have furnished logs of wells, and other valuable information. Special thanks are due to John McFayden and M. D. Woolery, 

of the Ohio Oil Co., Homer T. Lamb, of the Bighorn Oil & Gas Co. and 

the Greybull Oil Co., W. L. Walker, of the Valentine interests, T. L. 

Harrison and C. M. Edgett, of the Enalpac Oil & Gas Co., and J. C. 

Tanberg, of the Tanberg Oil Co. Valuable information was furnished 

by Good & Drayton, Nathan and Kendrick Levi, Martin McGrath, 

F. X. Whiting, R. H. George, J. A. Grant, of Thermopolis; Henry M. 

Sherard, Otto Ahrens, and L. E. Cherry, of Greybull; Sam Scoville and
r

FIELD WORK. 13

W. E. Taylor, of Bonanza; and C. A. Fisher, consulting geologist, of 

Denver, Colo. The writers desire especially to express their warm 

appreciation for all favors granted by residents of the Big Horn 

Basin.

The field and office work was done under the supervision of M. R. 

Campbell, whose helpful counsel and advice is hereby acknowledged. 

J. D. Northrop, W. P. Woodring, M. W. Ball, R. H. Wood, E. M. 

Parks, W. B. Emery, and C. J. Hares, of the United States Geological 

Survey, assisted in geologic work in the field. To Millard Massey, 

H. C. Evans, and A. C. Sutherland much credit is due for the efficient 

manner in which they performed camp and other duties.

The report, except those parts whose authorship is specifically indicated under the individual headings, was prepared by the two 

authors jointly.

FIELD WORK.

The field work was of three classes detailed work with topographic 

map, detailed work without topographic map, and reconnaissance 

examination. Practically all field work of Mr. Hewett was of the 

first class, and all done by and under the supervision of the junior 

author was of the second and third classes. Mr. Hewett devoted the 

field seasons of 1911, 1912, and 1913 to geologic work in the Oregon 

Basin, Meeteetse, and Grass Creek basin quadrangles. In this work 

geologic features were located by plane-table and by compass readings 

on numerous prominent objects, the positions of which were determined in making the topographic maps. Mr. Lupton continued the 

work during the field seasons of 1914 and 1915, though without 

topographic base maps, around the south and east sides of the basin 

as far north as Greybull. In this work the anticlines were mapped by 

plane-table methods. The first step in the process was the measurement of a base line a mile or more in length, from which a system of 

triangulation was developed. From these triangulation stations 

detailed mapping was done, and by means of vertical angles the elevations of a sufficient number of adjacent points were determined to 

enable the geologist to draw structure contours on a chosen bed. In 

addition the formations were measured and studied in detail to determine which of them might serve as reservoirs for oil and gas. In 

producing oil fields, samples were collected for analysis so that the oil 

and gas of these fields might be compared with one another and with 

those of other producing areas.

A reconnaissance examination of part of the west side of the basin 

was made in July, 1915, by Mr. Lupton, in company with M. W. Ball 

and Millard Massey. At this tune the wells drilled and drilling in the 

Grass Creek and Little Buffalo Basin fields were located instrumentally 

and many of the records were obtained. In October, 1916, Mr.
14 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

Hewett visited all the fields west of Big Horn River and obtained 

information concerning the results of the drilling that had been done 

for a year.

GEOGRAPHY.

LOCATION.

The Big Horn Basin lies in northwestern Wyoming. (See fig. 1, p. 

11.) It is bounded on the east and northeast by the Big Horn Mountains, on the south by the Bridger and Owl Creek mountains, and on 

the west by the Shoshone Mountains and other ranges that lie east of 

Yellowstone National Park. On the north the basin is open toward 

the plains of southern Montana.

TOPOGRAPHY.

The Big Horn Basin, as the name suggests, is a depression nearly 

surrounded by mountains. It is drained by the tributaries of Big 

Horn River, which enters it through the Wind River canyon on the 

south and flows northward to the junction with Yellowstone River in 

Montana. The most important tributaries of Big Horn River rise in 

the Owl Creek, Shoshone, and Absaroka mountains on the west, and 

among them may be mentioned Owl Creek, Cottonwood Creek, 

Greybull River, and Shoshone River. A few important streams, 

such as No Wood and Shell creeks, rise in the Big Horn Mountains 

on the east. The surface of the basin is trenched by the numerous 

tributaries of Big Horn River and is rolling or hilly except in places 

where extensive terraces border the stream courses.

The anticlines and domes form a belt 15 to 25 miles wide around the 

border of Big Horn Basin. (See PI. I.) On the east and south sides 

of the basin they lie mainly between the outcrop of Wasatch and later 

formations and the mountains that limit the basin. On the "west side 

observations are limited by outcrops of Wasatch and younger formations, including volcanic tuffs, but there is reason for believing that 

the folds persist much farther westward under these-rocks.

ACCESSIBILITY.

The Big Horn Basin is accessible from both the north and the south 

by the Denver-Casper-Billings branch of the Chicago, Burlington & 

Quincy Railroad, completed in 1914, which follows closely the course 

of Big Horn River. By this railroad the anticlines and domes in the 

southern and eastern parts of the basin may be reached with comparative ease, although some of them are 50 miles from the road. 

Many of the anticlines along the west side of the basin may be reached 

most easily from Cody, which is about 65 miles distant from the most 

remote anticline (Fourbear, No. 41, PI. I).
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE I

fas?

X V \wml2fm 77. ':y///A'sY' 'YY <

//.'/Y///-'/ /*. ZY /,

Wt?w&wtt% ^c^%aS^»

 W2^'/_/W-'^//sS.

KirbyJX\HOT SPRINGS CO^ ^Qxx ^^^KIL: ^

 

Wasatch and younger formations """^ /

_ i _i : _ t i - . *.^> ^^

GENERAL MAP OF THE SOUTHERN PART OF BIGHORN BASIN

By D. F. Hewett and Charles T. Lupton
GEOGRAPHY. . 15 

CLIMATE AND VEGETATION.

The climate of the Big Horn Basin is semiarid. Records of temperature and precipitation kept at a number of places in the basin for 

periods of several years show that in general the annual rainfall on the 

border of the basin is 11 to 12 inches and that hi the interior of the 

basin is about 6 inches, and that the ulterior is colder in winter and 

wanner in summer than the border. The greatest variation in temperature between 1898 and 1903 was recorded at Basin, where the 

thermometer has registered a minimum of 51° below zero in February 

and a maximum of 114° above zero in July.

The low winter temperature, as well as the meager rainfall, tend to 

increase the cost of development in an oil or gas region. In Oklahoma, for example, work can be carried on throughout the year, but 

in the Big Horn Basin exceedingly cold weather hinders development 

work for two or three months during the winter, usually in January 

and February and possibly in parts of December and March.

The Big Horn Basin is mainly a grazing region but contains strips 

of irrigable and irrigated lands along the perennial streams. Vegetation is comparatively scanty. Cottonwood trees, which have little 

value except for fuel, border the streams that flow throughout the 

year.- Scrub cedar and a sparse growth of small pines occur here 

and there in the more hilly sections, but timber valuable for lumber 

is scarce. Cactus, sagebrush, and greasewood are common in the dry 

parts of the basin.

WATER.

Water is all important to those who are exploring or planning to 

explore for oil or gas. Hence, in this report, especially in the detailed 

descriptions of the anticlines, particular attention is called to the 

water supply.

The surface-water supply of the Big Horn Basin includes Big Horn 

River, its tributaries, and springs, which occur throughout the basin 

but are most abundant in the border zone adjacent to the mountains. 

Big Horn River and its principal tributaries, Greybull and Shoshone 

rivers, and Owl, No Wood, and Shell creeks, afford an abundant 

supply of good water throughout the year. Many of the other 

tributaries, though perennial in their upper courses for most of the 

year, carry no surface water along their lower courses except in 

periods of flood. The springs that yield good water are most numerous along the edges of the basin; those of the interior yield small 

flows of alkaline water that can be used by stock but that is not good 

for domestic use.

In the absence of a surface supply, water in sufncient quantity for 

use in camp may be obtained by drilling to depths ranging from 100
16 .ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

to 300 feet in the sandstones of the formations that overlie the Cody 

shale, pieferably the Mesaverde, the Meeteetse, and the Lance.

Both the surface and underground water supplies are described in 

the detai ed descriptions of the anticlines and domes.

FUEL.

Fuel is sssential to the development of an oil and gas field, and its 

accessibility materially affects the cost of each well and therefore 

the development of the field. Thus, in the Grass Creek field, Wyo., 

coal is plentiful and sells for about $4 a ton, whereas in Green River 

Desert, Uta,h, coal must be hauled 60 to 80 miles and has sold for as 

much as $20 a ton. This difference in the price of fuel naturally 

affects the number of wells drilled.

In the Big Horn Basin the principal oil fields are not far from the 

outcrops of coal beds, from which fuel can be obtained easily and 

cheaply. The coal beds that have been most extensively developed 

lie in the southern part of the basin in the vicinity of Gebo and Crosby. 

A few local mines ha <;e been opened at places around the edge of the 

basin, but some of these have not been operated recently. The extent 

and the characteristics of the coal have been described by Washburne* and Woodruff.2

Gas has been discovered in commercial quantities in the Greybull, 

Lamb, Grass Creek, Little Buffalo Basin, Oregon Basin, and Byron 

fields, and is being used for fuel and light in camps and towns and 

for drilling purposes. Crude oil is also used as a fuel in drilling in the 

Grass Creek and other fields. Cottonwood, scnib cedar, pine, and 

other trees constitute an additional fuel supply.

GEOLOGY.

STRATIGRAPHY. 

SEQUENCE AND CORRELATION OF THE FORMATIONS.

The formations outcropping in the Big Horn Basin have been examined in part and at different times by several geologists. The following 

table shows the equivalence of the formations noted by the authors 

named and describes them briefly. Fisher,3 as the table indicates, is 

the only author who has made a general examination of all of the 

formations.

1 Washburne, C. W., Coal fields of the northeast side of the Bighorn Basin, Wyo., and of Bridger, Mont.: 

U. S. Geol. Survey Bull. 341, pp. 165-199,1909.

2 Woodruff, E. G., Coal fields of the southwest side of the Bighorn Basin, Wyo.: U. S. Geol. Survey 

Bull. 341, pp. 200-219, 1909; The coal field in the southeastern part of the Bighorn Basin, Wyo.: U. S. 

Geol. Survey Bull. 381, pp. 170-185,1910.

» Fisher, C. A., Geology and water resources of the Bighorn Basin, Wyo.: U.S. Geol. Survey Prof. Paper 

53,1900.
U. 8. GEOLOGICAL SURVEY BULLETIN 658 PLATE II

A. TENSLEEP SANDSTONE ON WEST SIDE OF BROKENBACK ANTICLINE.

. MADISON LIMESTONE IN ANTICLINE IN SHEEP MOUNTAIN CANYON.
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE III

i&ls^y^-;*^ £i .*>! $t1

4. LIMESTONE PART OF THE EMBAR FORMA I ION NEAR HEAD OF NO WOOD CREEK.

*'

£. RED SANDSTONE IN MIUULE PART OF THE CHUGWATER FORMATION ON NO WOOD CREEK 

 ..-.. NEAR TENSLEEP.
Correlation of formations of the Big Horn Basin described in recent reports.

System.

Quaternary.

Tertiary.

Tertiary?

% 

Cretaceous.

Cretaceous?

Jurassic.

Triassic.

Carboniferous.

Ordovician.

Cambrian.

Fisher, 1906: 

U. 8. Geol. Survey 

Prof. Paper 53. 

Entire Big Horn 

Basin.

/ lluvhim. 

Hot-spring deposits. 

Later terrace gravels. 

Early terrace gravels.

Wasatch.

Laramie and associated formations.

Pierre.

Colorado.

Cleverly.

Morrison.

Sundance.

Chugwater.

Embar.

Tensleep.

Amsdcn.

Madison.

Bighorn.

Deadwood.

Washburne, 1909: 

U. S. Geol. Survey 

Bull. 341, p. 167. 

East side of basin.

Wasatch. 

Unconformity 

Fort Union 

Unconforim 

Laramie( ?)

Montana 

group.

Colorado.

Unconform 

Cloverly.

ty(?)

Bearpaw. 

Judith 

River. 

Claggett. 

Eagle.

if *r

Woodruff, 1909: 

U. S. Geol. Survey 

Bull. 341, p. 202. 

West side of basin.

Wasatch. 

Unconformity

Fort Union.

Laramie (?).

UndifferMontana , entiated 

group. Montana. 

Eagle.

Colorado shale.

Cloverly.

Hewett, 1914: 

U. S. Geol. Survey 

Bull. 541, p. 91. 

Shoshone River.

Wasatch.

Fort Union. 

Unconformity?)

Ilo.

Meeteetse.

Gebo.

Upper 

member.

Middle 

Colorado. member.

Lower 

member.

"Cloverly."

Morrison.

Sundance.

Chugwater.

Hintze, 1915: 

Wyoming Geol. Survey 

Bulls. 10 and 11. 

West side of basin.

Fort Union.

Ho.

Meeteetse.

Montana. Eagle.

Pierre.

Basin. 

(Niobrara)

Colorado. 

Benton.

Cloverly.

Lupton, 1916: 

U.S. Geol. Survey 

Bull. 621. 

East side of basin.

Alluvium. 

Terrace gravels.

Undiff erentiated Fort 

Union and Lance.

Montana. 

 (a) 

Colorado.

Mesaverde.

Cody.

Frontier.

Mowry.

Thermopolis.

Cloverly.

Hewett and Lupton, 1917: present report. East and west sides of basin.

Formation.

Volcanic rock.

Wasatch. 

Unconformitv

Fort Union. 

Unconformitv

Lance.

Meeteetse.

Montana. Mesaverde.

Frontier.

Mowry.

Thermopolis.

Cloverly.

Morrison.

Sundance.

Chugwater.

Embar.

Tensleep.

Amsden.

Madison.

Bighorn.

Deadwood.

Thickness 

in feet.

0-50

0-30

(?)

1,300+

2,000-5,600

840-1,800

250-1,400

1,120-1,410

1,900-3,400

494-648

160-375

400-800

110-300

150-580

250-530

700-1,100

250-480

30-230

150-200

600-1,000

150-300

700-900

Character of rocks.

Valley and flood-plain deposits along streams. 

Local deposits of calcareous tufa. 

Gravels and boulders washed from adjacent mountains.

Andesitic tun's and flows on west side of basin.

lied and drab clay; buff and white sandstone with gravel 

lenses. Many areas of badlands around border of basin.

Buff and white gritty sandstone, with drab, red, and 

green clay; lenses of gravel and lenticular beds of coal.

Buff and drab sandstone with drab and green shale. No 

red shale or coal beds.

Soft gray and brown shale; gray and buff sandstone and 

lenticular beds of coal.

Buff and white sandstone, gray and brown shale and lenticular beds of coal near base.

Gray, green, and black shale, with calcareous concretions 

near base, merging with buff sandstone at top. No persistent sharply marked beds.

West side: Seven or more beds of gray and buff sandstone 

with gray and brown shale and bentonite. 

East side: Two to six or more beds of sandstone.

Hard pray shale containing fish scales with lenses of gravel - 

bearing sandstone.

Gray to black shale with one persistent sandstone, the 

Muddy sand of the drillers.

Two beds of massive buff sandstone separated by gray or 

variegated shale. Upper sand is the Greybull.

Purplish and pale greenish-gray shales with sandstones interbedded.

Greenish-gray sandstones and shales with a little limestone 

inter bedded.

"Red Beds": Red sandstones and shales with a thick bed 

of gypsum near top.

Gray limestone, with gray and red sandy shale and gypsum 

interbedded. Limestone very thin on east side of basin.

Massive gray sandstone, containing thin layers of limestone.

Red sandy shales and sandstones, with layers of limestone 

and chert.

Gray massive limestones.

Siliceous gray limestone, very hard and massive.

Sandstone, shale, conglomerate, and limestone.

86133° Bull. 656 17. (To face page 16.)

In U. S. Geol. Survey Bull. 621, through a typographic error, the Montana-Colorado boundary was erroneously drawn at this position.
'-. STBATTGBAPHY. 17 

I

CAKBONlFEKOUS SYSTEM.

MADISON LIMESTONE.

The massive gray Madison limestone ranges in thickness from 600 

to 1,000 feet. Its upper part is more nearly pure than its lower,, 

which is sandy. It contains a Mississippian (lower Carboniferous) 

fauna. In the area shown on Plate I this formation is exposed only 

in Sheep Mountain Canyon, on Big Horn River about 8 miles north 

of Greybjull. Its character is shown on Plate II, B, where only the 

upper 800 feet of the limestone crops out in the walls of the canyon.

AMSDEN FORMATION.

The Amsden formation overlies the Madison and comprises 150 to 

200 feet of limestone, shale, and chert. Its lower 60 to 80 feet is 

bright-red shale and contains layers of limestone and considerable 

chert. A few fossils collected from it indicate that it is of Pennsylvanian (upper Carboniferous) age.

TENSLEEP SANDSTONE. *

The Tensleep sandstone, which conformably overlies the Amsden 

formation, is one of the most prominent formations on the east side 

of the basin. It consists of 30 to 230 feet of yellowish-gray to white 

massive cross-bedded sandstone alternating with beds of limestone. 

(See PL II, A.) The sandstone usually contains water and is believed 

to yield the lowest and strongest flow of water in Catherine No. 2 well 

(No. 11, PL XI, p. 98) near Bonanza.

EMBAR FORMATION.

The term Embar, as used by Darton 1 and Fisher,2 includes a group 

of marine deposits consisting of gray to greenish limestone and chert 

beds lying between the top of the Tensleep sandstone and the base 

of the nonmarine red Chug water formation ("Red Beds")« It ranges 

in thickness from about 250 feet near Embar post office to 480 feet 

at Sheep Mountain Canyon.

Recent investigations in the Wind River Mountains by Blackwelder 

led him to divide the Embar into two formations, the Dinwoody 

above and the Park City below. These units were recognized near 

Thermopolis and near Sheep Mountain (Black) Canyon, at the southern and eastern sides of the Big Horn Basin but were not separable 

over a large part of the area considered in this report. The limestone portion of the Embar is abundantly fossil bearing and is gray 

in color; it bears oil in the Lander field.

i Darton, N. H., Geology of the Bighorn Mountains: U. S. Geol. Survey Prof. Paper 51, pp. 35 and 36, 

1906.

* Fisher, C. A., Geology and water resources of the Bighorn Basin, Wyo.: U. S. Geol. Survey Prof. 

Paper 53, pp. 17 and 18,1900.

86133° Bull. 656 17 2
18 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

In the southern part of the basin the Embar is principally limestone, but farther east and north it grades laterally into the nonmarine 

red sandstone, shale, chert, .and gypsum with minor limestone that 

constitute the lower part of the "Red Beds" or Chugwater forma- 

'tion. (See PL III, A.) This change in character naturally makes 

it difficult to determine the exact limits of the formation.

TRIASSIO SYSTEM. 

CHTTGWATER FORMATION. ^

The Chugwater formation consists of the rocks commonly designated "Red Beds." It is predominantly sandy but includes beds 

of sandstone, shale, gypsum, with a little limestone at the top. (See 

PL III, 5.) It ranges in thickness from 700 to about 1,100 feet. Its 

lower part is apparently less resistant than its upper part and consequently forms valleys. The Chugwater is not known to contain any 

beds of sandstone which would serve as reservoirs for oil and gas 

nor, as the formation is generally sandy, to contain any beds of shale 

that would serve as impervious caps for the sandstones. At one place 

on Red Spring anticline, however, an oil seep was found in this formation. In places the sandstone beds carry water, as in the well (Catherine No. 2, PL XI, p. 98) drilled on Paintrock anticline near Bonanza. 

This well encountered water at not less than five horizons, some of 

which are in this formation.

JURASSIC SYSTEM. 

SUNDANCE FORMATION.

The Sundance is a marine formation of Upper Jurassic age, 250 to 

530 feet in thickness, that consists principally of greenish sandstone, 

shale, and limestone. The thin limestone beds are fossiliferous 

throughout, the formation. In this region the Sundance is predominantly sandy, and some of the sandstones might serve as reservoirs for oil or gas. The formation has, however, been tested 

nowhere in the Big Horn Basin except in the vicinity of Bonanza, 

where the sandstones yield no trace of oil or gas but are believed to 

have yielded some of the water in Catherine No. 2 well.

CRETACEOUS (?) SYSTEM. 

MORRISON FORMATION.

The Morrison formation has been recognized throughout the Big 

Horn Basin. It consists principally of variegated sandstone and 

shale, the latter predominating. It rests with apparent conformity 

on the underlying Sundance formation, and in places its lower part 

is so nearly like the upper part of the Sundance that it is difficult to 

separate the two. The Morrison is characterized by gastroliths or
STRATIGRAPHY. 19

"stomach stones " (very hard, highly polished pebbles of chert, 

quartz, and quartzite, 2 to 4 inches in diameter), which are most 

abundant near the top of the formation. They occur embedded in 

both shale and sandstone, in many places associated with the bones 

of dinosaurs, and serve to identify the formation. The Morrison 

ranges in thickness from about 150 to 580 feet.

Plants collected from the top of the Morrison near Tensleep indicate, according to F. H. Knowlton, 1 that it is of Cretaceous age. The 

fossils were obtained from the same general locality as the leaves 

mentioned by Fisher 2 in his paper on the Kootenai formation.

CRETACEOUS SYSTEM. 

CLOVERLY FORMATION.

The Cloverly formation in places unconformably overlies the Morrison formation. It has an average thickness in the Big Horn Basin 

of about 125 feet. In most places its lower part is a fine white conglomerate or conglomeratic sandstone 15 to 25 feet thick, the pebbles of which are well rounded and are mainly chert. Its middle 

part is reddish sandy shale and thin-bedded sandstone about 75 feet 

thick. This in turn is overlain by 10 to 20 feet of yellowish gray 

sandstone, locally termed the Greybull sand, and here designated the 

Greybull sandstone member of the Cloverly formation,3 from the 

town of Greybull, near which it is typically exposed. It is this sand 

that produces practically all the oil and gas in the Greybull field. 

Its relation to the underlying Morrison formation is shown hi Plate 

IV, A.

Darton 4 believes that this formation corresponds to the Dakota, 

Fuson, and Lakota formations in the Black Hills region. Fisher 5 

collected leaves of Kootenai age from these beds.

THERMOPOLIS SHALE.

The Thermopolis shale conformably overlies the Cloverly formation. It consists mainly of a dark shale 400 to 800 feet thick, sandy 

near its top and base and containing a persistent bed of sandstone 

near its middle. The sandy beds, 100 or more feet thick, near the 

base have been termed "rusty beds" by Washburne,6 and the persistent bed of sandstone near the middle is termed by the drillers the 

"Muddy sand." It is unusually persistent, and being overlain by

1 Knowlton, F. H., Note on a recent discovery of fossil plants in the Morrison formation: Washington 

Acad. Sci. Jour., vol. 6, No. 7, pp. 180,181,1916.

2 Fisher, C. A., Southern extension of the Kootenai and Montana coal-bearing formations in northern 

Montana: Econ. Geology, vol. 3, pp. 84, 85,1908.

»This should not be confused with the " Gray Bull beds," proposed by Granger (Am. Mus. Nat. Hist., 

vol. 33, p. 203,1914) as the name of a faunal zone in the Eocene of this region.

« Darton, N. H., Geology of the Bighorn Mountains: U. S. Geol. Survey Prof. Paper 51, p. 53,1906.

6 Fisher, C. A., op. cit., p. 85. .

«Washburne, C. W., Gas fields of the Bighorn Basin, Wyo.: U. S. Geol. Survey Bull. 340, p. 350,1908.
20 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

shale constitutes a good reservoir for oil and gas. On the east side 

of the basin it contains only a trace of oil and a showing of gas, but 

on the west side it is believed to furnish the strong flow of gas in the 

Oregon Basin field. Near Cody a little oil is yielded by a sand lying 

at approximately the horizon of the Muddy sand. In Plate IV, B, 

the Thermopolis shale is represented by the floor of the valley on 

which the drilling rig stands.

. MOWRY SHALE.

The Mowry shale (PI. IV, B), named from Mowry Creek, on the 

east side of the Big Horn Mountains, is a hard, platy bluish-gray shale 

which conformably overlies the Thermopolis shale. It weathers light 

gray to white and is characterized by large numbers of fish scales. 

Its thickness ranges from about 160 feet near Greybull to about 375 

feet near Thermopolis. In places it contains thin beds of bentonite 

and also beds of sandstone which have been named by drillers the 

Kimball and Octh Louie sands, and which yield most of the oil produced in the Torchlight dome near Basin. The presence of the fish 

scales suggests that at least part of the oil contained in the formation 

originated there.

FRONTIER FORMATION.

The Frontier formation (PI. V, B] conformably overlies the Mowry 

shale, and includes from about 500 to about 650 feet of sandstones and 

interbedded shale. Near Greybull only two beds of sandstone are 

present, but in the southern and western parts of the basin there are 

five or six beds. In the vicinity of the town of Basin the two principal sandstones have been named the Torchlight and Peay sandstone 

members. On the west and south sides of the basin the top sandstone of the Frontier is here called Torchlight (?) sandstone member, 

as it is believed to be the equivalent of the Torchlight on the east side 

of the basin. The outcrop of Peay sandstone near Greybull is shown 

in Plate V, A. The sands of the Frontier formation contain one or 

more thin beds of fine conglomerate, the most persistent being at the 

top of the Torchlight sand or base of the Cody shale. In places this 

conglomerate is unconsolidated and is 1 or 2 inches thick, but elsewhere it is consolidated and attains a maximum thickness of 7 feet. 

The lower of the two sands, the Peay, yields all the gas produced in 

the Lamb-anticline. The sandstones of the formation also yield oil 

and gas in the Grass Creek and Little Buffalo fields.

The sandstone beds of the Frontier formation, so far as development work has progressed, appear to be the most important reservoirs of oil and gas in the Big Horn Basin, and it is believed that future 

development will confirm this conclusion.
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE IV

A. UNCONFORMABLE CONTACT BETWEEN WHITE SANDSTONE OF THE CLOVERLY FORMATION 

AND VARIEGATED SHALE OF THE MORRISON FORMATION NEAR TENSLEEP.

B. THERMOPOLIS AND MOWRY SHALES NEAR BONANZA. 

Standard drilling rig in foreground.
U. 8. GEOLOGICAL SURVEY BULLETIN 656 PLATE V

A. PEAY SANDSTONE MEMBER OF THE FRONTIER FORMATION ON EAST SIDE OF BIG HORN

RIVER NEAR GREYBULL.

:_S\

B. FRONTIER FORMATION IN LYSITE MOUNTAIN ANTICLINE.
STRATIGRAPHY.

The name Frontier in its type locality in southwestern Wyoming l . 

is applied to a group of sandstone, shale, tod coal beds 2,200 to 2,600 

feet thick. In Carbon County, Wyo., about 200 miles farther east, 

the formation ranges from 400 to 800 feet thick and has no coal beds. 

In the Big Horn Basin beds of sandstone and shale occur at the same 

stratigraphic position and hence have been given the same name.

As this formation probably contains most of the oil and gas in the 

Big Horn Basin, a number of detailed sections are given in order to 

show the changes its character undergoes from place to place.

Section of Frontier formation on west side of Sheep Mountain, in T. 53 N., R. 94 W.,

near Greybull, Wyo.

Sandstone (Torchlight), gray, soft, cross-bedded, conglomeratic at Feet.

top; pebbles mainly chert................................... 20+

Shales, gray, drab, and yellowish, contains a few thin sandstone

beds....................................................... 250

Sandstone (Peay):

Sandstone, yellowish, soft at base; dark gray, weathering very

rusty brown, harder, and more concretionary in middle;

and white to gray, massive, cross-bedded in upper part... 50 

Shale, very sandy, with some beds of sandstone............. 40

Sandstone, gray, weathering brown, soft, shaly............. 10

Shale, gray, drab, and yellowish, sandy.................... 25

Sandstone, yellowish, soft, shaly............................ 6

401+

Section of Frontier formation in southeastern part of T. 49 N., R. 91 W., near Bonanza,

Wyo.

Sandstone (Torchlight), yellowish gray, soft, slightly conglomer- Feet, 

atic at top.................................................. 33

Sandstone, gray to white, contains yellowish-brown, concretionary, slightly conglomeratic lenses............................ 10

Sandstone, dark gray and brown, carbonaceous, soft, grades into 

clay........................................................ 20

Clay, sandy, gray.............................................. 85

Shale, gray and drab, sandy................................... 100

Sandstone and shale, most of sandstone in upper half; gray, weathers brown; contains a thin bed of shale intermixed with small 

chert pebbles; shale weathers to light clay.................... 45

Sandstone (Peay):

Sandstone, yellowish gray, slightly conglomeratic at top, medium bedded, contains a few thin beds of gray shale...... 50

Sandstone and sandy shale alternating..................... 17

Sandstone, gray, weathers brown, medium bedded.......... 100

Shale, contains thin beds of bentonite...................... 30

Bentonite................................................ 4

Shale, grayish brown, soft.................................. 55

549

i Veatch, A. C., Geography and geology of a portion of southwestern Wyoming, with special reference to 

coal and oil: U. S. Geol. Survey Prof. Paper 56, pp. 65-69,1907.
2 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

Section of Frontier formation in northeastern part of T. 44 N., R. 88 W., near Bigtrails,

Wyo.

Sandstone (Torchlight?), brown, massive at top, thin bedded Ft. in. 

at bottom.............................................. 15 0

Shale, dark, sandy, contains a few thin beds of sandstone.... 150 0

Sandstone................................................ 2 0

Shale..................................................... 85 0

Sandstone, buff, fine grained, massive...................... 22 0

Shale, upper half gray and buff; lower half dark, contains ferruginous masses......................................... 110 0

Sandstone, buff and brown, thin bedded at base, massive at 

top; upper 2 feet contains many black, red, and white chert 

pebbles ranging in size from sand grains to an inch in diameter.................................................. 80 0

Shale, dark, sandy, contains a few lenses of sandstone....... 19 0

Sandstone, pepper and salt appearance, coarse.............. 6

Shale, dark, sandy, contains ferruginous masses that weather 

blackish red............................................ 20 0

Shale, black, fissile....................................... 5 0

Sandstone, gray, iipper part stained greenish yellow, thin 

bedded, huge ripple marks at top........................ 13 6

Shale, dark, sandy........................................ 30 0

Shale, light gray to blue, resistant......................... 13 0

Shale, dark, fissile, contains fish remains.................... 23 0

Sandstone................................................ 1 6

Shale, dark, fissile......................................... 30 0

Bentonite................................................ 6

620 0

Section of Frontier formation along Big Horn River, in T.43N.,R. 94 W., near Thermopolis, Wyo.

Sandstone (Torchlight?), brown and gray, soft, shaly, some peb- Feet,

bles at top.................................................. 48

Shale, light, bentonitic....................................... 64

Sandstone, gray.............................................. 16

Shale......................................................... 50

Sandstone.................................................... 30

Sandstone, gray.............................................. 20

Shale, concealed............................................. 75

Sandstone, gray.............................................. 10

Concealed, probably shale..................................... 55

Sandstone, gray massive, resistant; forms ridge................. 15

Shale, partly concealed........................................ 25

Sandstone, brown, massive.......................... i.......... 10

Shale, brownish............................................... 5

Sandstone, brown, thin bedded and shaly....................... 15

Shale, gray, contains thin beds of sandstone near top............ 110

Sandstone, gray, massive....................................... 20

Sandstone, dark, thin bedded................................. 10

Shale, bluish, sandy.......................................... 25

Bentonite.................................................... 5

Shale, dark...... ~~ - ..................................... 40

648
STRATIGRAPHY. 23

Section of Frontier formation on Shoshone River in T. 53 N., R. 101 W., near Cody, Wyo.

Sandstone (Torchlight?), buff, separated into three benches by 

thin brown shale bands; upper and lower benches contain chert Feet, 

pebbles, the largest half an inch in diameter.................. 24

Sandstone, buff to gray, shaly.................................. 60

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

Bentonite.................................................... 8

Shale, brown................................................. 5

Sandstone, buff................................................ 6

Bentonite.................................................... ' 6

Shale, brown, with 4 inches of coal............................. 3

Sand, brown, shaly........................................... 8

Shale, brown, with two thin coal beds........................... 2

Shale, dark................................................... 13

Sandstone, buff................................................ 3

Shale, sandy.................................................. 30

Sandstone, buff................................................ 6

Shale, sandy.................................................. 55

Sandstone, drab, separable into four massive benches by thin shale 

layers; second bench from the top contains black chert pebbles 

three-fourths of an inch in diameter........................... 40

Shale, sandy.................................................. 32

Sandstone, buff, thin bedded................................... 18

Shale, sandy.................................................. 22

Sandstone, buff, thin bedded................................... 12

Shale...:..................................................... 16

Sandstone, buff................................................ 8

Shale......................................................... 16

Sandstone, buff................................................ 40

Shale.....'.................................................... 24

Sandstone, buff, thin bedded, containing nonpersistent zones of 

chert pebbles as much as 3 inches thick near the top and a highly 

persistent zone 6 inches thick near the middle; the pebbles 

measure from three-fourths of an inch to 2 inches; fragments of 

bone and bivalve shells are common.......................... 36

494

Section of Frontier formation on the east side of Wood River in sec. 15, T. 47 N., R. 101 W.,

near Sunshine, Wyo.

Sandstone (Torchlight?), buff, with two thin persistent zones of Feet,

chert pebbles................................................ 67

Shale, black and brown......................................... 7

Sandstone, buff, thin bedded..................................... 13

Shale, with some sandy zones.................................. 151

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

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

Shale......................................................... 36

Sandstone, buff................................................ 14

Shale......................................................... 12

Sandstone, buff................................................ 48

Shale......................................................... 106

Sandstone, buff................................................ 23

 503
24 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

Section of Frontier formation on the north limb of the .Cottonwood anticline south of

Cottonwood Creek in see. 11, T. 44 N., R. 98 W.

Feet.

Sandstone (Torchlight?), buff to white, persistent............... 45

Shale, sandy, with several nonpersistent thin beds of sandstone.. 40

Sandstone, buff................................................ 18

Shale, sandy, gray and black................................... 40

Sandstone, thin bedded....................................... 10

Sandstone, shaly, buff to white................................. 30

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

Bentonite.................................................... 1

Sandstone, white............................................. 1

Bentonite..................................................... 3

Shale, sandy.................................................. 10

Sandstone, buff to gray, persistent; forms ridge................. 18

Shale, sandy.................................................. 20

Sandstone, local lens.......................................... 2

Shale, sandy, gray............................................. 18

Sandstone,local lens.......................................... 2

Shale, sandy.................................................. 6

Sandstone, buff, persistent..................................... 3

Shale, gray; weathers light.................................... 18

Sandstone, shaly.............................................. 10

. Shale, gray; weathers white; resembles Mowry shale............. 25

Shale, dark gray, easily disintegrated.......................... 10

Sandstone, gray to white, persistent; forms ridge................ 42

373

CODY SHALE.

x

The name Cody shale was recently applied by Lupton 1 to the 

group of shale and shaly sandstone beds that overlie the Frontier 

formation near Basin, Wyo. The unit occupies the same position 

in the section as that mapped by Fisher 2 as the Pierre shale, as that 

described by Hewett 3 as the upper shale member of the Colorado 

formation on Shoshone River, and as the Basin and Pierre formations as described by Hintze.4 In contrast with the underlying 

Frontier formation and the overlying Mesaverde formation the Cody 

shale weathers readily and therefore underlies broad rolling plains or 

valleys limited by escarpments of the higher formation. For this 

reason, the knowledge of the shale is derived from exposures of parts 

of the unit in small badlands areas or stream valleys.

The thickness ranges from a minimum of 1,900 feet on the south 

side of the Cottonwood anticline to a maximum of 3,400 feet on the 

west side of the North Sunshine anticline. In general, the differences in the measured thickness appear to result from folding, as 

well as from conditions of deposition. Measurements of thickness

i Lupton, C. T., Oil and gas near Basin, Big Horn County, Wyo.: U. S. Geol. Survey Bull. 621, p. 171,1916. 

* Fisher, C. A., op. cit., p. 30.

« Hewett, D. F., The Shoshone River section, Wyo.: U. S. Geol. Survey Bull. 541, p. 98,1914. 

«Hintze, F. F., jr., The Basin and Greybull oil and gas fields, Wyo.: Wyoming Geol. Survey Bull. 10, 

pp. 24, 27,1915.
STEATIGEAPHY. 25

on the limbs of folds are commonly greater on the steep than on the 

flat limbs. The available data indicate that on the west side of the 

basin the thickness of the shale increases from 2,150 feet in the latitude of Cody to nearly 3,000 feet on the Enos Creek anticline, then 

decreases to about 2,000 feet on Cottonwood Creek. On the east 

side of the basin the thickness is 300 to 600 feet greater than on the 

west side. It apparently increases to about 3,000 feet on Big' Horn 

Kiver near Lucerne, at the south end of the basin, and remains constant along the south and east sides as far as Bonanza. Northwest 

from Bonanza it thickens to about 3,350 feet at the south side of the 

Torchlight dome, and then thins to about 2,600 feet on Greybull 

River, west of Greybull.

The character of the Cody shale and higher formations will not be 

presented in detail. The lower two-thirds of the formation is largely 

shale, predominantly dark gray but locally light gray, brown, and 

black. This part includes poorly defined interbedded lenses of finegrained gray and brownish sandstone and in some sections considerable green glauconite.

Many marine fossils have been found in the shale 200 to 500 feet 

above the base, but a larger number are obtained from rounded calcareous concretions which occur sporadically in the shale. These 

fossils are reported by T. W. Stanton to be characteristic of the Colorado group. There is no sharp limit between the lower shaly part of 

the formation and the upper, which is largely thin-bedded buff sandstones. Lenses of resistant sandstone 20 to 45 feet thick, which occur 

from 100 to 400 feet below the top of the formation, are more conspicuous in basins south of the Oregon Basin. On the south and east sides 

of the Big Horn Basin the Cody shale consists almost entirely of 

shale with lenses of sandstone near the base and more persistent 

concretionary beds near the top.

Several collections of marine fossils from a zone about 1,000 feet 

thick at the top .of the formation are reported by T. W. Stanton to 

belong to the Montana group. 1 Other collections from the upper 

sandy part include shark teeth but are not diagnostic.

At no place in the Big Horn Basin is the Cody shale known to contain oil or gas in commercial quantity. It is possible that these 

substances may be found in the sandstone where conditions are 

favorable.

MESAVERDE FORMATION.

The Mesaverde formation is a group, of massive resistant sandstones 

with thin layers of interbedded coal and shale that overlies the Cody 

shale and forms prominent escarpments in many parts of the Big 

Horn Basin. The name was first applied to a group of coal-bearing

i Lupton, C. T., op. cit., p. 172.
26 ANTICLINES IN SOUTHERN PART OF BIG HORN BASlN, WYO.

rocks about 1,000 feet thick that overlies the marine Mancos shale 

and is in turn overlain by the marine Lewis shale in southwestern 

Colorado.1 Field work by members of .the United States Geological 

Survey has shown that a similar coal-bearing group of rocks underlain and overlain by marine shale persists through western Colorado 

and southwestern and central Wyoming, and fossils have warranted 

the correlation of the successive formations with the Mancos, Mesaverde, and Lewis formations, except that in central Wyoming the 

lower marine shale is known as the Steele shale, as it there represents 

only the upper part of the Mancos, the rest of the Mancos being 

represented by several older formations. In describing the coal 

fields of the Wind River Basin in central Wyoming, Woodruff and 

Winchester 2 recognized a group of coal-bearing beds 1,000 to 3,000 

feet thick, overlying a thick shale, the lower part of which contains 

marine fossils of Colorado age and the upper part marine fossils of 

Montana age. The shale was correlated with the Mancos shale and 

the coal-bearing beds with the Mesaverde formation, although the 

marine Lewis shale known to the east and south was not known to 

be present. The character of the Upper Cretaceous beds of the west 

side of the Big Horn Basin arid the northwest corner of the Wind 

River Basin are strikingly similar, and, although the overlying marine 

Lewis shale is absent, the use of the term Mesaverde is warranted.

On the west side of the Big Horn Basin the lower part of the formation is characterized by two beds of massive buff sandstone 40 

to 60 feet thick, between which there are one or more lenticular but 

locally important beds of coal. The lowermost of these two sandstones was first identified by Washburne 3 as the Eagle sandstone 

but has been shown by recent work to lie considerably higher in the 

section than the type Eagle of northern Montana. (See PI. VI, A.) 

The coal beds of this part of the formation are not important east of 

Big Horn River; the higher beds are locally thick enough to warrant 

mining, but the separate beds are not persistent .over large areas, 

and according to the evidence on the west side of the Big Horn 

Basin, the thickest beds become thinner and disappear toward the 

southwest and are succeeded by overlapping higher beds. The 

upper limit of the formation is the top of a group of gray to white 

beds of sandstone 200 to 400 feet thick. In contrast with the sandstone of the overlying Meeteetse and Lance formations, that of the 

Mesaverde is hard and resistant, so that the beds near the base form 

prominent escarpments over the softer Cody shale and the beds at

i Holmes, W. H., U. S. Geol. and Geog. Survey Terr. Ninth Ann. Rept., p. 244,1875.

'Woodruff, E. G., and Winchester, D. E., Coal fields of the Wind River region: U. S. Geol. Survey 

Bull. 471, p. 522,1912.

3 Washburne, C. W., Coal fields of the'northeast sideof theBighorn Basin, Wyo., and of Bridger, Mont.: 

U. S. Geol. Survey Bull. 341, pp. 167-168,1909.
BULLETIN 656 PLATE VI

A. LOWER SANDSTONE (FORMERLY CALLED EAGLE) OF MESAVERDE FORMATION NEAR

ZIMMERMAN BUTTE.

J3. ANGULAR UNCONFORMITY (REPRESENTED BY HEAVY LINE) BETWEEN THE FORT UNION 

AND LANCE FORMATIONS ON DRY CREEK NEAR GREYBULL.
STRATIGRAPHY. 27

the top form persistent ridges that limit the valleys carved in the 

Meeteetse beds.

The thickness of the formation ranges from a maximum of 1,410 

feet north of the Cottonwood anticline to 1,120 feet on Shoshone 

River, and the average thickness throughout the Big Horn Basin 

is about 1,200 feet. The age of the formation is fixed by the identification by F. H. Knowlton of fossil leaves from several horizons.

MEETEETSE FORMATION.

The Meeteetse formation includes the beds of soft gray shale, 

sandstone, and coal which overlie the Mesaverde formation. Where 

the beds dip more than 10° or 15° narrow valleys follow the outcrop 

of the formation, but where the dip is not so steep badlands are common. On the west side of the Big Horn Basin the thickness ranges 

from a maximum of 1,240 feet in T. 50 N., R. 101 W., to 750 feet 

in T. 46 N., R. 97 W., east of the Grass Creek basin and is separable 

into two nearly equal parts, a lower dominantly sandy part with 

shale but no coal and an upper part, which contains a number of 

beds of brown shale and of coal, some of which are locally mined. 

Throughout this part of the basin the upper limit of the formation 

is the base of the first massive sandstone that overlies the uppermost coal bed. Although the formation has yielded many leaves 

and plant remains which are regarded by F. H. Knowlton as Montana 

in age no vertebrate or invertebrate fossils have yet been found in it.

It is believed to include the equivalent of the Bearpaw shale 

although no marine fossils have been found in it in the area under 

consideration. Washburne 1 reports marine fossils from shale at the 

horizon of the Bearpaw formation near Elk Basin anticline, in the 

northwestern part of the Big Horn Basin.

TERTIARY (?) SYSTEM. 

LANCE FORMATION.

The name Lance is applied to the beds included by Hewett in 

the "Ilo formation" along Shoshone River 2 and to a similar group 

of beds on the east side of the Big Horn Basin which have yielded 

enough vertebrate fossils to warrant correlation with the Lance formation of eastern Wyoming. The base is the first massive sandstone that overlies the coal-bearing part of the Meeteetse formation 

west of Big Horn River and the shale east of the river. The upper 

limit of the formation is the base of a conglomerate or gravel-bearing 

gritty sandstone of the Fort Union formation that has been traced

' Washburae, C. W., Coal fields of the northeast side of the Bighorn Basin, Wyo., and of Brldger, Mont.: 

U. S. Geol. Survey Bull. 341, p. 169,1909. 

8 Hewett, D. F., op. cit., p. 103.
28 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

over a large part of the basin from two areas in which it is unconformable on the Lance beds. One of these areas lies in the easteni 

part of T. 50 N., R. 100 W., east of the Oregon Basin, and the other 

in the eastern part of Tps. 51 and 52 N., R. 94 W., near the mouth 

of Greybull River. This unconformity also is well exposed in Dry 

Creek. (See PI. VI, £.)

The formation is largely soft drab and gray massive sandstone 

with shale. It contains no coal on the west side of the Big Horn 

Basin, but in the vicinity of Greybull and farther southeast it includes 

lenticular beds that are locally mined. Its correlation with the 

Lance formation is based on the identification of Triceratops bones 

by C. W. Gilmore. On the west side of the basin its thickness 

ranges from 1,790 feet on Shoshone River to 840 feet on Prospect 

Creek, 50 miles south, and on the east side of the basin it averages 

about 1,800 feet.

Although this formation is usually classed in the Tertiary (?) system the striking unconformity at its top in the Big Horn Basin 

inclines the writers to believe that it is more properly assignable to 

the Cretaceous.

TERTIARY SYSTEM. 

FORT UNION FORMATION.

The recognition of the Fort Union formation is based on the identification by F. H. Knowlton of many species of fossil leaves. In 

comparison with most of the regions in which it is known the formation in the Big Horn Basin has yielded few invertebrate fossils. 

On the west side of the Big Horn Basin the lowest sandstone of the 

Fort Union may be traced from sec. 29, T. 50 N., R. 100 W., where 

it rests on the Lance formation 1,360 feet thick, to sec. 2, T. 50 N., 

R. 100 W., where it rests on the lower part of the Meeteetse formation, which contains no coal. The maximum discordance in dip 

occurs in the latter locality, where the Meeteetse beds dip 22° E. 

and the Fort Union sandstone 9° E. On the east side of the basin 

it may be traced southward from Sheep Mountain to the vicinity of 

Tensleep Butte, where the Fort Union and Lance are overlapped by 

the Wasatch. Southward from this locality the unconformity was 

traced for 10 miles or more. Along the south side of the basin east 

of Big Horn River no evidence of an unconformity was observed. 

The Fort Union is overlain unconformably by the Wasatch and 

younger formations; The best exposures are found where streams 

have cut valleys across the strike of the beds, as along Greybull 

River and in the "Hole in the Ground" in T. 48 N., R. 99 W. The 

maximum thickness of the Fort Union formation, 5,592 feet, was 

measured in the Shoshone Canyon and in the east half of T. 51 N., 

R. 101 W. East of the Oregon Basin it is completely overlapped 

by beds of the Wasatch formation.
STBATIGKAPHY. 29

On. the east side of the Big Horn Basin the Fort Union formation 

ranges in thickness from about 1,200 feet near Kirby to about 2,000 

feet on Greybull River, about 4 miles above its mouth.

The formation is largely composed of white, buff, and drab sandstones with gray, olive, and red shale. On the west side of the 

basin, the basal bed is generally conglomeratic and there are also 

several higher persistent beds of conglomerate. The pebbles of the 

conglomerate are largely white and red quartzite, but there are also 

cherts with Carboniferous and Permian fossils, silicified wood that 

resembles the variety found in the Meeteetse formation, and pale 

red andesite. Granite pebbles are rare and limestone and vein 

quartz have never been found. The formation contains important 

but lenticular beds of coal at 100 to 150 and at 480 feet above the 

base on the west side of the basin. On the east and south sides of 

the basin no coal of economic importance is known to be present. 

Thin beds of coal and carbonaceous shale are known near the top 

of the formation on Antelope Creek, about 3 miles southwest of the 

town of Basin.

Although the beds of the Fort Union formation are involved in the 

folds the relations to the underlying beds show that a slight amount 

of local folding took place when the basal beds were laid down. The 

persistent occurrence of water-worn fragments of silicified wood suggests that some of the sediment was derived from the Meeteetse 

formation.

WASATCH AND YOUNGER FORMATIONS.

In this report the name "Wasatch" is applied to a group of beds 

that are separated from the underlying Fort Union and older formations by an unconformity commonly recognizable by a discordance 

in dip and that are covered by the volcanic tuffs and flows adjacent 

to the Shoshone Mountains. As thus defined, the formation includes 

beds that attain a probable maximum thickness of 2,500 feet * in the 

vicinity of McCulloch Peak and contain the faunal zones recently 

given the names Greybull, Lysite, Lost Cabin, and Tatman by Sinclair and Granger.2

In areas of pronounced unconformity the basal beds contain lenses 

of conglomerate and gravel composed of the rock types represented 

in the Fort Union formation and of limestone and pale-red granite. 

In the matrix of the gravel angular feldspar is an important constituent. The higher beds contain gritty calcareous sandstone and numerous alternations of drab, olive, and red sandy clay. Many streams 

of the central part of the basin rise in badlands, the walls of which

1 Fisher, C. A., op. cit., p. 33.

2 Sinclair, W. J., and Granger, Walter, Notes on the Tertiary deposits of the Bighorn Basin: Am. Mus. 

Nat. Hist. Bull., vol. 31, p. 57, 1912.

Granger, Walter, On the names of lower Eocene faunal horizons of Wyoming and New Mexico: Am. 

Mus. Nat. Hist. Bull., vol. 33, p. 201,1914.
30 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

show many such alternations of somber and highly colored beds. A 

very striking feature of the formation is the lenticular character of 

each of the beds, the succession in one badland area rarely being the 

same as that in an adjacent area. The clay beds of the badlands 

areas have yielded bones of a number of mammalian vertebrates, 

from which, on the basis of determinations by C. W. Gilmore, the 

age of the formation is established. Locally, thin beds of brown 

shale yield leaves and the variegated clays yield invertebrate fossils, 

but these are uncommon. The formation does not contain coal in 

the basin.

STRUCTURE. 

DEFINITIONS OF STRUCTURAL TERMS.

In general, the term "anticline" is applied to an upfold in bedded 

rocks and the related term "syncline" to a downfold. Horizontal 

folds that are beveled by a surface which is approximately horizontal show nearly parallel outcrops of the beds of rock. In an anticline the oldest beds those that were originally the most deeply 

buried lie in the middle and are bordered on both sides by belts of 

younger rocks the oldest nearest the middle which dip outward 

from the central older rocks. In a syncline the youngest rocks form 

the middle belt and are bordered by belts of older rocks, which dip 

inward toward the central and younger rocks. Some anticlines and 

synclines show on the surface as exceptionally regular parallel belts 

of rock beds 50 to 100 miles long. Most folds, however, are shorter, 

and the outcrops of the beds that form them appear at the surface as 

roughly parallel elliptical belts. Where these belts are nearly circular, or slightly elliptical, and the rocks dip away from the center, the 

fold is called a dome.

As some of the terms that have been applied to parts of folds have 

been very loosely used and as some parts have never been named, it 

seems desirable to redefine some of these terms and to introduce new 

names for parts that have heretofore had no specific names. The 

term "axis" is in common use, but its usage is variable and not at all 

exact. It has been applied to three distinct parts of a fold (1) the 

line on the surface of the ground which separates opposed dips, (2) 

the highest part of a chosen bed in an anticline and the lowest part 

of the bed in a syncline, and (3) the line of intersection of the axial 

plane or axial surface of a fold with a particular stratum. In some 

folds these lines will coincide if they are viewed from a point high 

above the surface of the ground; but in other folds, such as most of 

those in the Big Horn Basin, if thus viewed, they may appear to be 

several hundred feet apart. It is important, therefore, to the oil 

operator and prospector that the three lines be so clearly discrimi-
STRUCTURE. 31

nated that they may be easily recognized in the field and that the 

terms used to designate them be clearly understood.

The word "axis" should be used in only one of the three meanings 

given above, and it is proposed to limit it to the third meaning. 

Other names will be suggested for meanings 1 and 2. The definition of "axis" then is, the line marking the intersection of the axial 

plane or axial surface of a fold with any particular stratum. The 

"axial plane" of a fold has been defined by Willis 1 as the plane that 

bisects the angle between its limbs. (See diagram 1, fig. 2, p. 35.) 

For the other two lines to which the term "axis" has been applied, 

new names are proposed. The term "crest trace" is proposed for 

.that line on the surface of-a folded stratum which passes through 

the highest points of all vertical sections that cut the surface at right 

angles to the trend of the fold. If the length of an anticline is almost 

equal to its breadth, the fold becomes a dome and its crest trace is 

short. The term "crest line" is proposed for that line on the surface of the ground from which the beds dip away in opposite directions. If a given bed has the same dip on both limbs of an 

anticline the horizontal position of the crest line will coincide with 

both the axis and the crest trace of the bed. It seems desirable that 

the term "crest" be left free for application generally to the high 

part of a folded bed and not restricted to any particular line.

Where the beds in a fold are strictly parallel (see fig. 2) the crest 

trace of a buried bed lies vertically beneath the crest line on the 

surface. On the other hand, where the beds are parts of "similar" 

folds, such as are probably formed by the oil-bearing sands of most 

of the anticlines of the Big Horn Basin, the crest trace of a buried 

bed does not lie vertically beneath the crest line but is offset in the 

direction of the flat limb of the fold.

In the simplest type of anticline, the dip of the beds increases 

from zero at the crest to the point of its maximum inclination, and 

beyond this point it decreases again to zero at the axis of the syncline or at the point where the anticline merges into flat-lying beds. 

In many anticlines, however, the dip from the crest first increases, 

then decreases for a short distance, and then increases again. That 

part of the fold in which the dip thus decreases is called a structural 

terrace. (See cross section of Cottonwood anticline, PL XXII, p. 150.) 

Many of the anticlines of the Big Horn Basin are unsymmetrical 

that is, the maximum dip of one limb is much greater than the 

maximum dip of the other.

According to the definitions proposed the axis and the crest trace 

are lines on folded beds, and there can be as many axes and crest 

traces as there are beds. Therefore, if these definitions are accepted

i Willis, Bailoy, The mechanics of Appalachian structure: U. S. Geol. Survey Thirteenth Ann. Kept., 

pt. 2, p. 220,1892.
32 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

it will be appropriate to refer to the axis or to the crest trace of a 

folded bed but not to the axis of an anticline or fold. The axis of a 

folded bed can, of course, rarely be determined, as it can be discovered only by means of cross sections of the bed. The crest trace 

can be determined only by making a structure-contour map of the 

bed. The crest line, however, being a line on the surface of the 

ground, may be drawn by making a number of observations of dip. 

In discussing many regions in which the folded rocks yield oil, 

definitions so precise as those here suggested are not necessary. 

Where the dip of the strata in the limbs of the folds is low and almost 

uniform the horizontal position of the axis, the crest trace, and the 

crest line coincide, or so nearly coincide -that they need not be discriminated, but where the dip differs greatly from place to place the 

horizontal projection of the crest trace of one bed may be several 

hundred feet distant from that of a bed a thousand feet deeper, and 

neither may coincide with the projection of the crest line. As oil 

and gas tend to occur along the high part or crest of certain folded 

sandstones it is necessary, in regions where the difference in dip on 

the limbs is great, to place exploratory holes in positions where they 

may strike the crest traces of the productive sands. Folds of this 

type are common in the Big Horn Basin, and drill holes that may 

give conclusive results should be located, not necessarily along the 

crest lines but in positions where they may strike the crest traces of 

the most productive buried sand. In order to place them in proper 

positions careful studies of all available field data may be necessary 

in advance of drilling.

GENERAL STRUCTURE OF THE BIG HORN BASIN.

The important general features of the structure of the Big Horn 

Basin and the surrounding mountains have been described by 

Fisher.1 Structurally the Big Horn Basin is a depression bounded 

on all sides except the north by prominent upfolds which form the 

mountains that surround it. The structure of the Cretaceous and 

older rocks along the mountains on the west and southwest sides of 

the basin is largely concealed by a thick cover of approximately horizontal volcanic tuffs and lava flows of Tertiary age. The difference 

in elevation of the pre-Cambrian surface restored over Cloud Peak, 

which has an elevation of 13,163 feet, and the same surface under 

the trough of the basin amounts to about 27,000 feet and gives a 

measure of the deformation that produced the basin.

On the basis of structure the Big Horn Basin may be separated 

into two parts (see PL I), an inner or central part in which the surface 

rocks belonging to the Wasatch and younger formations are almost

i Fisher, C. A., op. cit., p. 36.
STRUCTURE. 33

horizontal, and an outer or border part adjacent to the mountains 

in which the beds older than the Wasatch are thrown into a number 

of pronounced but comparatively small folds. The Wasatch and 

younger beds of the central part are only locally horizontal, however, 

for they dip slightly toward a fairly defined middle trough trending 

roughly N. 40° W., and there are also several minor, approximately 

parallel, less extensive folds. One such minor syncline trends southeast in the southwest part of T. 51 N., R. 99 W. The Neiber anticline (No. 29, PL I; see also PI. XX, p. 140) in the southern part of 

the basin is perhaps the most conspicuous fold developed in the 

Wasatch formation. The dips of the Wasatch beds are steepest on 

the basinward limb of the border belt of folds. Locally, on the east 

limb of the Oregon Basin domes, the dip is as great as 33°, but the 

usual range is 5° to 15°, and in the central part of the basin it rarely 

exceeds 3°.

The border belt of folds is not sharply separable from the upfolds 

that coincide with the mountains (Big Horn, Bridger, Owl Creek, 

and others) around the basin, because transitions in size may be 

found from the smallest folds, most of which lie nearest the middle 

of the basin, to the largest, most of which occur near the mountains. 

Along the border belt of folds the dip of the beds commonly ranges 

from 10° to 45° and in many places from 45° to 75°.

Local but important unconformities (see p. 28) are shown where, 

east of the Oregon Basin, the beds of the Fort Union formation rest 

upon the middle part of the Meeteetse formation, and west of Greybull along Dry Creek and Greybull River where the Fort Union 

formation shows a striking discordance in dip with older beds whose 

age has not been definitely determined. These unconformities show 

that some of the folding in the border belt took place before the 

deposition of the Fort Union formation. The border relations of the 

Wasatch and the younger formations show that further folding took 

place before the beginning of the Wasatch deposition but was not 

completed until after an undetermined but probably large part of 

this formation had been laid down. There have been minor folding 

and faulting since that time, but the folding has been along axes 

that only locally coincide with those of the earlier epochs.

STEUCTURE OF THE ANTICLINES AND DOMES.

The present report describes most of the anticlines and domes of 

the border belt of the basiii south of the latitude of Cody and Greybull. These folds range from simple anticlines such as the Thermopolis anticline (No. 27, PL I; see also PL XXI, p. 146) with sharply 

defined crest lines that may be followed for 25 miles or more to domes 

such as Little Grass Creek dome (No. 36, PL I; see also PL XXIV, 

86133° Bull. 656 17 3«
34 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

p. 160) almost circular in outline and therefore without well-defined 

crest lines. One structure, the Half Moon anticline (No. 42, PI. I; 

see also PI. XXIX, p. 178), may be regarded as half of a simple anticline broken by a fault parallel to the crest line. As the extent of 

an anticline, slope of the limbs, and age of the oldest formations that 

outcrop along the crest indicate the depth to which a fold probably 

persists, there is little doubt that some of the larger anticlines, such 

'as Sheep Mountain (No. 1), Thermopolis (No. 27), and perhaps 

Cottohwood (No. 32), involve pre-Cambrian rocks^ Others, such as 

Shoshone (No. 48), Sunshine (No. 40), Waugh (No. 31), Lake Creek 

(No. 22), Bonanza (No. 11), and Manderson (No. 10) are so narrow 

and have limbs so steep that although they may go down to the 

Chugwater they probably do not persist to the Big Horn and Deadwood formations. Other, small folds, such as the Gooseberry dome 

and anticline (No. 36), may not persist below the Madison limestone. 

Some of the minor structures, such as the terrace in the southeastern 

part of T. 45 N., R. 98 W., clearly lie on the limbs of larger anticlines.

In parts of the basin, particularly on the southeast, the crest lines 

of adjacent anticlines are approximately parallel, but in much of the 

region the crest lines, even where well defined, curve in broad arcs 

whose alignment bears little resemblance to that of those near by. 

Locally, several anticlines, such as the Lucerne (No. 28), Sand Draw 

(No. 30), and Waugh (No. 31), have nearly parallel crest lines and 

are successively offset (arranged in echelon), an arrangement that is 

common over large areas adjacent to the east front of the Rocky 

Mountains. This arrangement is uncommon in the northwestern 

part of Big Horn Basin.

It is an interesting fact that the dips on the anticlines and domes 

of the region are usually much steeper on one limb than on the 

other that is, the folds are unsymmetrical. A line drawn N. 30°- 

40° W. through the middle of the basin will separate the anticlines 

and domes into two groups, one northeast of the line in which 

the limbs nearest the central part of the basin are much flatter and 

broader than the limbs toward the Big Horn Mountains, and the 

other group southwest of the middle axis, in which the limbs nearest 

the basin are much flatter and broader than the limbs nearest the 

Owl Creek and Shoshone mountains. There are a few exceptions to 

this general rule. (See fig. 2.)

On account of great difference between the dips of the opposite 

limbs of several of the anticlines of the Big Horn Basin it is desirable 

at this place to call attention to the effect of these relations on the 

location of drill holes. (See fig. 2.) Evidence has been collected in 

several parts of the basin which tends to show that the thickness of the 

Cody shale is not constant throughout the extent of an anticline, 

and that the beds are generally thicker on the steep than on the flat
t- Parallel fb/d. Probably on£roccura jn strony jviissii/c beds, auch - 

sandstone and- limes-tone. f,r/fS.<J.tf,crV3ts, and'3,9.0. ax 

of various -beds.

-Sirf.'iJ&r foRT. "Thin beds of nfealf rocks, scfcfr Sg'ishate. arid ' thin 

SondsHone, tfnd "to essurrig thi'9 form.

2. Parallel fold in m

cut the high

<ft Simflar- fold in'sH

" wi/l-fall to 

FIGURE 2. Cross sections of inclined folds of two types, showing the relations of wells 
36 ANTICLINES IN SOUTHEBN PART OF BIG HORN BASIN, WYO.

limb. Thus the thickness of the Cody shale on the west limb of the 

Sunshine anticline is 3,400 feet, whereas the average of two measurements on the east limb is 2,600 feet. It seems highly probable that 

there are similar variations in thickness of the Thermopolis and 

Mowry shales and the Frontier formation. These relations suggest 

that the parts of the anticlines that include these formations are 

"similar" rather than "parallel" folds. (See p. 35.) It is an 

important feature of similar folds that the highest parts or crest traces 

of their component beds lie not vertically one above the other but 

along a plane that dips in the same direction as the flat limb. One 

important consequence of these relations is shown in figure 2, 

diagram 4, where a well drilled at X, on the crest trace of the outcropping bed, falls to the left of the crest trace of a lower bed at Y. 

In order to strike the crest of the buried bed at Y the well must be 

located at Z.

A very interesting question that has some economic importance is 

whether the pronounced folds of the border belt persist toward the 

trough of the basin under the cover of the Wasatch and younger 

rocks. The evidence that bears upon this question will not be 

summarized here, but reference may be made to two significant 

factors. In most parts of the basin the folds of the border belt are 

successively shorter and narrower and the dips lower the closer they 

are to the trough of the basin; and there is reason for inferring that 

these lower and smaller folds do not persist so deeply in the rocks as 

the larger folds. It seems probable, therefore, that any folds that 

involve the oil-bearing formations under the cover of the Wasatch 

and younger rocks are much less pronounced than those of the border 

belt. Several folds, whose crest lines trend northwest and are therefore roughly parallel to the folds of the border belt, have been noted 

in the areas of the Wasatch and younger rocks, but are probably not 

so pronounced in rocks as deeply buried as the Frontier. It is well 

to bear in mind, however, that very low anticlines may aid the 

accumulation of oil and very-low synclines may affect the direction 

of its migration.

FAULTS.

Faults occur in many of the anticlines of the basin. Most of them 

appear to be closely related to the movements by which the anticlines of the border belt were produced, for they displace the beds 

along the limbs. Thus, an important fault in sec. 2, T. 50 N., R. 

100 W., trends toward the syncline that separates the Oregon Basin 

North and South domes. The maximum stratigraphic displacement along this fault is 1,500 feet and the horizontal offset of the 

lower Mesaverde sandstone is 3,000 feet. Most displacements along 

these faults, however, range from 150 to 200 feet. Several faults,
STRUCTURE. 37

such as two in the northeast part of T. 45 N., K-. 99 W., are much 

more recent than the faults along the folds, for they displace the beds 

of Tertiary volcanic tuffs that unconformably overlie the older folded 

rocks.

In some localities, such as the Greybull dome (No. 4, fig. 5, p. 57), 

groups of parallel faults trend nearly at right angles to the crest line 

of a fold, but in other parts of the basin the faults roughly diverge 

from the crest of the anticline. This is well shown near the crest of 

Cottonwood anticline (No. 32) and around Oregon Basin. Viewed 

broadly, more faults have been recognized that displace the sandstone 

beds of the Frontier than any other formation; relatively few faults 

have been found in the areas of Wasatch rocks. No definite relations 

in the distribution of the faults have been recognized. Thus, there 

appears to be no reason why faults should be lacking in the Buffalo 

and Spring Creek basins and numerous and extensive in the Oregon 

Basin on the north and the Grass Creek Basin on the south.

STRUCTURE CONTOURS AND THEIR USE.

In all matters that pertain to geologic structure it is necessary to 

bear in mind that although the vertical dimension is important, most 

observations are made on the surface of the earth and are fixed by 

horizontal measurements only. Thus, most geologic maps show the 

surface outcrops, which involve two horizontal dimensions, supplemented perhaps by vertical cross sections which show one horizontal 

and one vertical dimension. Models may be constructed that show 

both horizontal and vertical dimensions in their true relationships, 

but these involve much labor in their preparation and can not readily 

be duplicated or reproduced in print.

A method of presenting the data of three dimensions, namely, the 

two surface or horizontal dimensions and the vertical, that has been 

found to be very useful is that embodied in the structure-contour 

map. On such a map the structure of beds lying entirely below the 

surface may be accurately shown. A contour map of any surface, 

whether the surface of the earth or the surface of a folded bed of 

sedimentary rock, is one that shows the contours or lines which would 

be formed if the surface were cut by many equidistant horizontal 

planes. If the surface considered be a plane or flat inclined surface 

the contours will be straight, and if it be a folded or irregularly curved 

surface the contours will be curved or highly sinuous. Such lines 

have been aptly described as the paths that would be traversed if a 

person were to walk along the surface, all the while being careful to 

maintain the same height above sea level. A structure-contour map 

shows many such lines or paths on the surface of a bed of rock as they 

would appear if viewed vertically downward from an elevated position.
38 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO. -

In general, the accuracy of structure-contour maps depends on the 

amount and kind of data available. In some oil fields where many 

well records to a persistent bed are known, exceptionally accurate 

maps of the buried bed may be made. Fairly accurate interpretations of the structure of buried beds have also been made in fields 

where only surface outcrops of higher beds were available, but in such 

cases the distance between the buried and outcropping beds has been 

measured from near-by outcrops and has been found to be fairly constant over large areas. In fields where surface outcrops are poor 

structure-contour maps may represent only approximately the form 

of buried beds but may yet be very useful in locating wells.

Figure 3 illustrates the meaning of a structure-contour map, and 

shows how it represents the form of an anticline. Figure 3, a, is a 

perspective sketch of a region in which the surface bevels a part of an 

anticline. This should be compared with Plate X, A (p. 98), which 

is reproduced from a photograph of a similar fold. The aim has been 

to represent an anticline from which a part of the fold has been 

eroded, as is common in the Big Horn Basin. The soft rocks are 

worn down to rolling plains, whereas the thick beds of resistant rock 

form prominent ridges, which form roughly elliptical outcrops around 

the end of the anticline. Figure 3, a, also shows a vertical cross section through the anticline. This type of anticline, where one limb 

has a low dip and the other a relatively steep dip, is common in the 

Big Horn Basin. If the anticline were cut horizontally by a knife at 

intervals of 500 feet, beginning at sea level, the position of some of 

these cuts would be represented by the horizontal lines at 3,000,3,500, 

4,000, 4,500, and 5,000 feet elevation; for instance, the line along 

which the knife cuts the top of the sandstone XYZ would be represented by the curved lines shown in the sketch. These lines not only 

show how the bed of sandstone would be cut, but collectively they 

also represent the form of the bed that is cut that is, they are what 

are generally known as structure contours on the bed. Figure 3, 6, 

shows the structure contours on the upper surface of the bed of sandstone X YZ as they would appear if viewed from a point vertically 

above the area. The contours are represented as solid lines below 

the surface and as broken lines where they are drawn on that part of 

the bed which once existed above the present surface but which has 

been removed by erosion. It is apparent that the distance between 

the contours is a measure of dip of the beds at that point; that where 

the distance between the contours is great the dip of the beds is low; 

and that where the contours are close together the dip is steep.

In addition to showing the form of a bed a structure-contour map 

may be used to determine, at any point on the surface whose elevation is known, the depth to the bed on which the structure contours 

are drawn. The depth to a bed either higher or lower in the section
STEUCTXJRE. 39

than that on which contours are drawn may also be obtained from 

the map, provided its distance above or below the contoured bed is

FIGURE 3. a, Cross section and perspective sketch of an anticline, showing meaning of structurecontours; 

6, structure-contour map of the anticline shown in the sketch.

known. In the maps of most of the fields considered in this report 

the structure contours are drawn on the top of the Greybull sand, but
40 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

in others they are drawn on the top of the Madison limestone, the 

Embar formation, or the coal beds in the lower part of the Mesaverde 

formation. Figure 4 has been prepared to show how the elevation 

above sea level and hence the depth from the surface of beds higher 

or lower than that on which contours are drawn, may be determined. 

If (see fig. 4) the bed pqrs lies below the bed Imno, on which the 

structure contours are drawn, the vertical distance from a given 

point, &, on the surface of the ground, to the top of the lower bed at r 

will be found by adding to the depth to the contoured bed In an 

amount approximately equal to the stratigraphic distance nr 

between the surfaces of the two beds, provided the beds are practically horizontal. The depth to a bed above the contoured stratum 

may be obtained by subtracting the stratigraphic distance, provided 

the beds are practically horizontal. If, however, the beds at the

FIGURE 4. Diagram showing the relation of a bed that is contoured to other beds either above or below.

given point dip more than'5°, the distance nr will appreciably exceed 

the stratigraphic distance between the beds. It will be equal to the 

stratigraphic distance divided by the cosine of the angle of dip.

In many of the fields described in this report a part of the bed on 

which contours are drawn and of the overlying beds has been removed 

by erosion and the contours represent the inferred position of the 

surface of the bed (above the existing surface of the ground) before 

it was eroded. Thus, the structure of large parts of several fields is 

shown by contours on a coal bed of the Mesaverde formation, which 

has been restored in those areas from which the bed has been eroded. 

In these fields the sands in which there is some prospect of finding 

oil and gas occur in the Frontier or lower formations. The calculation of the depth to these lower sands is not so simple as it is where 

the contoured bed is uneroded. If in figure 4 there are known the 

elevations of a point &, on the surface of the ground, and that of the
MODE OP OCCUBBENCE OF OIL AND GAS. 41

point e, vertically over it on the restored surface of a contoured 

bed, the depth bi to the point i on a lower bed is the distance ei 

(the stratigraphic distance fh between the two beds divided by the 

cosine of the angle of dip) minus the distance be (the difference in the 

elevation of the surface of the ground and that of the restored bed). 

The foregoing discussion is based on the assumption that the beds 

are parallel, which is equivalent to saying that the shortest distance 

between the two beds is equal throughout the fold. There may be 

areas in which the beds are not parallel, and for these the calculations 

are only approximately correct.

OIL AND GAS.

MODE OF OCCUBBENCE.

DATA CONSIDERED.

In order to determine whether or not any particular anticline or 

dome in the Big Horn Basin is probably a reservoir for large quantities of oil or gas the authors have considered three classes of data 

(1) specific information that has been obtained by drilling on each 

anticline, in so far as it relates to the character of the rocks that 

remain buried beneath the surface on the crests of anticlines, and 

the areal relations of the anticlines; (2) general knowledge of the 

occurrence of oil and gas in districts in Wyoming where stratigraphic 

and structural conditions are similar to those existing at the particular 

anticline; and (3) hypotheses relating to the accumulation of oil and 

gas in anticlinal folds.

SPECIFIC INFORMATION OBTAINED BY DRILLING.

The beds that have yielded most of the oil and gas in Big Horn 

Basin are Cretaceous in age and are parts of the Cloverly formation, 

Thermopolis shale, Mowry shale, and Frontier formation. Gas is 

reported also from a sand in the Morrison formation in well No. 4 

on the Shoshone anticline. An oil seep is known near the base of 

the Chugwater formation on the Red Spring anticline and another is 

reported by Washburne x in T. 52 N., R. 90 W., in beds that may be 

part of the Amsden, Tensleep, or Embar formations. It is extremely 

uncertain at present, however, whether any of the beds lower than 

the Cloverly formation will prove to be important sources of oil or 

gas. Only one well (on the Nieber anticline) has tested, under 

favorable structural conditions, beds higher than the Cody shale, 

which overlies the Frontier formation, but on account of the origin 

and lithologic character of the higher beds the prospect that any of 

them will yield important quantities of either oil or gas is not good.

1 Washburne, C. W., Gas fields of the Bighorn Basin, Wyo.: U. S. Geol. Survey Bull. 340, p. 361,1908.
42 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

The results of drilling to date in the, Big Horn Basin show that the 

sands of the Frontier formation yield the greatest part of the oil 

and that the sands of the Mowry shale and the Greybull sand yield 

oil as well as most of the gas now produced in the basin. These 

facts are cited to indicate not that other formations offer no prospect 

for successful drilling, but that preliminary exploration should be 

confined to these formations. Areas that are structurally favorable 

should not be considered to be proved valueless until all of the sands 

of these formations, which include from 1,600 to 1,800 feet of beds, 

have been tested.

Some of the anticlines and domes in the Big Horn Basin are not 

regarded as good reservoirs for oil and gas because the beds that are 

most likely to serve as reservoirs have been eroded from the crests, 

thereby permitting the escape of the oil and gas, if those substances 

were ever present.

Some anticlines in this region are considered by the writers to be 

unpromising as oil and gas reservoirs for the additional reason that 

they pitch in such a way that any oil or gas in them would escape 

to the surface at the outcrops of the oil and gas sands. A good 

example is the southeast end of the Lucerne anticline (No. 28, 

PI. I), which is developed on the north side of the large Thermopolis 

anticline (No. 27, PL I) and which pitches northwest as far as the 

cross syncline separating it from the part designated the Gebo dome. 

Any oil or gas that originally may have been in the strata in this 

anticline could have migrated up the beds and escaped at the outcrop 

on the north side of the Thermopolis anticline.

The wells that have' struck large quantities of oil and gas in the 

Big Horn Basin are near the crests of anticlines and domes. Of those 

wells drilled near synclines or where the beds are nearly flat over 

large areas a few have struck small quantities of oil and gas and a 

few have failed to yield oil, gas, or water, but most have yielded 

water. In several of the productive fields that are on anticlines 

water is found in sands both above and below the oil and gas sands.

In general, the relations of gas, oil, and water in the anticlines are 

those demanded by the simplest interpretation of the "anticlinal" 

theory, as set forth by Orton l in 1886:

If one of these sandstone strata filled with salt water, oil, and gas and freely permeable laterally and horizontally for miles at a time were thrown into a system of low 

folds, what effect would this movement have upon the contents of the stratum? 

Would not a separation of gas, oil, and water be sure to follow, the gas finding its way 

to the summits of the arches and the salt water sinking to the bottoms of the troughs? 

Such a result would be inevitable under the conditions assumed.

According to the theory, if gas, oil, and water are present in large 

quantities and if the adjustment in the pervious bed according to the

1 Orton, Edward, Preliminary report upon petroleum and inflammable gas, p. 13, Ohio Geol. Survey, 

1886.
MODE OF OCCURRENCE OP OIL AND GAS. 43

specific gravities of the substances were complete the gas would 

occupy a zone at the highest part of the folded beds and be limited 

below by the roughly horizontal upper surface of a zone of oil. The 

zone of oil, in turn, would be limited below by the roughly horizontal 

upper surface of a zone of water. If the proportion of gas were relatively low it is conceivable that all of it could be dissolved in oil 

under the existing pressures, and the oil rise to the highest part of the 

fold. The available information from the productive fields of Big 

Horn Basin shows that in this region much less gas is present than is 

commonly associated with productive oil pools.

The limits of the oil-producing areas of several of the important 

fields of the basin have been approximately determined and in comparison with most oil pools are rather sharply defined. Thus, after 

two years' operations, the limits of the productive areas of the Grass 

Creek field are rather closely determined, and it appears that a broadly 

sinuous line may now be drawn which will separate the inner area, 

within which all wells that penetrate the productive part of the 

Frontier formation will yield oil with little if any water, from the 

outer area, within which all wells will yield water from the same zone 

of sands. The limits of the other fields of the basin are not yet so 

closely known. Each prominent anticline that contains oil appears 

to hold but a single pool.

In the three most productive fields in the area covered by this 

report, the Greybull, Torchlight, and Grass Creek, the zone in the 

prolific sands that yields the oil extends much lower along a part of 

the flat basinward limb of the fold than on the steep mountainward 

limb. Thus at Grass Creek the sands are prolific at a lower altitude 

in the southeastern part of the field than in the southwestern or 

western part. This relation must be considered in formulating any 

hypothesis to explain accumulation of valuable pools of oil.

In one well (No. 31, fig. 5, p. 57) in the Greybull field the .oil which 

was first produced by pumping has given way to water, and in another well (No. 32, fig. 5) the gas has gradually given way to oil. The 

latest well is near the line separating oil and gas.

A summary of the results of drilling throws light on the possible 

relation of productiveness of anticlines and domes to their position 

with respect to near-by larger basins and upfolds. Fifty fairly distinct upfolds have been described, but it should be recognized that 

it is not possible to "distinguish sharply between simple isolated upfolds and outlying parts of complex upfolds. Thus, the Lucerne 

anticline is regarded as a single distinct upfold, although it includes 

the Gebo dome, which lies along the extension of its crest line. Wells 

have been drilled sufficiently near the crest .lines of 24 of the 50 upfolds to indicate the prospect for production from the structures. In 

the following summary, compiled from the descriptions hi this report,
44 ANTICLINES IN SOUTHERN PART OF BIG HORN BASlN, WYO.

upfolds are considered to dip basinward if their beds descend without 

reversed dips to the middle trough of the Big Horn Basin. In several upfolds as in Little Grass Creek dome, for instance- the area 

within which the beds dip continuously toward the middle of the 

basin is only a small part of the total area of the basinward-dipping 

limb of the fold, but such upfolds are nevertheless included among 

the basinward group.

Upfolds in Big Horn Basin.

East side of middle trough.

BASINWARD UPFOLDS.

Tested by drill:

Greybull dome.................. OG

Lamb anticline................. OG

Torchlight anticline............ OG

Manderson anticline............ ?

Bonanza anticline.............. o

Sherard dome.................. o

No Wood anticline.............. w

Not tested:

Tensleep anticline. 

Bud Kimball anticline. 

Well area. 

Sheep Mountain anticline.

MOUNTAINWAKD UPFOLDS.

Tested by drill:

Shell Creek dome.........

Cherry anticline............

Dry dome.................

Mercer anticline............

Paintrock anticline.........

Not tested:

Zeisman dome.

Brokenback anticline.

d 

d

W 

w

W

West side of middle trough.

BASTNTVABD UPFOLDS.

Tested by drill:

Nieber anticline................. ?

Grass Creek anticline............ OG

Little Grass Creek dome......... W

East Buffalo anticline.......... g

West Buffalo anticline.......... g

North Oregon Basin dome...... g

South Oregon Basin dome...... g

Shoshone anticline.............. og

Not tested:

Mahogany Butte anticline. 

Lysite'Mountain anticline. 

Black Mountain anticline. 

Lake Creek anticline. 

Sand Draw anticline.

MOUNTAINVTABD UPFOLDS.

Tested by drill:

Lucerne anticline...........

Waugh anticline............

Cotton wood anticline........

Wagonhound anticline.......

Enos Creek anticline.......

Spring Creek anticline.......

Gooseberry anticline.......

Not tested:

Zimmerman Butte anticline.

Blue Spring anticline.

Red Spring anticline.

Wild Horse anticline.

Thermopolis anticline.

Gooseberry dome.

Sunshine anticline.

South Sunshine anticline.

Fourbear anticline.

Pitchfork anticline.

Half Moon anticline.

Frost Ridge anticline.

w 

W

d 

W 

W 

W 

W

OG Important oil and gas field.

og Unimportant oil and gas field.

o Unimportant oil field.

g Wells near crest line yield gas only.

W Wells near crest line yield water.

d Wells "dry"; yield no oil, gas, or water.

w Well some distance from highest part of crest yields water.

? Well near crest line not deep enough to test important sand.
MODE OF OCCURRENCE OF OIL AND GAS. 45

The data given above may be summarized as follows:

Basinward upfolds tested by wells:

Important oil and gas fields............................... 4

Unimportant oil and gas fields.............................. 1

Unimportant oil fields...............................'..... 2

Fields that yield-gas only................................. 4

Fields with shallow wells that do not reach productive sands. 2 

Fields that yield water only.............................. 2

 15 

Basinward upfolds untested................................... 9

Mountain ward upfolds tested by wells:

Fields that yield water near crest.......................... 7

Fields that have dry wells................................. 3

Fields that yield water remote from crest................... 2

 12 

Mou'ntainward upfolds untested.........'....................... 14

50

The preceding summary is statistical and does not contain many 

details that should be included in a complete review of the results of 

the drilling, but its significance should not be overlooked in considering the chance for success in drilling in this region. It can hardly 

be merely a coincidence that every tested field in the Big Horn 

Basin which has yielded appreciable quantities of oil and gas lies 

near the principal trough of the Big Horn Basin, and that every 

tested upfold which ip separated from this trough by other folds 

has either yielded water and the merest traces of oil and gas or is 

barren of either oil, gas, or water. These relations of course do not 

necessarily indicate that every basinward anticline should yield 

either oil or gas and that no mountainward anticline will yield oil 

or gas in commercial quantities. They do suggest, however, that 

basinward upfolds offer more favorable prospects for exploitation 

and should be tested in advance of the others.

OCCURRENCE IN OTHER FIELDS IN WYOMING.

There are many anticlines and domes in Wyoming that are of 

nearly the same size as those described in this report and that, 

like them, lie in belts between much larger anticlines or between 

regions of uplift and regions of depression. As the structure of the 

Cretaceous beds in large areas near these depressions or basins is 

obscured by unconformable younger beds it is not possible to be 

sure in each locality whether the upfolds adjacent to the limits of the 

later beds are basinward, as the word is used in this report, or not. 

It may be noted, however, that the most productive oil field in the 

State, Salt Creek,1 is basinward with respect to the Powder River

i Wegemann, C. H., The Salt Creek oil field, Natrona County, Wyo.: U. S. Geol. Survey Bull. 452, p. 37, 

1911.
46 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

basin, and that several minor oil fields, such as Moorcroft, 1 in Crook 

County; Big Muddy,2 in Natrona County; Byron,3 in Big Horn 

County; and Elk Basin,4 in Park County, are among folds that are 

nearest to the larger structural depressions.

Wegemann 5 has called attention to the relation of the Salt Creek 

dome to the structural basin which lies on the east between the Big 

Horn Mountains and the Black Hills. He has noted that this dome 

is an important factor in the accumulation of the oil because it has 

a large area from which oil might be collected through the selective 

action of the differences in specific gravity of oil and water or through 

other agencies. Though the sandstones that contain the important 

pools of oil hi the Salt Creek anticline rise to the surface in the Powder 

River anticline, 15 miles to the northwest, it appears that the larger 

accumulations in the Salt Creek field, as shown by the success attending drilling to date, may be attributed in part to the more favorable 

position of the Salt Creek dome with reference to the structural basin 

on the east.

HYPOTHESES AS TO ACCUMULATION.

No hypothetical considerations as to which anticlines are apt to 

yield oil and gas are to.be compared with those which may be drawn 

from the foregoing statistical inquiry as to which fields are likely to 

be productive. If with further exploration it should prove true that 

basinward folds are much more productive than mountainward folds 

it would suggest, as Wegemann has pointed out, that large accumulations of oil and gas in the Cretaceous beds of Wyoming are possible 

only where upfolds are adjacent to large areas of gently rising beds. 

In other words, the quantity of oil and gas in the upfolds bears a 

close relation to the area of beds from which it is possible for oil and 

gas to rise.

If much were known concerning the chemical character of the 

water in the Big Horn Basin oil fields, and concerning the pressure of 

the water in many wells that tap- persistent sandstones, it might be 

possible to draw inferences concerning the movement of water in the 

beds. Although the beds in which most if not all of the oil and gas 

are found were laid down in the sea, the waters which some of the 

beds in the oil fields now contain are not strongly salty and are apparently feebly alkaline. This suggests that there have been accessions 

of surface waters to the beds, probably from the outcrops; and if 

such movement has taken place on a large scale it would be reasonable 

to conclude that it might produce accumulations of oil and gas in

1 Barnett, V. H., The Moorcroft oil field, Crook County, Wyo.: U. S. Geol. Survey Bull. 581, p. 94,1913.

2 Barnett, V. H., Possibilities for oil in the Big Muddy dome, Natrona County, Wyo.: Idem, p. 105. 

a Washburne, C. W., Gas in Bighorn Basin, Wyo.: U, S. Geol. Survey Bull. 340,'p. 357,1908. 

« Personal communication from C. J. Hares. 

GWegemann, C. H., op. cit., p. 76,
MODE OF OCCURRENCE OF OIL AND GAS, 47

upfolds accessible to the paths of movement. If this had taken 

place to any great extent some of the mountainward folds should 

yield important quantities of oil and gas; but not one of the 12 (out 

of a total of 26) mountainward folds that have been tested has 

yielded more than a trace of oil and gas.

From all the information now available, therefore, it appears that 

the large accumulations of oil and gas in this region have been formed 

by slow adjustment of the oil, gas, and water once disseminated in 

the beds. As the productive areas of the most important anticlines 

of the basin extend lowest in the sands of the limb nearest the middle 

trough of the basin, it seems that the adjustment of the mobile substances is not yet complete.

If the foregoing hypothesis is correct it may be noted, in conclusion, 

that a possible explanation of the extraordinary natural flow and consequent large yield of the wells in the Salt Creek field, in contrast 

with the practical absence of flowing wells in the Big Horn Basin 

fields, may be due to the fact that although the structural depressions 

of the Powder River and Big Horn basins are almost equal in size, 

there are many more, possibly six times as many, upfolds adjacent 

to the Big Horn Basin than there are adjacent to the Powder River 

basin.

The following table summarizes the principal facts known about 

the domes and anticlines:
Anticlines and domes in the south half of the Big Horn 

No. 

on map 

(PI. if.

1 

4 

2 

3 

5 

6 

8 

7 

10

9 

11 

14 

12 

13 

16 

15

17 

18 

19

20 

21 

22 

25

24 

26 

23 

28

29 

30

31 

27 

32 

33

Name.

Dry......................................

No Wood. ................................

Waeonbound. ............................

Wells.

Date 

of first 

well.

1907 

1915 

1915 

1907 

1904 

1914 

1910? 

1900

1888 

1898?"

1914

1915 

1915

1914 

1910? 

1912 

1915

Number.

. 53+ 

1 

1 

11 

53+ 

1 

1 

3

3 

6

7

1

1

4 

1 

2 

3

Product of wells.

Oil and gas........

Nonproductive. . . . 

.....do....... . .... 

Oil and gas.. ......

.....do............

.....do............

.....do............

.....do............

.....do.......;....

.....do. ...........

.....do............

.....do............

Formation exposed 

at top of dome 

or anticline.

Sundance ......... 

Cody... ...........

Cody..............

Thermopolis......

.....do. ..........

....do. ...........

Cody..............

Thermopolis......

Fort Union......'.

.....do............

Thermopolis ......

Cody..............

O

Fron
8Wf t-l i

34

QE

36

37

OQ

on

4A

41

42

43

11

46

AK

47

AQ

Grass Creek

Goose l)eiTv

1913?

1916

1913?

1Q1 C

1912

1Q1 9

1QOO

R1 I

i4133

.....do............

.....do............

.....do............

.....do............

.....do............

.....do............

.....do............

.....do............

.....do............

oi

o Oil was discovered in a seep here about 1884.

6 "Oil" in the remainder of the table is intended to include both 
50 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO. 

PHYSICAL AND CHEMICAL CHARACTERISTICS.

Most of the oil of the Big Horn Basin is of high grade, averaging 

about 45° Baume1 . It ranges in specific gravity from 0.8982 to 

0.7856 (25.9° to 48.2° Baume"), and yields from 3.5 to 35 per cent of 

gasoline by the usual fractionation method. The kerosene content 

of the oil as it comes from the wells ranges from 22.5 to 55.7 per cent. 

The lightest ,oil is transparent and has a deep wine color in transmitted light and a dark-green color by reflected light. The heavier 

oil is opaque and varies from green to dark green by reflected light. 

Oil from the Lamb anticline near Basin, Wyo., according to one 

analysis, is heavier than that known from any other part of the Big 

Horn Basin. It contains no gasoline and much less kerosene than 

the oil of Torchlight dome a few miles to the south. The small 

quantity of oil that has been obtained from the Embar and Madison 

formations is also, very heavy. Near Lander, Wyo.,1 the Embar 

yields commercial quantities of oil that ranges in specific gravity 

from 0.9198 to 0.0091 (22.2° to 24° Baum6) and that contains less 

than 3 per cent of gasoline and at no place more than 25 per cent of 

kerosene.

The gas of the Big Horn Basin is much less valuable at present 

than the oil, because it occurs in small quantities and can not be 

utilized to a large extent. Large quantities of gas have been tapped 

in drilling on the Lamb anticline, Greybull dome, East and West 

Buffalo anticlines, North and South domes of Oregon Basin, and Byron 

anticline. A well recently drilled by the Ohio Oil Co. near Byron 

in the northern part of the basin but not described in this report is 

said to have yielded 40,000,000 cubic feet of gas during the first 24 

hours. Plans are already being made to pipe gas from some of these 

fields to the nearest large cities, such as Billings and Butte, Mont., 

and Salt Lake City, Utah.

Analyses of gas from the Greybull and Byron fields show that it 

is partly "wet" that is, that it contains in addition to methane 

considerable quantities of gases from which gasoline can be derived by 

compression, as stated by Burrell.2 Calvert 3 believes that the gas 

of the Big Horn Basin is not promising as a source of gasoline because 

the greater part of it is under high pressure, and '' the gas from the 

high-pressure well is adapted only for use as fuel and illuminant." 

However, gas may yet be discovered in the Big Horn Basin that 

may have especial value as a source of gasoline.

All known analyses of oil and gas in the Big Horn Basin are given 

in the following tables. All samples, unless otherwise stated, were 

collected by members of the United States Geological Survey.

i Woodruff, E. G., The Lander oil field, Wyo.: U. S. Geol. Surrey Bull. 452, pp. 7-36.1911.

a Burrell, G. A., The suitability of natural gas for making gasoline: Bur. Mmes Teen. Paper 57, p. 20, 

1913.

8 Calvert, W. R., A preliminary report on the utilization of petroleum and natural gas in Wyoming: 

Bur. Mines Tech. Paper 57, pp. 12,14,1913. t
Analyses of oils from the Big Horn Basin, Wy

[Made in chemical laboratory of the Bureau of Mines

Anticline or dome.

Name.

1. Greybull....

2. Lamb a ..... 

3. Torchlight o.

4. Torchlight o.

5. Sherard ..... 

6. Grass Creek . 

7. Grass Creek. 

8. Shoshone & . . 

9. Shoshone &.. 

10. Byron c .....

No. on 

map 

(PI- 1).

2

5 

6

6

15 

33 

33 

45 

45 

W 

<«)

No. 

of 

well.

29

20 

27

9

6 

35 

28 

2 

2 

(1) 

(2)

Depth 

of 

well.

975

1.088 

1,350

1,264

102 

1,053 

987 

585 

1,028

(?) 

400±

Physical properties.

Gravity of crude 

oil at 60° F.

Specific.

0. 7856

.8889 

.8260

.7955

.8982 

.8187 

.7984 

.8454 

.8335

(Atl5°C.)

.8174 

.8187

Baume' 

(°).

48.2

27.5 

39.5

45.98

25.9 

41 

45.3 

35.6 

37.98 

42 

41

Color in 

reflected light.

Dark green. . . .

Brownish green 

Dark green....

.....do.........

Brownish green

Very dark 

green. 

Olive green....

Dark green. ...

Olive green.... 

Dark green....

Distillation by Engl

Begins 

to boil 

(°C.).

3

180 

75

34

68 

80 

28 

190 

160

(0

44

By vo

To 150° C. 

(gasoline).

Cubic 

centimeters.

31

26 

30.5

3.5 

22 

35

4.7 

29

Specific 

gravity.

0.7120

.7444 

.7216

.7948 

.7530 

.7290

(')

.7444

150°-30

(kerose

Cubic 

centimeters.

32.5

22.5 

34.5

38

27 

42 

32 

37 

48 

55.7 

42.5

S

g

:, 

a Published in U. £ Geol. Survey Bull. 621, pp. 182,183,1916. 

6 Published in U. S. Geol. Survey Bull. 541, p. 113,1914. 

c Published in Bur. Mines Tech. Paper 57, p. 10,1913.

d Byron antic

e These data 
52 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

1. Greybull dome, well 29. Sample collected on June 12,1915, from the George 

Alford No. 2 well of the Bighorn Oil & Gas Co., NW. \ SE. J see. 17, T. 52 N., E. 

93 W.

2. Lamb anticline, well 20. Oil collected from the Wilson No. 1 well of the Greybull Oil Co., NW. i NW. isec. 1, T. 51 N., B. 93 W., in June, 1914, and stored in an 

air-tight barrel until October 15 of the same year, when a sample was sent to the 

laboratory for analysis.

3. Torchlight dome, well 27. Sample collected on October 15,1914, from the Jackson No. 3 well of the Greybull Oil Co., NE. \ SW. \sec. 24, T. 51 N., R. 93 W. This 

sample reached the laboratory unsealed and probably some of the gasoline had 

evaporated.

4. Torchlight dome, well 9. Sample collected on October 15,1914, from the Kimball No..3 well of the Greybull Oil Co., lot 13, sec. 19, T. 51 N., R. 92 W.

5. Sherard dome, well 6. Sample collected on August 30, 1915, from well No. 6, 

drilled by H. M. Sherard for an association of persons in Greybull and Basin, in the 

NE. i NE..i sec. 19, T. 47 N., R. 89 W. The sample was dipped from the top of the 

casing and undoubtedly some of the volatile constituents had escaped.

6. Grass Creek anticline, well 35. Sample c.ollected from well of the Valentine 

interests in the N. \ N. \ sec. 20, T. 46 N., R. 98 W., on September 11, 1914, before 

the well was completed.

7. Grass Creek anticline, well 28. Sample collected on July 26, 1915, from the 

Phelps well of the Ohio Oil Co., SW. \ NW. \ sec. 19, T. 46 N., R. 98 W.

8. Shoshone anticline, well 2. Sample collected in October, 1911, from well No. 2 

of the Shoshone Oil Co., SE. \ SW. \ sec. 21, T. 53 N., R. 10 W.

9.. Shoshone anticline, well 2. Sample collected in October, 1911, from well No. 2 

of the Shoshone Oil Co., SE. \ SW. J sec. 21, T. 53 N., R. 10 W.

10. Byron anticline, well 1. Sample collected by W. R. Calvert in the winter of 

1912-13 from well No. 5 of the Montana-Wyoming Oil Co., on the E. E. Jones lease in 

sec. 34, T. 56 N., R. 97 W.

11. Byron anticline, well 2. Sample collected on October 22,1914, from well No. 12 

of the Montana-Wyoming Oil Co., on the E. E. Jones lease in sec. 34, T. 56 N., R. 97 W.

Oil from the Bonanza seep in the NW. \ SW. \ sec. 23, T. 49 N., 

R. 91 W., has been studied by E. E. Slosson, of the University of 

Wyoming, who gives the following results of his investigation:

Distillation of Bonanza petroleum.® 

[Specific gravity of crude petroleum, 0.860, or 34.6° Baume".)

Boiling

point (° C.)

60-157

157-200

200-237

237-273

273-297

297-329

329-371

371-391

Gravity of distillate.

Specific.

0.762

.792

.822

.843

.853

.867

.876

.861

Baume* (°).

53.5

46.5

40.3

36.1

34.1

31.4

29.8

36.6

a Fisher, C. A., Geology and water resources of the Bighorn Basin, Wyo.: U. S. Geol. Survey Prof. Paper
GENERAL DEVELOPMENT. 53

Five samples of natural gas collected by displacement of air from 

wells in the Big Horn Basin have been analyzed in the laboratory of 

the Bureau of Mines, as follows:

Analyses of natural gas from the Big Horn Basin, Wyo. 

[G. A. Burrell, analyst.]

Labor&- 

tory 

No.

3224

3222

6851

5722

3220

Anticline.

Name.

Greybull..

.....do....

.....do....

Lamb....

Byron. . . .

No. 

on 

map.

(P1.I)

2

2

2

5

No.

of 

well.

9

2

24

23

Specific

gravity (airfree).

0.64

.77

.85

.59

.68

Carbon dioxide 

(COO0.20

.00

.10

.04

.47

Oxvgen 

(00.

0.00

.00

3.20

.00

.00

Methane 

(CHO.

81.70

51.55

38.70

93.5

64.05

Ethane 

(C.H).

17.3

47.20

42.50

3.5

32.28

Nitrogen 

(NO.

0.75

1.25

15.50

2.6

3.20

Heating

value

at 0° C. and

under 760 

mm. pressure (calculated).

1,192 B.t.u..

1,427 B.t.u..

1,203 B.tu..

1,061 B.t. u..

1,282 B.tu..

Remarks.

*

Claroline absorption 26.

Claroline absorption 22.6.

Amount of Oa

and Nj present

suggest that

bottle contained some

air.

Claroline absorption 18.2.

3224. From Island No. 1 well (No. 9 on fig. 5, p. 57) in the NW. i SW. i sec. 16, T. 

52 N., K. 93 W. Collected by W. R. Calvert, winter of 1912-13.

3222. From an unknown oil well in the same field from which some gas escapes. 

Collected by W. R. Calvert, winter of 1912-13.

6851. From Thomas Alford No. 1 (No. 24 on fig. 5), in the SE. J SW? i sec. 17, T: 

52 N., R. 93 W., in the Greybull field. Collected, June, 1915.

5722. From Lamb No. 1 well (No. 23 on PI. IX, p. 78) in the SE. J SE. J sec. 12, 

T. 51 N., R. 93 W., on the Lamb anticline.

3220. From an unknown well in the Byron field. 'Collected by W. R. Calvert, 

winter 1912-13.

GENERAL DEVELOPMENT.

Details of development are described later in connection with 

the individual anticlines and only a chronologic record of the 

development of the fields is here presented. Exceptions are made, 

however, in certain fields (Byron, Elk Basin, and others) that lie 

outside of the area covered in detail in this report.

TESTED DISTRICTS. 

BONANZA REGION.

The first discovery of oil in the Big Horn Basin is believed to have 

been made at the Bonanza oil seep in the NW. \ SW. \ sec. 23, T. 

49 N., R. 91 W., in 1884 by Edward Lloyd. No drilling was done 

in this locality until 1888, when a well (No. 12, PI. XI, p. 98) sunk 

to about 1,200 feet encountered a little artesian water but no oil 

or gas. Since 1888 a number of wells have been drilled in this
54 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

general locality, but none has found oil and gas in commercial 

quantities. The total production of this field is estimated to be not 

more than 50 barrels.

TORCHLIGHT DOME.

The Torchlight dome was the second field in the Big Horn Basin 

to be tested. In 1905 two shallow wells (Nos. 1 and 2, PI. IX, p. 78) 

drilled on the top of this dome encountered gas and a showing of 

oil. Since 1905 the field has been tested sufficiently to outline the 

pool, the development being due largely to the efforts of the Greybull 

Oil Co. The daily production of the field on the basis of 50 producing 

wells was estimated early in 1915 to be not less than 1,500 barrels.

BYRON ANTICLINE.

Gas was discovered in the Byron field, in the northern part of the 

Big Horn Basin, but outside the area covered by this report, in the 

winter of 1903 and 1904, but no drilling was done until 1906, when 

a well sunk by the Montana-Wyoming Oil Co. found oil. Since 1906 

the development of the field has been continuous, and some highgrade oil and a large amount of gas have been produced. The largest 

gas well in the State, said to yield 40,000,000 cubic feet of gas daily, 

was brought in by the Ohio Oil Co. in 1915. The daily production 

of oil was estimated in 1915 to be 300 to 400 barrels.

LAMB ANTICLINE.

The Lamb anticline was first tested in 1907, but only a showing of 

oil and gas was obtained, and it was not until 1913 that a large flow 

of gas was discovered, and not until 1914 that a heavy oil was struck. 

No oil is being produced at the present time.

GREYBTJLL DOME.

The Greybull field was first drilled in 1907, gas being discovered 

first and oil the following year. After 1908 many gas wells were 

brought in and the field was considered preeminently a gas field; 

later, however, wells farther from the top of the dome produced 

large quantities of oil, so that now the field is best known for its 

oil production. The daily production of oil in the Greybull field on 

April 1, 1916, was estimated to be 3,000 to 4,000 barrels.

SHOSHONE ANTICLINE.

The Shoshone anticline near Cody was first tested in the winter 

of 1909 and 1910. Oil and gas in commercial quantities have not 

been discovered in any of the wells and probably not more than 

200 barrels of oil has been produced during a period of two or three 

years.
GENERAL DEVELOPMENT. 55

OREGON BASIN DOMES.

The" Oregon Basin field was tested first in 1912. Considerable gas 

was encountered in two wells which have, however, yielded only traces 

of oil.

GRASS CREEK ANTICLINE.

The first drilling in the Grass Creek anticline is reported to have 

been done in 1913, but the first well to find oil in commercial quantities was not brought in until 1914. In October, 1916, about 193 wells 

had been drilled, 129 of which were pumping. It is estimated that 

if all the oil wells in this field were pumped the production would be 

between 6,000 and 7,000 barrels daily.

BUFFALO BASIN ANTICLINE.

The Little Buffalo Basin field, like the Grass Creek field, is reported 

to have been tested first in 1913; but the first well to produce gas 

in commercial quantity was not drilled until 1914. The gas wells 

have been capped and several new wells were being drilled in October, 

1916.

ELK BASIN ANTICLINE.

Oil in the Elk Basin anticline, situated on the State line between 

Wyoming and Montana, was discovered in October, 1915. A number 

of wells are producing oil and more are being drilled at the present 

time. A pipe line has been constructed from this field to Frannie, 

a station on the Chicago, Burlington & Quincy Kailroad, where there 

is a tank farm and loading racks. On July 1, 19.16, it was reported 

that 21 wells were producing and that the pipe line was transporting 1,000 barrels of crude oil daily.

OTHER DISTRICTS.

Drilling has been done on a number of other anticlines. The 

greatest development is being prosecuted on the Sherard dome on 

the east side of the basin, where in 1914 and 1915 seven wells were 

drilled, six of which found oil in small quantity. Probably not more 

than 25 barrels have been obtained in this locality.

Four wells have been drilled on the Waugh anticline, but none are 

productive.

The Cherry anticline, Shell Creek dome, Neiber anticline, Gebo 

dome on the Lucerne anticline, and Spring Creek anticline were 

tested in 1915 and the Wagonhound, Enos Creek, and Gooseberry 

anticlines and Little Grass Creek dome in 1916, but all have thus far 

failed to yield oil or gas in commercial quantities.
56 ANTICLINES IN BOUOTHERN PART OP BIG HORN BASIN, WYO.

REFINERIES.

The oldest refinery in the Big Horn Basin is at Cowley, on the Chicago, Burlington & Quincy Railroad, in the northern part of Wyoming, outside of the area described in this report. This plant has 

been hi operation for six years or more and is said to have a capacity 

of 160 barrels of crude oil a day.. It is connected with the Byron oil 

field by means of a pipe line about 7 miles in length. Up to 1915 

this plant was able to refine practically all the crude oil from the 

Byron field.

The largest refinery in the basin is at Greybull. It was begun in 

the spring of 1915 and was ready for operation by the end of that 

year. On July 1, 1916, it was reported to be refining 2,800 barrels 

of crude oil daily. It is now being enlarged and will soon have a 

capacity of 7,500 barrels of crude oil daily. This refinery is now 

under the control of the Midwest Refining Co. Before it was hi operation the crude oil was shipped principally to the refineries at Casper.

It is reported that a refinery is contemplated at Chatham, on the 

Chicago, Burlington & Quincy Railroad, the eastern terminus of 

the pipe line from the Grass Creek oil field.

PIPE LINES.

Four pipe lines (from the Byron field to the Cowley refinery, from 

the Torchlight dome to the Greybull refinery, from the Grass Creek 

field to Chatham, and from the Elk Basin field to Frannie) have been 

constructed in the Big Horn Basin.

THE ANTICLINES AND DOMES.

SHEEP MOUNTAIN ANTICLINE. 

By CHARLES T. LTJFTON.

The Sheep Mountain anticline (No. 1, PI. I), the southeast end of 

which is shown on the general map, is in the northeastern part of the 

Big Horn Basin. It was not examined in detail, and only a few 

general statements regarding it can be given.

The anticline is represented on the surface by a prominent ridge 

known as Sheep Mountain, the top of which corresponds approximately to the crest of the anticline. It is about 15 miles long and is 

cut by Big Horn River. The canyon thus formed is known as Sheep 

Mountain (Black) Canyon and has a maximum depth of about 1,000 

feet. The Chicago, Burlington & Quincy Railroad follows the west 

side of the river through this canyon.

The lowest rocks outcropping in the anticline belong to tihe lower 

part of the Madison limestone. They dip more steeply on the east
SHEEP MOUNTAIN" ANTICLINE. 57

or mountain side than on the west or basin side, as is shown by 

Plate I.

A well drilled for oil and gas to a depth of 1,000 feet near Spence, 

on Big Horn River a short distance northeast of the anticline, 

penetrated the Madison limestone and is reported to have found a 

trace of oil in the Embar and Amsden formations. The mouth of

&

Structure contours (lines of equal altitude) on'top of

Greybull sand. Numbers show distance .above ,#Gas well

sea level. Contour interval, 200 feet ^Dry hole

FIGURE 5. Structure-contour map of south end of Sheep Mountain anticline (No. 1, PI. I) and Greybull 

dome (No. 4, PL I) and structure section. The outcrops of sands are mapped as sandstone.

the well is said to be 200 feet below the top of the Chugwater formation ("Red Beds").

This anticline is of doubtful importance as a reservoir for oil and 

gas, as all the formations known to contain these substances in 

Wyoming and adjacent States are exposed at the surface.
58 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WY6.

GREYBTTLL FIELD. 

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Greybull oil and gas field (No. 4, PL I), discovered in 1907, 

yields not only a high-grade paraffin, oil but also a large amount of gas. 

The productive area (see fig. 5), which is nearly circular in outline, 

with a diameter of about 2 miles, is fairly well defined by the drill 

holes on the eastern and southern sides. Until recently the oil has 

been transported to refineries in tank cars by the Chicago, Burlington 

& Quincy Railroad, which crosses the central part of the producing 

area, but now it is handled by a refinery, estimated to cost $2,500,000 

and probably large enough to refine the entire production, which 

has just been constructed in Greybull, at the northern edge of the 

field. The gas from this field is used in Greybull for lighting and 

heating.

This field is in the northeastern part of the Big Horn Basin near the 

junction of Greybull and Big Horn rivers in the western part of T. 

52 N., R. 93 W. It is the most easily accessible oil and gas field in 

the State, as no other producing field is crossed by a railroad. The 

most productive wells are within a mile of the railroad station, and 

no part of the proved field is more than 2 miles from the business 

section of Greybull, a town of 600 or 800 inhabitants. Wagon roads 

lead to all parts of the field.

The surface features of the Greybull field consist of broad comparatively shallow trenches worn in the rocks by Big Horn and Greybull 

rivers and of the "terraces adjacent to them. The trenches range in 

depth from 75 feet throughout the greater part of the field to nearly 

300 feet just east of the mouth of Greybull River, and in width from 

half a mile south of the mouth'of Greybull River to 1^ miles just north 

of Greybull. As the terrace west of the river has not been greatly 

dissected by streams the surface on that side of the river is lower and 

much more even than it is east of the stream. For 1£ to 3 miles east 

of the river the surface rock is the thick sandstone which outcrops 

as a conspicuous cliff along the river. (See PL V, A, p. 21.) It 

has been upfolded with the other rocks and its upper surface, which 

has been only slightly worn away, now consists in most places of 

smooth rounded slopes. Northeast of the top of the dome there 

is a structural depression in which a canyon has been cut by an intermittent stream.

The elevation of the surface of the field above sea level is of importance in determining the depth to any particular sand. (See p. 39.) 

It ranges from about 3,775 feet at the northern edge near Big Horn 

River to 4,070 feet at the Wilkinson No. 3 well (No. 43, fig. 5). The
GREYBULL FIELD. 59

highest point in the area represented by figure 5 is about 4,400 feet 

at the southeast corner, but this is outside the oil and gas field.

The Greybull field has an abundance of excellent water during the 

entire year. The waters of Big Horn and Greybull rivers, the only 

perennial streams, can be used for drilling and, except during flood 

seasons when the water is too muddy, for domestic uses. The water 

supply at Greybull is derived from two deep wells situated near the 

river at the northeast edge of the town. Water is found in some of 

the oil wells in the thick sandstone (Peay), which is conspicuous in the 

east bluff near Greybull and on the west side of Big Horn River 

directly south of the refinery, but in some wells it is alkaline and 

sulphurous and hence is not suitable for domestic use or even for 

generating steam. Water is found in some of the sands in which oil 

and gas are absent but the water best suited for use in boilers is 

obtained from the rivers.

The Greybull field is a part of the area examined by Eldridge,1 

Fisher,2 and Washburne,3 of the United States Geological Survey, and 

Hintze,4 of the Wyoming Geological Survey.

STRUCTURE OF THE DOME.

The Greybull dome is an upfold or bulge which has affected all 

of the rocks down to and including the principal oil-bearing sands of 

this region. Its shape and extent are shown in figure 5 by structure 

contours drawn on the Greybull sand. (See p. 57.) It is roughly 

elliptical with its narrow end extending northwest and its broad end 

on the southeast. Its southwest slope is much steeper than any other, 

as indicated by the close spacing of the contour lines on that side. 

The beds are nearly flat at the top of the dome in the NW. i sec. 21. 

They slope gently, not over 3£°, northwest to the end of the dome; 

north, northeast, and east to the depression in the rocks or the syncline separating this dome from the Sheep Mountain anticline; 

southeast to a shallow syncline separating the Greybull dome from 

the Lamb anticline. On the south, southwest, and west sides of 

the dome the beds dip gently to a line about one-half mile from the 

top of the dome; here the dips rapidly increase and reach a maximum 

of 35° in the northwestern part of sec. 19. The depression in the 

rocks or syncline to the northeast of the Greybull dome is comparatively shallow, being about 250 feet in depth.

The cross section (see fig. 5) shows the positions of the rocks as 

they would appear on the sides of a deep trench, if one were cut

» Eldridge, G. H., A geologic reconnaissance in northwest Wyoming: U. S. Geol. Survey Bull. 119, pp. 

64, 65, map, 1894.

* Fisher, C. A., Geology and water resources of the Bighorn Basin, Wyo.: U. S. Geol. Survey Prof. Paper 

53, p. 59, map, 1906.

8 Washburne, C. W., Gas fields of the Bighorn Basin, Wyo.: U. S. Geol. Survey Bull. 340, pp. 348-363, 

map, 1908.

«Hintze, F. F., jr., The Basin and Grey bull oil and gas fields, Bighorn County> Wyo.: Wyoming Geol. 

Survey Bull. 10,1914.
60 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

northeast and southwest across the dome at its highest point. In 

this section the Greybull sand, which contains the oil and gas, is the 

lowest bed represented. At the highest point of the dome it is about 

850 feet below the surface and at the southwest end of the cross 

section about 4,100 feet. This difference in depth is due in part to a 

difference in the surface elevation but more largely to the bulging 

of the strata, which has brought the Greybull sand, as well as other 

formations, nearer the surface at the top of the dome than at other 

places.

Gas is found in the top of the dome and oil in a lower zone on the 

west and northwest sides. Its accumulation there may be due in 

part to the presence of a low wrinkle on the dome, as is suggested by 

the irregularity in the structure contours in the E. | sec. 18, or to the 

presence of water in the Greybull sand close to the gas wells on the 

north, east, and southeast sides. In the writer's opinion the latter is 

the more probable explanation, the water having perhaps pushed the 

oil toward the west and northwest. Water can easily enter the oil 

and gas sand at its outcrop around the south end of Sheep Mountain 

3 to 4 miles north of the Greybull dome. It is well known that water 

in a well will prevent the oil and gas from entering the hole, especially 

when the rock pressure is less than the pressure of the water. Hence 

it seems reasonable to assume that water in the Greybull sand may 

have crowded the oil away from the northeast, east, and southeast 

sides of the dome and confined it to the northwest and west sides, 

where it now occurs.

Faults may have had some effect on the accumulation of oil on the 

west and northwest sides of the dome. Several faults of slight throw 

cut the beds in the north half of the dome, but they can not be traced 

far from the river bluffs. Five of these are shown on the map. 

Others not apparent on the surface are known from well logs to be 

present west of Big Horn River, where the larger part of the surface 

is covered with a veneer of alluvium on the flood plain and of gravel 

on the terrace. They trend northeast and are of the step-fault 

variety, having the downthrow mainly on their northwest sides.

The planes of these faults are cut by several wells drilled in this 

field. Wherever a well cuts the plane of a normal fault the distance 

between recognizable beds is less than where the strata are undisturbed. This condition is illustrated by figure 6. In this ideal 

figure, wells 1 and 3 do not cut the fault plane; but well 2 does, and 

hi it the distance between the two beds of sandstone is less than in 

wells 1 and 3. A careful study of the well logs in the Greybull field 

reveals the fact that the distance between the top of the Peay sand 

and the top of the Greybull sand is in places 170 feet less than normal. 

In wells 3, 5, 14, 23, 26-28, figure 5, the distance between the sands
GBEYBULL FIELD. 61

mentioned is less than normal, and it is therefore believed that the 

wells cut the planes of normal faults. Faults in the midst of a proved 

oil and gas field like the Greybull tend to show that under certain 

conditions sands adjacent to fault planes may become sealed and 

thus prevent the migration of oil and gas into the faults.

At the highest part of the dome the rocks exposed along Big Horn 

River belong to the lower part of the Frontier formation and the 

upper part of the Mowry shale. The prominent sandstone (see PI. 

V, A) exposed in the bluff directly east of Greybull is the Peay sand, 

which occurs in the lower part of the Frontier formation. The base 

of the Peay is about 75 feet above the top of the Mowry shale, which 

outcrops near the water's edge in the western part of sec. 21. The 

Mowry shale is not fully exposed in this vicinity but is shown by

FIGURE 6. Diagram showing the effect of a fault on the apparent thickness of a formation.

many wells to be about 175 feet thick and to embrace two sandy 

beds, the Kimball and Octh Louie sands, which in this field contain 

small quantities of oil. In the Torchlight dome (see pp. 75-81) these 

sands are the principal reservoirs for oil. Underlying the Mowry is 

the dark Thermopolis shale, about 700 feet thick. It contains, about 

300 feet above the base, a very persistent sandstone known as the 

Muddy sand, which contains a little gas. Directly underlying the 

Thermopolis shale is the Greybull sand, which contains the oil and 

gas in the Greybull field. It has an average thickness of about 20 

feet and constitutes the upper part of the Cleverly formation, which 

in this locality is about 115 feet thick.

The logs of one gas well and one oil well are given below in order 

to show the character of the rocks intervening between the surface 

and the Greybull sand, the reservoir of the gas and oil in this field. 

The log of the Minor well (No. 38, fig. 5), the first to find gas, in the 

NW. | NW. I sec. 21, T. 52 N., R, 93 W., is reported by the drillers 

as follows;
62 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO. 

Record of Minor well, Greybull field, Wyofl

Shale, hard, dark; probably the ridge-making layer of the Mowry . ...................

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

Shale, black.. .....................................................:.................

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

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

Thickness.

Feet. 

17 3-4 

300 

3 

127 

40-50 

155 

?1 

49 

1 

49 

7 

38 

5 

20 

5

Depth.

Feet. 

17 

20 

' 320 

323 

450 

495 

650 

651 

700 

701 

750 

757 

795 

800 

820 

825

a Mainly from the log given by Washburne, C. W., Gas fields of the Bighorn Basin, Wyo.: U. S. Geol. 

Survey Bull. 340, p. 352,1908.

The well was drilled originally 801 feet deep, or to the top of the 

Greybull sand. The mouth of the well is about 3,800 feet above sea 

level and would be 165 feet below the base of the Peay sandstone 

were that sandstone extended from its outcrop in the high bluffs 

east of the river to the vicinity of the well.

The Meade No. 1 well (No. 8, fig. 3) of Bighorn Oil & Gas Co., in the 

SE. I NE. 1 sec. 17, T. 52 N., R. 93 W., is near the refinery but on 

the east side of the railroad, in Greybull. The log follows:

Record of Meade No. 1 well, Greybull field, Wyo.

Feet.

Top of Muddy sand.............................................. 583

Top of Greybull sand (contains oil)............................... 915

Bottom of Greybull sand (bottom of hole)......................... 935

The mouth of this well is 3,810 feet above sea level. Water was 

encountered down to a depth of a little more than 100 feet and was 

cased off at 115 feet.

DEVELOPMENT.

The first well in this field (Minor No. 38) was drilled in July, 1907, 

and produced only gas, whose initial flow has been estimated at 

8,000,000 to 10,000,000 cubic feet daily. The gas became accidentally ignited soon after the well was completed and burned for 

more than a year and a half. Fifteen months after this first well was 

drilled a well (the George Alford No. 1, No. 40 on fig. 5) yielding highgrade oil and a little gas was brought in. Since 1908 about 70 wells 

have been drilled in this field, mainly by the Bighorn Oil & Gas Co., 

of Greybull. The following table, complete up to October 10, 1915, 

shows considerable data regarding the development of the field. If 

a well yields neither oil nor gas in commercial quantities it is shown
GBEYBULL FIELD. 63

on the map as a dry hole. In this table if it contains water, but no 

oil or gas, "Water" is placed in the "Result" column. If it yields 

neither oil, gas, nor water, "Dry" is placed in the "Result" column.

Wells in T. 52 N., R. 93 W., of Greybull field, Wyofl

No. 

on 

map 

(flg.5, 

p. 57)

1

4

5

7

8

10

11

19

13 

14 

15 

16

17

18

19 

20

91

99

9^>

24

25

oo

27 

28 

29

30 

31

32

34 

35

36 

37 

38 

39 

40

41

42 

43

Name.

1\T 1n Mn 1

school section. 

StubbsNo. 2.....

StubbsNo. 1.....

StubbsNo. 3.....

No. 2.

(?)...............

No. 1.

No. 3.

Island No. 5...... 

Stony Point...... 

Brickyard No. 1.- 

Rubel.... ........

pleted). 

JuellNo. 1. ......

Ohio Oil Co. No... 

(?)...............

No. 3. 

Thomas Alford 

No. 1. 

Thomas Alford 

No. 3.

No. 2. 

Thomas Alford 

No. 4. 

George Alford 

No. 4. 

George Alford 

No. 2. 

Island No. 3...... 

Island No. 4......

Island No. 2......

Armstrong No. 1 . Wilkinson No. 4..

Armstrong No. 2. 

Durham No. 1. .. 

Minor............ 

Homestead No. 1 

George Alford 

No. 1.

Wilkinson No. 1.. 

Wilkinson No. 2..

Owner.

Gas Co. 

.....do..........

Co. 

.....do..........

.....do..........

Gas Co. 

.....do..........

.....do... .......

.....do . ......

.....do..........

.....do..........

.....do..........

.....do.......... 

.....do ....... 

.....do.......... 

.....do..........

.....do..........

.....do..........

Ohio Oil Co.... 

(?).............

Bighorn Oil &

Gas Co.

Co.

Gas Co. 

.....do .......

.....do.......... 

.....do .......

.....do.......... 

.....do ...... 

.....do..........

.....do ...... 

.....do .......

.....do .......

.....do ...... 

.....do ......

.....do ...... 

.....do ....... 

.....do ...... 

.....do ....... 

.....do .......

.....do..........

.....do.......... 

.....do .......

Result. &

Water.........

.....do. ....-

Oil............

A little oil.....

Oil............ 

Dry...........

Oil............

.....do. ....-

Gas and a little oil. 

Gas...........

.....do.........

Water.........

Oil............ 

.....do......... 

Dry...........

Oil............

Dry........... 

(Oil reported

in Kunball 

sand.) 

Oil............

Water.........

Oil............

.....do......... 

.....do......... 

.....do.........

.....do......... 

.....do......... 

.....do.........

.....do ...... 

.....do ......

Gas and a little oil. 

Gas........... 

.....do.........

.....do ....- 

.....do ...... 

.....do ....- 

.....do ...... 

Oil............

.....do .....

Gas........... 

.....do ......

Depth 

to Greybull 

sand.

1,092

1,114

971

970

9SO 

1,100±

940±

915

882

1,060

1,066

1,043

879 

977 

1,730 

(°)

<<)

1,795

1,700 

(?)

1,260

1,185

1,080

1,140 

1,255 

1,125

1,115 

1,035 

975

897 

899

880

1,075 

852

1.075 

1,072 

825± 

841 

887

944

815 

1,067

Date drilled.

1911. 

(?).............

.....do..........

.....do. . 

May, 1910......

Sept., 1915......

Mar., 1910......

Nov., 1910 ...

(?).............

m. ............

Aug., 1909......

Sept., 1914 ... 

Mar., 1909...... 

Mar., 1910......

1914.

Mar. and Apr., 

1911. 

Sept., 1915..... 

(?)............-

Ana iQin

Mar., 1914......

1914. 

Sept., 1909 ..

May and June, 

1915. 

Mar., 1915......

June and July, 

1915. 

.....do ......

Aug. and Sept., 

1909. 

Aug., 1914...... 

Aug. and Sept., 

1914. 

Feb., 1909......

May, 1909...... 

Oct. and Nov., 

1912. 

Oct., 1912...... 

May, 1909...... 

July, 1907...... 

Feb., 1910...... 

Oct., 1908......

(?).............

Jan., 1910....... 

Sept., 1910......

Location.

SW. J SE. J sec. 5.

1MW 1 <3W 1 «p/» Q

NE.JNE.Jsec.17.

Do.

NW.jNE.Jsec.17. 

NW.JNW.Jsec.16.

NE.iNE.Jsec.17.

Do.

SW.JNW.Jsec.16.

Do.

NW.JSE.Jsec.16.

SE.JNW.Jsec.15.

SW.JNW.Jsec.16. 

SW.JNE.Jsec. 17. 

SE.JNE.Jscc. 18. 

SW.JNE.Jsec. 18.

SE.JSE.Jsec.18.

Do. 

NW.J NW.J sec. 20.

NE.JNW.Jsec.20.

NW.JSE.Jsec.20.

NW.jSE.Jsec.17.

SE.JSW.Jsec. 18. 

SE.JSW.Jsec. 17. 

Do.

Do. 

SW.J SE.Jsec. 17. 

Do.

SW.JNE.Jsec. 17. 

NE.JSE'.Jsec. 17.

Do.

NE.JSW.Jsec.16. 

SW.J SW.J sec. 16.

SW.J SE.Jsec. 16. 

NW.JNE.Jsec.21. 

NW.JNW.Jsec.21. 

SW.J SW.J sec. 16. 

SE. J SE. J sec. 17.

NE.JNE.Jsec.20.

SW.JNW.Jsec.21. 

SE.jNW.Jsec.21.

a About 20 additional wells were drilled on this dome between Oct. 10,1915, and Apr. 1,1916, 

t> The results given in this column pertain to the Grey bull sand only. 

«Not reported.,
64 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO. 

Wells in T. 52 N., R. 93 W., of Greybull field, Wyo. Continued.

No. 

on 

map 

(flg-5, 

p. 57).

44

45 

46

47

48

40

50

51

52

53

Name.

WilkinsonNo.3.. 

Durham No. 2. . .

No. 1.

Skinner No. 1 ....

Owner.

Gas Co. 

.....do.......... 

.....do..........

.....do..........

.....do..........

....'.do..........

Okla. 

Bighorn Oil &

Gas Co.

Oil Co. 

.....do..........

Result.

Oil............

A little gas.... 

Gas...........

Dry...........

Water.........

.....do.........

Depth 

to Greybull 

sand.

854

1,065 

1,078

1,070

1,116

1,197

936

952

(a)

1,200

Date drilled.

Aug., 1912......

Sept., 1912...... 

Sept. and Oct.. 

1912. 

July, 1909......

June, 1910......

July, 1910...... (?):............

Feb., 1910......

(?).............

(?).............

Location.

NW.iSW.Jsec.21.

NW.JSE.Jsec.21. 

SW.JNE.Jsec.21.

NW.JSE.Jsec.21.

&W i TVTW 1 cpn 99

NW.JSW.lsec.22.

SW.iSW.Jsec.21.

NE.JNE.isec.28.

NW.iSW.isec.28.

NE.JSW.Jsec.28.

a Not reached.

During the summer and autumn of 1915 an impetus was given to 

drilling operations by the discovery in Greybull of larger oil wells 

than any previously known in this field. Some of these wells are 

reported to have at first yielded as much as 500 barrels daily, but the 

production is said to have dwindled to about 100 barrels daily after 

they had been pumped for a few weeks and to have diminished 

greatly since that time.

It is estimated that the daily oil production of the Greybull field 

on October 1, 1915, was 1,500 barrels, or at the rate of slightly more 

than a half million barrels annually. On April 1, 1916, the production was estimated to be 3,000 to 4,000 barrels daily, but in the fall 

of 1916 it had declined greatly.

QUALITY OF OIL AND GAS.

The oil is high grade and has a paraffin base. In reflected light it 

has a dark-green color and in transmitted light a dark wine color. The 

specific gravity of the oil is 0.7856 or about 48° Baume". An analysis 

made by the Bureau of Mines of a sample of oil collected from the 

George. Alford No. 1 well (No. 40, fig. 3) in this field is as follows:

Analysis of oil from George Alford No. 1 well, in the SE. £ SE. £ sec. 17, T. 52 N.,

R. 93 W.

Began to boil at 30° C.

Gasoline: Percent. 

To 50° C.......:......................................... 3.5

50° to 75°................................................ 4

75° to 100°............................................... 7.5

100° to 125°.............................................. 9

125° to 150°....-......,,.,,,,,,..,,.,,,.,................ 7

31
GEEYBTJLL FIELD. 65

Kerosene: Percent.

150° to 175°.............................................. 6

175° to 200°.............................................. 5

200° to 225°.............................................. 5

225° to 250°..........................-................... 5

250° to 275°.............................................. 5

275° to 300°.............................................. 6. 5

32.5 

Eesiduum........... . ........................................ 36.5

Sulphur...................................................... .04

Specific gravities at 60° F.:

Crude oil (48.2° Baume")..................v............... 0.7856

Gasoline (66.6° Baume").................................... . 7120

Kerosene (47.2° Baume")................................... .7900

Residuum.(33.2° Baume").................................. . 8579

A sample of gas (laboratory No. 6851) from the Thomas Alfred 

No. 1 well (No. 24, fig. 5), in the SE. \ SW. | sec. 17, T. 52 N., R. 

93 W., was analyzed by the Bureau of Mines. The analysis shows a 

high percentage of nitrogen and much oxygen, suggesting that the 

bottle in which the gas was collected must have contained some air 

with the gas, because in the analyses of samples of natural gas collected from the Greybull field by W. R. Calvert * the oxygen content 

is zero and the maximum nitrogen content 1.25.

Analysis of natural gas from Thomas Alfred No. 1 well, in the SE. %SW. % sec. 17, T. 52

N., R. 93 W.

[G. A. Burrell, analyst.] 

Specific gravity (air=l)....................................... 0.85

Carbon dioxide (C02).......................................... .10

Oxygen (Oa)........................'........:................ 3.20

Methane (CH4 )................................................ 38. 70

Ethane (C2H6)............................................... 42. 50

Nitrogen (N2)................................................ 15.50

100.00

The heating value of this gas at 0° C. and 760 millimeters pressure (calculated) ia 

1,203 British thermal units.

The analysis by the Bureau of Mines of a sample of gas collected 

by W. R. Calvert* from Island No. 1 well (No. 9, fig. 5) is given 

below:

i Calvert, W. R., A preliminary report on the utilization of petroleum and natural gas in Wyoming: 

Bur. Mines Tech. Paper 57, p. 13,1913.

86133° Bull. 656 17 5
66 ANTICLINES IN SOUTHERN PART OF BIG HORN B, .*%* WYO.

Analysis of natural gas from Island No. 1 well, in the SW. J NW. £ sec. 16, T. 52 N.,

R. 93 W.

[Laboratory No. 3224. 0. A. Burrell, analyst.] 

Specific gravity.............................................. 0.64

Carbon dioxide (C02).......................................... .20

Oxygen (02)................................................. .00

Methane (CH4 )................................................ 81.70

Ethane (C2H6).................'.............................. 17.35

Nitrogen (N2 )..:........................................ v.... .75

100.00 

CONCLUSIONS.

The productive and possibly productive areas of the Greybull field 

are limited definitely in places by dry holes. This is particularly 

true of the southern part, where dry wells 22, 45, 47, 50, and 51 are 

near productive wells 43,44, and 46. It is probable that wells drilled 

within one-fourth mile southwest, south, southeast, and east of well 

44 may yield some oil, but it is doubtful if the quantity will be large. 

Little gas will be found in this locality unless faults or some other 

factor not noticeable on the surface create conditions favorable for 

its accumulation. Dry holes (48 and 49, in the W. $ sec. 22) limit 

the field to the southeast. Possibly other gas wells or small oil wells 

may be found as far as one-fourth mile east of wells 36, 37, and 46. 

Well 48 showed a trace of oil which suggests that more may be found 

farther up the 'slope of the dome or to the west and northwest. 

Between the synclinal axis and wells 10,11, 34, and 36 oil and gas wells 

of slight production may be brought in.

The west side of the dome is the most promising for future development. The recent discovery of oil in wells (Nos. 3, 4, 5, and 7) in 

the northeastern part of sec. 17 suggest that the oil pool may extend 

north nearly to the synclinal axis. The position of oil wells Nos. 

23-28, inclusive, hi the southern part of sec. 17, and No. 18 hi the 

southeastern part of sec. 18, indicates that the west boundary of the 

oil-producing territory may follow the 2,400-foot structure contour 

from a point near the synclinal axis south to a point east of dry hole 

15. From this point it probably swings west and south around wells 

18-21, and thence goes nearly east, keeping north of well 22 to the 

line A-B (fig. 5, p. 57), and thence southeast^ to a point midway 

between wells 22 and 44, there connecting with the line above described. 

Well 19, belonging to the Ohio Oil Co., is reported to be absolutely 

dry, this suggesting that the productive area is "spotted."

The northwest boundary of the field, as indicated above, has not 

Ibeen determined. It seems probable to the writer that the productive area extends farther toward the southwest than in any other 

direction, because in this field the best wells seem to be associated 

with faults and the fault zones trend northeast-southwest. At the
GREEK DOME AND CHEERY ANTICLINE. 67

northeast the field is limited by the synclinal axis. The presence of 

dry holes 15 and 16 on the north and 22, 50, and 52 on the south of 

oil wells 17-21 indicates that the productive belt extending to southwest is about a mile in width. It seems doubtful if the productive 

territory extends far southwest of well 20.

Close drilling within the area outlined above may increase the 

present output of oil, but the enormous amount of gas that escaped 

from the Minor well in 1907 and 1908 has so reduced the pressure 

and quantity that it seems doubtful whether the production of gas 

will be greatly increased by further drilling.

SHELL CHEEK DOME AND CHERRY ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Shell Creek dome (No. 2, PI. I) and the Cherry 'anticline (No. 

3, PI. I) are closely connected upfolds in the drainage basin of Shell 

Creek, about 8 miles northeast and east of Greybull, a town of 600 or 

800 inhabitants on the Chicago, Burlington & Quincy Kailroad. 

The She'll Creek dome has been fully tested for oil and gas, with negative results. The Cherry anticline has been tested by one well, which 

presumably penetrated the Embar formation, in this locality the 

most promising reservoir for oil and gas. According to report, oil 

was thought to have been found in this formation, but the quantity 

must have been so small as to be negligible. As the probability of 

obtaining oil and gas in these upfolds is extremely doubtful, their 

descriptions will necessarily be brief. They are considered together, 

as, they are closely related structurally.

The Shell Creek dome lies in sees. 29-32, T. 53 N., R. 92 W., and 

the Cherry anticline mainly in sees. 3-5, 8-10, T. 52 N., R. 92 W., 

about 2£ miles southeast of the Shell Creek dome and 8 miles east of 

Greybull.

Both anticlines are easily accessible, as a good road leading from 

Greybull to Shell, a town on Shell Creek near the west base of the 

Big Horn Mountains, follows in general the course of Shell Creek and 

lies between the two folds. Numerous secondary roads enable one 

to examine both areas with comparative ease.

The principal surface feature in this locality is the valley of Shell 

Creek, which crosses the south edge of Shell Creek dome. The surface 

along the crests (formerly called axes) of the anticlines is characterized 

by basin-like depressions, formed by the wearing away of the soft rocks 

by streams tributary to Shell Creek, surrounded by low walls of 

variegated sandstone and shale. In places, particularly along the 

west side of the Cherry anticline, long, straight, narrow hogbacks 

trend northwest. At many places along the smaller tributary
68 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

streams and particularly near their heads badlands make travel 

difficult.

The water supply o of both anticlines is abundant, as Shell Creek 

crosses Shell Creek dome, and an irrigation canal from Shell Creek, 

8 or 10 miles distant, crosses the Cherry anticline near its middle. 

Water from this canal and from Shell Creek is used for drilling, 

camp, and domestic purposes. Water was also found, according to 

report, in the well drilled in the Shell Creek dome, being probably 

derived from some of the sands in the Chugwater formation ("Red 

Beds"), which overlie the limestone in which the oil and gas were 

thought to occur.

SHELL CREEK DOME.

The Shell Creek dome is elliptical in outline and trends northwest 

and southeast. Its steepest slope is on the southwest side, where 

the beds dip as much as 25°. At the south end of the dome the beds 

dip gently southeast into the low sag separating the dome from the 

Cherry anticline. On the northeast side of the Shell Creek dome the 

beds are much more nearly flat than they are on the southwest side, 

ranging from zero on the crest to about 9° one-half mile distant. 

From this region they gradually flatten to 2° in the NW. I sec. 29, 

T. 53 N., R. 92 W. On the northwest side of the dome the beds dip 

slightly for 2 miles to a shallow syncline or depression in the rocks 

that separates the Shell Creek dome from the large anticline of Sheep 

Mountain (No. 1, PL I).

The lowest rocks exposed in this dome belong to the Morrison formation, which consists of 200 to 300 feet of variegated shale and 

sandstone. Overlying the Morrison is the Cloverly formation, about 

125 feet thick, which consists of an upper sandstone the Greybull 

sand which carries the oil and gas in the Greybull field. Underlying this bed there are about 75 feet of variegated shale, mainly red 

in color, and underlying this shale is a conglomeratic sandstone about 

25 feet in thickness. Overlying the Cloverly formation and surrounding the dome on the southwest and northeast is the Thermopolis 

shale, a dark bluish-gray shale 600 or 700 feet thick with a sandstone 

bed (Muddy sand) about 275 feet above its base. This sand is not 

known to contain oil or gas in commercial quantities except in the 

Oregon Basin (p. 185).

Directly underlying the Morrison formation, the upper part of 

which constitutes the surface rocks at the top of the dome, is the 

Sundance formation, about 300 feet thick, consisting mainly of lightgreen sandstone and shale. Below these rocks is the Chugwater 

formation ("Red Beds"), 900 to 1,000 feet thick, and directly underlying the Chugwater is the Embar formation, embracing the limestone in which oil and gas were thought to occur in this locality.
U. S. GEOLOGICAL SURVEY 

R.93VV. R.92W.

BULLETIN 656 PLATE VII

R.9IW.

LEGEND

Crest of anticline $ Dry hole

Axis of syncline

Structure contours (tines of equal altitude) on top 

of Greybull sand. Numbers show distance above 

or below sea level. Solid lines indicate present 

position of sand below, and broken lines former 

position above present 'surface, Interval 2OO feet

Scale 

Q____ i 2 MILES

STRUCTURE CONTOUR MAP OF SHELL CREEK DOME AND CHERRY ANTICLINE

(Nos.-2.AND 3, RESPECTIVELY, ON PLATE I)

The outcrops of sands are mapped as sandstones

By Charles T. Lupton
SHELL CEEEK DOME AND CHEEKY ANTICLINE. 69

The structure contours drawn on the top of the Greybull sand (top 

of the Cloverly formation) show the shape and extent of the Shell Creek 

dome. (See PI. VII.) From these and from the surface elevations, 

which range from about 3,925 feet in the SW. J sec. 31, T. 53 N., 

R. 92 W., to about 4,550 feet near the center of sec. 11, T. 52 N., 

R. 92 W., the approximate depth to the top of the Greybull sand or 

to any other sand whose relation to the Greybull is known may be 

determined. (See pp. 39-41.)

CHEERY ANTICLINE.

The Cherry anticline is a northwestward-pitching wrinkle on the 

west flank of the Big Horn Mountains. It is unsymmetrical, with 

its southwest limb narrower than its northeast limb. The beds on 

this flank at points about a mile from the crest, however, have an 

average dip of 42° and attain a maximum dip of 50° in the SE. | 

sec. 15, T. 52 N., R. 92 W. The dips decrease to zero at the crest 

of the anticline and also in the opposite direction to the axis of the 

syncline separating this anticline from that of Greybull dome to the 

southwest. A mile or more southeast of the Cherry well the pitch 

of the anticline to the northwest is less than it is farther southeast, 

thus forming a terrace-like structure.

The lowest rocks exposed along the crest of the anticline belong 

to the upper part of the Sundance formation, which, with other 

formations outcropping and lying beneath the surface in this locality, 

as well as the structure contour, are described in connection with the 

Shell Creek dome (p. 67). (See also p. 18.) 

DEVELOPMENT.

Two wells have been drilled on these anticlines. One, the Nicholson well, near the center of Shell Creek dome, in the SW. J NE. \ 

sec. 31, T. 53 N., R. 92 W., is about 2,000 feet deep and is reported 

to have .penetrated the Embar formation, which was thought to have 

contained oil or gas. Its mouth is about 3,975 feet above sea level. 

The other, the Cherry well, on the Cherry anticline, in sec. 10, T. 52 N., 

R. 92 W., is well located near the crest line of the anticline and is 

reported to have reached a depth of about 700 feet but found no oil 

or gas. According to careful estimates, the drill did not reach the 

limestone but went only a little more than halfway through the 

Chugwater formation ("Red Beds"). Its mouth is about 4,100 feet 

above sea level. .Both wells were drilled during the spring and 

summer of 1915, that on the Shell Creek dome by 0. W. Nicholson, 

of Basin, Wyo., and that on the Cherry anticline, according to report, 

by Scott Mills, of Basin, Wyo., for the Cleveland-Wyoming Oil Co.
70 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

CONCLUSIONS.

As the Shell Creek dome has already been tested by a well at the 

top of the dome and found not to be a reservoir for oil or gas, further 

drilling is inadvisable. The Cherry anticline has not been thoroughly tested, but the presence of water in the Shell Creek dome and 

the general northwesterly pitch of the Cherry anticline make the 

occurrence of oil or gas in commercial quantities doubtful. Hence, 

the writer advises against the expenditure of more money in further 

attempts to test either anticline.

LAMB ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Lamb anticline (No. 5, PI. I) and Torchlight dome are shown 

on the same map (PI. IX, p. 78), as they are very closely related 

structurally.1 They are, however, described separately.. The Lamb 

anticline yields not only large quantities of gas from wells drilled 

near the crest line but also some heavy lubricating oil. The productive area of this anticline has not been definitely outlined by 

wells except on the east and south. To the west and northwest there 

is a broad area a mile or more in width and about 2 miles in length 

in which no wells have been sunk. The anticline may yield some 

gas and probably considerable oil of a type heavier fhan that found 

in Torchlight dome.

The Lamb anticline is about 3£ miles northeast of Basin and 

about the same distance from the south edge of the Greybull field. 

It lies principally in sees. 7, 17, and 18, T. 51 N., R. 92 W., and sees. 1, 

2, 11-14, T. 51 N., R. 93 W. It can be reached most easily from 

Basin, on the Chicago, Burlington & Quincy Railroad, from which 

place good roads to all parts of the anticline make easy the transportation of machinery and supplies.

The central part of the anticline is represented on the surface by 

a depression formed by the wearing away of the rocks by a small 

intermittent stream, which after flowing south through Torchlight 

dome empties into Big Horn River in the western part of sec. 26, 

T. 51 N., R. 93 W. The walls of this basin-like depression consist 

of ridges of shale from 200 to 400 feet in height. In places, especially 

on the eastern side of the anticline, these inward-facing walls of shale 

are very steep, and near the heads of gulches the slopes have been 

cut into typical badlands, across which it is almost impossible to 

travel except on foot. The high ridge on the west whose eastern

i A more complete description of these anticlines is given in U. S. Geol. Survey Boll. 621, pp. 167-100, 

1916.
LAMB ANTI0LINE. ?1

slope is more gentle than its western, separates the depression from 

the flood plain of Big Horn River; and the ridge on the east slopes 

gently and merges with the broad rolling country which constitutes 

the greater part of the area between the anticline and the southwest 

base of the Big Horn Mountains. /

The surface elevations range from about 4,150 feet in the SE. £ 

sec.'12, T. 51 N., R. 93 W., to about 4,550 feet near the north quarter corner of sec. 11 of the same township. From these elevations 

the approximate depths to the various sands may be calculated. 

(See p. 39.)

The main water supply comes from well No. 18 (Columbia No. 1) 

in the SE. £ NE. | sec. 12, T. 51 N., R. 93 W., which produces fresh 

water from the lower part of the Peay gas sand. It is pumped to 

the Torchlight camp 2£ miles to the south for domestic purposes. 

Water has been found in this sand by many of the wells on the 

anticline, but in none of them is it known to be so fresh as in Columbia No. 1. An almost inexhaustible supply of water is found 

the year round in Big Horn River, 3 miles to the west. At no time 

since the discovery of fresh water in Columbia No. 1, however, has 

water been derived from this source for drilling or camp purposes in 

the Lamb anticline. A few reservoirs, made in this general locality, 

to catch and hold the surface run-off, have all been successful, as the 

water in them does not escape easily through the dense shale.

STEUCTTJRE.

The Lamb anticline is about 5 miles in length and trends in general 

northwest, but its crest line is curved, with the concave side facing 

the northeast. The beds dip more steeply on the northeast flank 

of the anticline than in any other part, reaching a maximum of 10° 

at a point about half a mile northeast of the axis in the SW. £ sec. 7, 

T. 51 N., R. 92 W. From this point northeastward the dip is less 

for a mile or more, beyond which it increases again to flatten once 

more west of the axis of the syncline separating this structure from 

the southeast extension of the Cherry anticline. (See PI. VII.) The 

beds at the southeast end of the anticline do not dip more than 5° 

but become steeper near the synclinal axis separating the Lamb 

anticline from the Torchlight dome. To the west the dips are gentle 

(not exceeding 5°) for 2 miles from the crest line, beyond which 

they increase rapidly. To the northwest the dips are very gentle, 

not exceeding 1$° at any known point south of the south boundary of sees. 35 and 36, T. 52 N., R. 93 W.

A shallow structural sag separates the northwest end of the Lamb 

anticline from a small dome about a mile in diameter which lies in 

sees. 30 and 31, T. 52 N., R. 92 W., and sees. 25 and 36, T. 52 N., 

R. 93 W. The beds dip as much as 3 q northwest of well No. 24 in
72 ANTICLINES IN SOUTHERN PAET OF BIG HORN BASIN, WYO.

the southern part, of sec. 25, T. 52 N., R. 93 W. A shallow cross 

syncline lying northwest of the Lamb anticline and of the small 

dome which constitutes its northeast extension separates the two 

from the Greybull dome.

The structure contours drawn on the Greybull sand show approximately the shape and position of the anticline. Those for the north 

end shown on Plate IX differ from those for the same locality shown 

on Plate XVIII of United States Geological Survey Bulletin 621, 

the positions on Plate IX being based on more detailed examinations. 

The cross section on the map (PL IX) represents the shape of the 

Lamb anticline and of the southern end of the Torchlight dome.

The surface rooks of Lamb anticline consist of the dark-gray Cody 

shale, which is a little over 3,000 feet thick and contains a few sandstone beds near the top and one near the base. None of these sandstones are exposed in or around the Lamb anticline, except the 

lower lenticular bed, which outcrops a mile farther south in the 

Torchlight dome, and the upper beds which outcrop 2 or 3 miles 

farther south.

The rocks directly underlying this shale compose the Frontier formation and consist of about 550 feet of beds of sandstone separated 

by sandy shale and clay. Two sandstones are present in this formation an upper one, known as the Torchlight sand, found at a 

depth of about 160 feet below the surface in Columbia No. 1 well 

(No. 18 on PI. IX), and a lower and thicker one, known as the Peay 

sand, about 400 feet lower. It is this lower sand that contains the 

gas and some of the oil. Directly underlying the Peay sand 75 to 

100 feet of shale, similar to that found between the Torchlight and 

Peay sands, constitutes the lower part of the Frontier formation. 

The rocks directly below the Frontier formation the Mowry shale 

consist of 160 feet of hard, dark-gray platy shale, with two or more 

sandy beds, characterized by large numbers of fish scales. The 

uppermost of the sands is known as the Kimball, and the other, 

about 50 feet lower, as the Octh Louie. Both of these sands and 

the intervening shale are known to contain oil in the Torchlight dome 

but contain little in the Lamb anticline. Below the Mowry shale 

there is about 700 feet of dark shale, known as the Thermopolis shale, 

which contains a bed of sandstone (Muddy sand) 10 to 20 feet thick 

about 300 feet above its base. The Muddy sand is not known to 

carry oil or gas in commercial quantities except hi the Oregon 

Basin. (See p. 181.) Directly below the Thermopolis shale is the 

Cloverly formation, about 125 feet thick, the top sandstone of 

which (Greybull sand) carries the oil and gas in the Greybull field. 

It is uncertain, however, whether or not it contains oil in this field, 

as it has never been tested except at well No. 24 in sec. 25, T. 52 N., 

R. 93 W., where it is dry. In the Torchlight dome a mile or more 

to the south two wells to the Greybull sand found water, proving
LAMB ANTICLINE. . 73

almost conclusively that oil and gas are lacking in the Greybull sand, 

in the Torchlight dome, and probably in the Lamb anticline. . The following logs of wells drilled hi the Lamb anticline are given 

to show the depths to the sands that contain oil, gas, and water:

Log of Lane No. 1 well (No. 23, PL IX), SE,'$SE. i sec. 12, T. 51 N., R. 93 ,W.

Feet. 

Top of Torchlight sand......................................... 5 i

Shale, sandy, dark.............................................. 200±

Top of stray sand; contains a'little gas.......................... 225

Shale, dark, sandy............................................ 200±

Top of Peay sand; contains much gas............................ 435

Bottom of hole............................................... 445

Log of Ruth well (No. 24, PI- IX), SW. i SE. £ sec. 25, T. 52 N., R. 93 W.

Feet. 

Top of Peay sand; contains water.. ............................ 940

Top of Kimball sand, dry.:.................................... 1,140

Top of Muddy sand; shows a little gas.......................... 1,735

Top of Greybull sand; dry..................................... 2,060

Bottom of hole.................................:............... 2,100

DEVELOPMENT.

Thirteen wells have been drilled in the Lamb anticline, seven of 

which are dry,1 two yield oil, and four gas. The first well, No. 29, 

was drilled on the edge of this anticline in 1907 by the Union Oil & 

Gas Co. A little gas was found but not enough to encourage further 

drilling, and no other development work was done until November or 

December, 1913, when Lane No. 1 well (No. 23, PL IX) near the crest 

was drilled to the Peay sand. A large amount of gas was found, 

the original flow according to information from H. T. Lamb, manager of the Greybull Oil Co., being 5,000,000 cubic feet daily. The 

average rock pressure at present is said to be about 145 pounds. 

The well was not drilled entirely through the sand, but it is doubtful if further drilling would have obtained a greater flow of gas. 

Near the crest line of the anticline the Peay sand is entered by the 

drill at a depth of 450 feet, but,this depth increases with the distance from the crest line. The accompanying table furnishes information regarding the wells drilled on this anticline:

1 The term "dry" as used to this report means, unless otherwise explained, barren of oil and gas in 

commercial amounts.
TFeZZs in Lamb anticline.

No. 

on 

map 

(PL IX).

15 

16 

17 

18 

19 

20 

21

22 

23 

24 

25 

28 

29

Name.

Ruth.......................

Union Oil & Gas Co. well. ..

Owner.

Greybull Oil Co .............

.....do......................

.....do......................

.....do......................

.....do.....................'.

.....do......................

.....do......................

.....do......................

.....do......................

.....do......................

Result.o

Water......................

/Oil in Kimball.. ............

\Water in Peay . . ............ 

Gas.........................

.....do......................

Water......................

Water and a showing of oil. .

Depth 

to 

Peay 

sand.

Feet. 

670 

735

630 

770 

840

} 630

550 

440

(b ) 

440

Ap

De

TII

De

No

De

M

19

The results given in this column pertain only to the Peay santi. 
TORCHLIGHT DOME. 75

The gas from Wells Nos. 18, 22, and 23 is piped to Basin and 

Greybull for domestic use. The oil in wells Nos. 20 and 21 is not 

being utilized. It is doubtful if drilling will be continued in this 

anticline outside the tracts now being drilled until a leasing law 

has been passed by Congress, as the area including the anticline is, 

for the most part, withdrawn from entry by the Government.

. CONCLUSIONS.

Dry holes (Nos. 15-17, 19, 24, 25, 28, and 29) define in a very 

general way the outline of the productive area of the Lamb anticline. It seems very doubtful if oil and gas wells of importance 

will be discovered at any place more than one-fourth mile east and 

northeast of the crest line. The presence of dry holes Nos. 15 and 

25, both of which are near the southeast end of the crest, suggests 

strongly that this part of the anticline is barren of both oil and gas 

in commercial quantities. The same is probably true of the area 

lying south and west of both of these wells, at least as far as the 

synclinal axis separating the Lamb anticline from Torchlight dome. 

It seems reasonable to assume that the area for more than a mile 

west of wells Nos. 18,19, 22, and 23 is worthy of investigation. The 

presence of an oil well (No. 21) at a point nearly a mile west of gas 

well 23 suggests strongly that the intervening area, as well as an 

area lying one-fourth to one-half mile west of well 21, may contain 

oil. Gas wells are likely to be found adjacent to the crest line of 

the anticline north and northwest of well 23. It is questionable 

if the gas-bearing area is more than three-fourths of a mile to 1J 

miles in length from northwest to southeast or more than one-half 

to three-fourths of a mile wide from northeast to southwest.

TORCHLIGHT DOME.

By CHARLES T. LUPTON.

GENERAL FEATURES.

A high-grade paraffin oil and a little gas are produced from the 

Torchlight dome (No. 6, PI. I), which within certain boundaries is 

a good producer.1 The oil is obtained from the Kimball and Octh 

Louie sands of the Mowry shale and is reached by the drill at depths 

ranging from 400 to 600 feet.

The Torchlight dome is about 3 miles east of Basin a town of 

about 1,000 inhabitants with which it is connected by good roads. 

The dome lies principally in sees. 19 and 30, T. 51 N., R. 92 W., 

and in sees. 13, 14, 23-25, T. 51 N., R. 93 W.

1 A more complete description of this dome and of the Lamb anticline is given in U. S. Geol. Survey 

Bull. 621, pp. 157-190,1916.
76 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

The surface of the dome is characterized by a basin-like depression 

eroded in shale and surrounded by nearly concentric inward-facing 

walls with shale above and sandstone below. In places the basinward slopes are cut into badlands. This depression, which in places 

is 300 feet deep, has been formed mainly by the wearing away of 

the rocks by a stream, which begins near the north end of the Lamb 

anticline, flows along the crest of that upfold for more than 3 miles, 

crosses through the center of the Torchlight dome, and joins Big 

Horn River about 2 miles southeast of the town of Basin. The 

depression of the surface directly on the upfold of the rocks is shown 

in the cross section (PI. IX).

The surface elevation ranges from about 4,000 feet above sea level 

at well 14, in the southern part of sec. 25, T. 51 N., R. 93 W., to about 

4,450 feet near the east quarter corner of sec. 19, T. 51 N., R. 92 W. 

The elevations of the structure contours subtracted from the surface 

elevations give the approximate depths to the Greybull sand on 

which the structure contours are drawn.

The water supply in an oil and gas field in a semiarid region is an 

important factor in development. In this part of the Big Horn Basin 

the rainfall is unusually small, being about 6 inches annually. At 

present the main supply is derived from Columbia No. 1 well (No. 18, 

PL IX) situated on the Lamb anticline, 2 or 3 miles to the north of 

the dome. Fresh water from this well is pumped to a large reservoir 

and tanks in the central part of the Torchlight dome. A few reservoirs to catch surface water have been made and afford an additional 

supply for drilling purposes. In some of the sands, particularly the 

Peay, water is found, which lessens the quantity that must be pumped 

or brought from other places for drilling. Most of it, however, is 

sulphurous. Previous to the discovery of fresh water in the Columbia 

No. 1 well (No. 18, PL IX), water for domestic and drilling purposes 

was pumped or hauled from Big Horn River.

STRUCTURE.

The Torchlight dome is an elliptical upfold in the rocks trending 

northwest, with its broad end facing southeast. It is about 3 miles 

long and 2 miles wide, and is separated from the Lamb anticline,by a 

shallow syncline, a depression in the rocks 200 to 300 feet deep. 

Along the crest of the dome the beds lie nearly flat, dipping gently 

outward. On the north limb the maximum dip (11°) of the rocks is 

reached about one-fourth mile away from the crest line; beyond this 

the beds gradually flatten to the axis of the syncline. The dips are 

comparatively low, averaging 3° to 4° at the northwest and southeast 

ends of the dome. On the southwest the beds gradually increase in 

dip from zero at the crest line to 25° near Big Horn River. The dip 

is comparatively regular, but here and there changes, particularly in
TORCHLIGHT DOME. 77

the SW. \ sec. 25, where a dip of 22° was noted, bordered on either 

side by dips of 13°, 15°, and 17°. The structure contours on the 

Greybull sand at intervals of 200 feet above sea level up to 2,800 

feet represent the shape and extent of the dome.

The rocks at the surface in the center of the Torchlight dome 

belong to the upper part of the Frontier formation, which in this 

locality is a little more than 550 feet thick. A prominent sandstone 

of this formation encircles the central part of the dome in a line of 

cliffs and has been given the name Torchlight sand. It was first 

described by Washburne 1 as the "B" sand, and later named the 

Torchlight sand by F. F. Hintze, jr.,2 because of its prominent exposure on this dome. It is not known to contain oil or gas at any 

place in this general region. A thicker and more prominent sandstone, the Peay, in the lower part of the Frontier formation, is not 

exposed in this dome but is well shown along Big Horn River near 

Greybull. Although it contains gas and some oil in the Lamb anticline it is of no importance in the Torchlight dome. Directly underlying the Frontier formation is the Mowry shale, a hard platy shale 

about 160 feet thick in which numerous fish scales occur and which 

contains two sands Kimball and Octh Louie that yield all of the 

oil obtained in this dome. The entire formation, according to H. T. 

Lamb, manager of the Greybull Oil Co., yields some oil. Under the 

Mowry shale is the Thermopolis shale, about 700 feet thick, mainly 

of shale but including a persistent sandstone the Muddy sand, which 

contains a little gas in some wells about 300 feet above its base.

Directly beneath the Thermopolis shale is the Cleverly formation, 

about 125 feet thick, the top sandstone of which is about 20 feet 

thick and is known as the Greybull sand. This bed of sand yields 

all the oil and gas in the Greybull field. Although the oil and gas in 

the Torchlight dome are found in higher beds, it seems advisable to describe the underlying rocks down to and including the Greybull sand, 

because the structure contours are drawn on this sand. The rocks 

below the Cloverly formation are fully described in the first part of 

this report.

Logs of two wells in the Torchlight dome, Jackson No. 7 (No. 34, 

PI. IX) and Kimball No. 2 (No. 11, PI. IX), are given below in order 

to show the positions of some of the beds beneath the surface. The 

bottom of the Jackson well is probably about the base of the Mowry 

shale. This well was "shot" while the writer was in the field. (See 

PL VIII, A)

i Washburne, C. W., Gas fields of the Bighorn Basin, Wyo.: U. S. Geol. Survey Bull. 340, p 350,1908. 

* Hintze, F. F., jr., The Basin and Greybull oil and gas field, Bighorn County, Wyo.: Wyoming Geol. 

Survey Bull. 10, p. 23,1914.
78 ANTICLINES IN SOUTHERN PAET OF BIG HORN BASIN, WYO.

Log of Jackson No. 7 well (No. 34, PI IX), in the SE. J NW. J sec, 24, T. 51 N.,

R. 93 W.

Feet. 

Top of Peay sand; contains water................................ 220

Top of Kimball sand; oil bearing.................................. 438

Top of Octh Louie sand; oil bearing.............................. 485

Bottom of hole................................................... 538

Log of Kimball No. 2 well (No. 11, PL IX), in lot 14, sec. 19, T. 51 N., R. 92 W.

Feet. .

Top of Torchlight sand......................................... 5±

Base of Torchlight sand ........................................ 80

Top of Peay sand.............................................. 358

Base of Peay sand............................................ 458

Top of Kimball sand; oil bearing............................... 560

Base of Kimball sand.....;.................................... 580

Bottom of hole................................................ 588

The Octh Louie sand was not .penetrated by the drill in this well.

DEVELOPMENT.

The first well (No. 1, PI. IX) in the Torchlight dome was drilled in 

1905. It penetrated to a depth of 106 feet and encountered, a little 

gas. Soon a second well (No. 2) 222 feet deep was drilled near the 

first and penetrated the Peay sand, in which gas, water, and a little 

oil were found. No development work was done from 1905 to 1913, 

at which tune Jackson No. 1 (No. 6, PI. IX) was drilled to a depth of 

410 feet, reaching the base of the Kimball sand and proving that 

this sand is oil bearing. This' discovery encouraged further prospecting, and from 1913 to October 1, 1915, 37 wells were drilled, the 

Greybull Oil Co. keeping two strings of tools in use continually. 

Most of the drilling has been done by this company on the Jackson 

and Kimball claims, the former including 160 acres in the E. £ W. £ 

sec. 24, T. 51 N., R. 93 W., and the latter including an equal area in the 

west range of lots (Nos. 7, 8,13, and 14) in sec. 19, T. 51 N., R. 92 W. 

The Valentine interests drilled five additional wells (Nos. 53-57) 

along the east line of the SE. | sec. 24, from October 16, 1915, to 

January 5, 1916, all of which encountered oil. A common type of 

portable drilling rig in use on the Torchlight dome, as well as other 

parts of the Big Horn Basin, is shown in Plate VIII, B.

The daily production of oil from the Torchlight dome in October, 

1915, was believed to be between 800 and 1,000 barrels, but by 

October, 1916, it had greatly declined and was reported to be about 

200 barrels a day. It is transported through a 4-inch pipe line to 

the refinery at Greybull. The gas from the Torchlight dome is used 

only at the camp near the center of sec. 24, T. 51 N., R. 93 W.

The following table furnishes information regarding the wells 

drilled in Torchlight dome up to October, 1915:
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE Vll(

A. OIL THROWN INTO AIR WHEN WELL WAS "SHOT" ON TORCHLIGHT DOME.

B. PORTABLE DRILLING RIG ON TORCHLIGHT DOME.
U. S. GEOLOGICAL SURVEY 

R. 93 W.

BULLETIN 656 PLATE IX 

R. 92 W.

Structure contours 

(lines of equal altitude) on top o 

Greybull sand. 

Numbers show 

distance above or below 

sea level. Contour interval, ZOO feet

ICRAVEDAND PRINTED BY THE U.S-GEOLOGICAL SURVEY

STRUCTURE CONTOUR MAP OF LAMB ANTICLINE AND TORCHLIGHT DOME (Nos. 5 AND 6,

RESPECTIVELY, ON PLATE I) AND STRATIGRAPHIC SECTION

The outcrops of sands are mapped as sandstones

By Charles T. Lupton

Scale
Wells of Torchlight dome, Wyo.

No. on 

map 

(PI. LX).

1 

2

3 

4 

5 

6 

7 

8 

9 

10 

11 

12

13 

14

27 

30

31 

32 

33 

34 

35 

36 

37 

38 

39 

40 

41 

42 

43 

44 

45 

46 

47 

48 

49 

50 

51 

52 

53

Name.

Torchlight No. 1. .........

Torchlight No. 2. .........

Jackson No 1

JCimball No. 1. ...,,.

Tillard... .................

(?)........................

KimballNo. 12............

KimballNo. 10............

KimballNo.9. ............

KimballNo. 8.. ...........

KimballNo. 5. ............

KimballNo. 6.............

KimballNo. 7.............

KimballNo. 13............

Owner.

Torchlight Drilling & Mining Association.

.....do.....................

GreybulIOilCo...........

Cleveland - Wyoming Oil 

Co.

CJeveland - Wyoming Oil 

Co. 

.....do.....................

.....do.....................

.....do.....................

.....do... ..................

.....do.....................

.....do.....................

.....do.....................

m............. ...........

GreybullOilCo...........

.....do.....................

.....do.....................

.....do...........:.........

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

Result."

Water, gas, and a little oil 

from Peay sand.

Oil........................

Oil........................

Water.....................

on........................

.....do.....................

.....do.....................

.....do.....................

.....do...:.........:.......

Oil reported in Torchlight 

sand. 

Oil........................

.....do.....................

(?)........................

Oil........................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

(?)........................

Oil........................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do.....................

.....do....:................

.....do.....................

.....do.....................

.....do.....................

Depth to Kimballsand.

Feet. 

Not reached.

Not reached.

380 

380 

615 

. 390 

800± 

435 

450

(") 

560 

575±

1,058 

Not reached.

405 

400±

Not reached. 

475 

455 

428 

404 

432 

425 

440± 

450± 

Not reached. 

490± 

480± 

475± 

468 

455 

458 

465 

482 

500 

530± 

450± 

560± 

430±

19

19

Ap

Au

M

Au

Se

Se

19

A

O

D

M

Ju

Ju

D

Fe

Fe

Ju

A

Se

A

Ju

D

Ja

Fe

Se

...

...

...

Results given in this column pertain only to Kimball sand. 
80 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

The following analysis, made in the laboratory of the Bureau of 

Mines, of oil from Kimball No. 3 well (No. 9, PL IX) in lot 13, sec. 19, 

T. 51 N., R. 92 W., is believed to be typical of all oil derived from the 

Torchlight dome:

Analysis of oil from the Kimball No. 3 well (No. 9, PL IX), lot 13, sec. 19, T. 51 N.,

R. 92 W.

Began to boil at 34° C.

Gasoline: Percent. 

To 50° C.................................................... 2i

50° to 75°................................................... 4$

75° to 100°.......................................I...'....... 6

100° to 125°.................................;............... 10

125° to 150°................................................. 7$

30$

Kerosene:

150°to 175°................................................. 6

175° to 200°................................................. 5$

200° to 225°................................................. 5J

225° to 250°................................................. 6

250° to 275°............................'..................... 5£

275° to 300°................................................. 9$

38 

Residuum....................................................... 31$

Specific gravities at 60° F.:

Crude oil (49.98° Baum6).................................. 0.7955

Gasoline (64.00° Baume")..----.-.-...-. . ^................. . 7216

Kerosene (42.80° Baume")................................. .8102

Residuum (36.20° Baume").......... ......... ............. .8425

CONCLUSIONS.

The limits of the productive area of the Torchlight dome are accurately known only in one small area along the northeast side and two 

or three small areas along the southwest side. Drilling has been carried on for the most part in proved territory. Owing to the withdrawal of the public land by the Government only a few claims 

(Jackson, Kimball, and Minor) are open for drilling and it is doubtful 

if the field will be definitely outlined until a suitable leasing law 

affords an opportunity to continue drilling to the south, southeast, 

east, northwest, and west. Conditions in the Greybull field and in the 

Lamb anticline suggest that the productive territory probably extends 

farther down the slope on the southwest and west than on the east and 

northwest. It therefore seems'probable that the line separating the 

productive from the nonproductive oil land follows approximately 

the 2,400-foot contour line along the southwest flank. The discovery 

of dry holes (wells 15 and 25) along the south flank of the Lamb anticline and one (No. 28) on the north flank of the Torchlight dome shows
DRY DOME. 81

that the oil-producing area is not everywhere bounded by the 2,400- 

foot contour, because these dry holes are within that contour, hence 

it seems reasonable to assume that possibly near the center of sec. 30 

the line swings north, connecting the 2,400 and 2,600 foot contours, 

and that from that point, near the intersection of the crest line of the 

Torchlight dome with the 2,600-foot contour, it probably keeps 

slightly inside the 2,600-foot contour to the northwest end of the 

dome, where it connects again with the 2,400-foot contour, probably 

near the south quarter corner of sec. 14, T. 51 N., R. 93 W.

DRY DOME.

By CHARLES T. LUPTON. 

GENEEAL FEATURES.

The dry dome (No. 8, PI. I), so named because it is probably barren 

of oil and gas, is a small bulge in the rocks about 5 miles southeast of 

Torchlight dome and 8 miles southeast of Basin, on the Chicago, Burlington & Quincy Railroad. It may be easily reached from Basin by 

a good road from which a secondary road leads for 2 miles to and 

across the dome near its center.

The dome represented in figure 7 lies mainly in sees. 34 and 35, T. 

51 N., R. 92 W., and sees. 1-3, T. 50 N., R. 92 W. The surface near by 

is gently rolling for the most part, with a shallow stream course extending southeast along the east flank. The water supply in and adjacent 

to the dome is exceedingly scanty. There are no springs or perennial 

streams, and water must be obtained either from Big Horn River or 

No Wood Creek or from reservoirs adjacent to stream courses in which 

flood waters have been ponded.

A well -drilled in the NE. i NW. £ sec. 2, T. 50 N., R. 92 W., obtained water in three sands.

STRUCTURE.

The Dry dome is a nearly symmetrical bulge in the rocks, trending 

northwest and southeast, with its broad end facing the northwest. 

The upfold here is slight, not exceeding 500 feet, and is shown by 

the structure contours drawn on the Greybull sand. The dips on 

the southwest side range from nearly flat at 'the crest line to 10° in 

the center of sec. 3, T. 50 N., R. 92* W., a mile to the southwest. 

The maximum dip on the north is 9° in the NE. | sec. 35, T. 51 N., 

R. 92 W., about half a mile from the axis. The dips at the southeast and northwest ends are less than those on the sides.

The surface rocks to a depth of about 300 feet below the surface 

at the top of the dome belong to the dark-gray Cody shale, which 

has a thickness of about 3,200 feet in this locality. Directly below

£6133° Bull. 656 17 6.
82 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

the Cody shale is the Frontier formation, 500 to 600 feet thick, 

which contains two principal sands, the Torchlight and Peay, the 

latter being the only one recognized by the drillers in the well log 

below. Beneath the Frontier is the Mowry shale, about 160 feet 

thick, which contains two sands, the Kimball and Octh Louie, 

which carry the greater part of the oil in Torchlight dome. Beneath 

the Mowry is the Thermopolis shale, about 700 fee't thick, which is

Structure contours (lines of equal altitude) on top of 

G.reybull sand. Numbers show altitude above sea level. 

Contour interval, 200 feet

FIGTJBE 7. Structure-contour map of Dry dome (No. 8, PI. I). The outcrops of sands are mapped as

sandstone.

characterized by a persistent sandstone, the Muddy sand, that lies 

about 300 feet above its base. This shale is dark gray and forms 

an excellent impervious cap to the sandstone bed lying directly 

beneath. Below the Thermopolis shale is the Cloverly formation, 

the top sandstone of which (the Greybull sand) carries oil and gas 

in the Greybull field. The different sands recognized by the drillers, 

as indicated by the log given below, carry water but no trace of oil 

or gas.
MERCER ANTICLINE. 83

Log of dry Jiole in the NE. \ NW. £ sec. 2, T. 50 N., R. 92 W.

Feet. 

Top of Peay sand (water)..................................... 735

Top of Muddy sand (water)................................... 1,475

Top of Greybull sand (water).................................. 1,800

This well was drilled in the early part of 1914 by the Greybull Oil 

Co., of Greybull, Wyo. The elevation of the mouth of the well 

above sea level is 4,240 feet.

CONCLUSIONS.

As the dome has been tested by a well at a point within onefourth mile of the crest line," it seems doubtful if further drilling 

would yield better results. Hence the writer advises against the 

further expenditure of money to make a more thorough test.

MERCER ANTICLINE.

By CHARLES T. LUPTON.

GENERAL FEATURES.

The Mercer anticline (No. 7, PL I) is not at all promising as a 

reservoir of oil and gas, as all the oil sands known in the Big Horn 

Basin are exposed on its flanks. It is 16 to 18 miles nearly due 

east of Basin, 8 to 10 miles northwest of Hyattville, and about the 

same distance northeast of Bonanza. It is included in sees. 28-30, 

32, and 33, T. 51 N., R. 90 W., and sees. 3-5, 8-10, T. 50 N., 

R. 90 W. Manderson, a town of about 200 inhabitants, on the 

Chicago, Burlington & Quincy Railroad, is the nearest railroad point. 

From it the anticline is easily reached, as a good road leads through 

Bonanza to Hyattville and a secondary road, branching near Hyattville, follows a stream valley to the crest of the anticline.

The surface of the anticline (see fig. 8) consists of a basin-like 

depression bounded by inward-facing walls of sandstone and shale. 

This depression has been formed by the wearing away of the rocks 

by the stream, which crosses the anticline in a southerly direction. 

The surface elevations range from about 4,690 feet above sea level 

at the well in the SE. J SE. J sec. 5, T. 50 N., R. 90 W., to about 

5,150 feet in the east part of sec. 33, T. 51 N., R. 90 W.

The only water supply is derived from small springs and the intermittent stream, which, for the greater part of the year, contains only 

a few water holes. Water is reported to have been found in the well 

drilled in the SE. £ SE. J sec. 5, T. 50 N., R. 90 W., on the southwest 

side of the anticline, but its quality is unknown.
84 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

STRUCTURE.

The Mercer anticline is oblong, being about 3 miles long and 1 mile 

wide, measured on the outcrop of the Greybull sandstone. It trends 

northwest and is slightly unsymmetrical, with its steeper limb on the 

mountain or northeast side. At the northwest end the crest swings

R.90 W.

Structure contours (lines of equal altitude) on top of 

Greybull sand. Numbers show altitude above sea 

level. Solid lines indicate position of sand'where 

present.and broken lines former position of sand be.d

Contour interval,' 200 feet 

FIGURE 8. Structure-contour map of Mercer anticline (No. 7, PI. I). The outcrops of sands are

mapped as sandstones.

more nearly west and at the southeast end more nearly south than 

it does through the middle of the upfold. The maximum dip on the 

northeast side is 25° in the northern part of sec. 33, T. 51 N., R. 90 

W., but such steep dips are rare. The steep dips occur in the sandstone beds near the top of the Cloverly formation, the highest sand-
MERGER ANTICLINE. 85

stone of which is known as the Greybull, on which the structure contours 

are drawn. Most of these contours are on that part of the Greybull 

sand which lies below the surface, but those above the 5,000-foot 

contour (which coincides approximately with the outcrop of the top 

of the Cloverly formation) are above the surface on the restored surface of the Greybull sand, which has been eroded away. The pitch 

of the crest at the northwest end of the anticline in sec. 29 is gentle, 

ranging from 3° to 9°, but farther northwest the dips are steeper. 

At the southeast end, in sees. 4 and 9, however, the pitch is steeper 

than it is at the northwest end, ranging from 9° to 15°. On the 

southwest slope the dips are gentle, ranging from nearly flat along 

the crest line of the anticline to 10° or 11° near the outcrop of the 

Greybull sandstone. From this outcrop west and southwest the dips 

gradually flatten.

The structure contours drawn on the Greybull sand show the shape 

and extent of the dome'. With these contours and surface elevations 

the approximate depths of the possible oil sands in any part of the 

dome may be ascertained. (See p. 39.)

The lowest and oldest rocks exposed on the anticline belong to the 

Sundance formation of Jurassic age, about 250 feet thick, which is 

characterized by beds of sandstone and shale and a little fossiliferous 

limestone, all of which have a slightly greenish tint. Overlying the 

Sundance formation are beds of the Morrison formation, about 200 

feet thick, which are strikingly variegated in color with maroon prevailing. Overlying the Morrison is the Cloverly formation, about 

125 feet thick.' At its base in most places is a fine conglomerate or 

coarse-grained sandstone and at its top a sandstone about 20 feet 

thick the Greybull sand. Between the Greybull sand and the conglomerate below are beds of reddish color, mainly shale. Overlying 

the Cloverly is the Thermopolis shale, about 700 feet thick, consisting mainly of dark shale.

The rocks beneath the surface belong to the lower part of the 

Sundance formation, the Chugwater formation, the Embar formation (in which oil and gas may be present), and lower formations.

DEVELOPMENT.

A well that obtained water only was drilled several years ago in 

the southeast corner of the SE. \ SE. I sec. 5, T. 50 N., R. 90 W., 

to a depth, according to Asa Mercer, jr., of Hyattville, of about 900 

feet. In it the drill penetrated part of the dark shale of the lower 

part of the Thermopolis shale; the Cloverly formation, about 125 feet 

thick; the Mprrison shale, about 200 feet thick; the Sundance formation, about 300 feet thick; and went about 200 feet into the Chugwater formation.. Much water was encountered in the lower rocks, 

and the well was abandoned on that account. It is said to have
86 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

risen to within 200 feet of the top of the well and was very alkaline. 

No trace of oil or gas was found, but the well is so far from the crest 

line of the anticline that it can not be regarded as certainly indicating the absence of oil.

The formation in which oil or gas is most likely to be found in this 

locality is the Embar formation, which directly underlies the Chugwater formation ("Red Beds") and which yields oil in the vicinity 

of Lander, Wyo., but in the Big Horn Basin is not known to contain 

oil or gas in commercial quantities. It lies abjout 700 feet below the 

bottom of the well.

CONCLUSIONS.

The most advisable point at which to sink a well with the least 

cost is along the crest line of the anticline in the SE. £ SW. £ sec. 33, 

T. 51 N., R. 90 W., near the same stream on which the well above 

described was drilled. The Embar formation at this point would 

probably be. encountered at a depth of about 1,100 feet. However, 

as the Embar formation is not known to contain oil or gas in commercial quantities in the Big Horn Basin, anyone drilling on this 

anticline with the hope of obtaining oil or gas in the Embar limestone 

does so at the risk of loss of the cost.

The oil, if present, is most likely to be heavy, more nearly like the 

California oil than the light oil obtained in the Torchlight dome at 

Grass Creek or at Greybull. This judgment is based on conditions 

in the Lander field and the existence of the seepage of heavy oil in 

the Red Spring anticline. In both these localities the oil is probably 

derived from the Embar limestone.

MANDERSON ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

TheManderson anticline (No. 10, PI. I) is a northwestward-pitching 

upfold in the eastern part of T. 50 N., Rs. 92 and 93 W., and T. 49 

N., Rs. 91 and 92 W. (See PI. XI, p. 98.) Although two wells have 

been drilled and a third one is being drilled in this anticline, it has 

not beeji adequately tested for oil and gas, as not one of the wells 

penetrates the possible oil and gas bearing sands. The anticline is 

about 12 miles long, and whereas on its southwest limb the rocks dip 

gradually southwestward into the deeper parts of the Big Horn 

Basin, its northeast limb ranges from one-fourth of a mile to 1 1 miles 

in width.

The anticline is easily accessible. The nearest railroad point, Mandersori, a small village near the mouth of No Wood Creek, on the 

Chicago, Burlington & Quincy Railroad, is not more than 5 miles
ANTICLINE. §Y

from the crest of the anticline, which is reached by a good road that 

runs parallel with the creek. Secondary roads and trails and the 

gently undulating surface of the country make it possible to reach 

with ease every part of the anticline.

The principal surface feature in the vicinity of this anticline is the 

valley of No Wood Creek, which is cut about 200 feet below the general level of the upland surface. South of that valley are rolling hills 

of dark-gray shale, with here and there conspicuous sandstone hogbacks. In places badlands occur along intermittent streams. North 

of No Wood Creek for several miles the surface is comparatively 

smooth, being in part a gravel-covered terrace. Adjacent to Big 

Horn River bluffs of sandstone and shale are conspicuous.

The main water supply of this locality comes from Big Horn 

River and No Wood Creek. Both streams are perennial and carry 

a large volume of water throughout the year. Springs are not known 

at any place along the anticline, and water for drilling and domestic 

purposes must be taken from the streams, unless it is obtained from 

wells that pass through the sandstones of the Frontier formation, 

which yields water in most places where they have been tested along 

the east side of the Big.- Horn Basin. The two wells drilled, however, are not deep enough to reach the Frontier formation.

STRUCTURE.

The Manderson is an unsymmetrical anticline which pitches 

from southeast to northwest. Near the southeastern end of the 

crest, however, there is a terrace-like structure where the pitch is 

less than it is either to the north or south. Locally the beds dip 

more steeply on the northeast limb than on the southwest limb of 

the anticline. Adjacent to the crest line the dips are comparatively 

slight, being not more than 10° at any place, but farther away they 

increase for half a mile or more to a maximum of 33° near the northeast corner of sec. 1, T. 49 N., R. 92 W., and then flatten abruptly 

near the axis of the syncline. On the southwest limb of the anticline the dips gradually increase from zero at the crest to 28° at a 

distance of about 1 mile and then gradually decrease to the southwest. The highest dips, as indicated by the nearness of the structure contours, occur mainly in the eastern part of T. 49 N., R. 92 W., 

and the western part of T. 49 N., R. 91 W.

The structure contours and the structure section (see PI. XI) 

show the extent and shape of the anticline. The contours are drawn 

on the top of the Greybull sand, in which the oil and gas occur in 

the Greybull field. The surface elevations range from about 3,940 

feet above sea level on No Wood Creek, near Jordan's mill, in the 

NW. i sec. 34, T. 50 N., R. 92 W., to about 4,570 feet near the center 

of sec. 16, T. 49 N., R. 91 W. From these elevations and from the
88 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

Greybull sand contours the approximate depth to the possible oil 

and gas sands at any place on the anticline may be determined. 

(See pp. 39-41.)

The surface rocks along the anticline belong for the most part to 

the Mesaverde formation and the Cody shale. Near the northwest 

end bed? of younger formations are present, but it is probable that 

this part of the anticline is of little importance, as the depth to the 

sands which may carry oil and gas is so great as to make them almost 

inaccessible. For a mile or more along the crest northwest of No 

Wood Creek the Mesaverde formation is concealed beneath the 

alluvium on the flood plain and the gravel on the terraces, but farther northwest it shows at the surface. The Mesaverde formation Q .

is about 1,200 feet thick and consists mainly of sandstone interbedded with shale, sandy shale, and a little coal. Directly underlying it the Cody shale, about 3,000 feet thick and dark gray in 

color, forms an excellent impervious cap for the underlying sands 

of the Frontier formation. No persistent sandstone beds of any 

importance are found in the Cody shale except possibly two or 

three small ones near the top and one thin but persistent bed near 

the base. Owing to the thickness of the Cody shale, any well 

located near the outcrop of its top must penetrate 3,000 feet of 

shale before reaching any sand that may contain oil and gas. 

Directly underlying the Cody shale is the Frontier formation, 

about 500 feet thick, which consists mainly of sandstone with beds 

of sandy shale and shale interbedded. The uppermost bed that 

needs to be considered is the Torchlight sand, which apparently 

carries little oil in the eastern part of the Big Horn Basin. In 

the lower part of the formation there is a thicker and more conspicuous sandstone known as the Peay sand, which in places carries a little oil and gas. Like the Torchlight sand, however, it 

carries no oil or gas in the eastern part of the Big Horn Basin, 

except in the Lamb anticline, where it has furnished all the gas derived from that field. Under the Frontier formation is the Mowry 

shale, about 175 feet thick, which includes two possible oil sands, 

the Kimball above and the Octh Louie below, which in the Torchlight dome carry high-grade oil. Beneath the Mowry shale is the 

Thermopolis shale, about 700 feet thick, darker than the Cody shale 

and containing about 300 feet above its base a very persistent bed 

of sandstone known as the Muddy sand, which, however, is not 

known to carry oil or gas in commercial quantities, except in the 

Oregon Basin. (Seep. 181.) Directly underlying the Thermopolis 

shale is the Cloverly formation, a generally sandy formation 125 feet 

thick. The top sandstone of this formation, on which the structure 

contours are drawn (see PI. XI), is known as the Greybull sand, as 

it is the sand that contains the oil and gas of the Greybull field. The
MANDERSON ANTICLINE. 89

Cleverly formation contains, in addition to the Greybull sand, which 

is about 20 feet thick, a variegated shale and a lower bed which 

consists, for the most part, of coarse sand but in places is a mediumgrained conglomerate. As any oil or gas that may occur in this 

anticline probably will be found in the Greybull sand or above it, 

a description of lower formations seems unnecessary.

DEVELOPMENT.

Two wells have been drilled on the Manderson anticline, but 

neither of them has penetrated the Frontier formation. One well 

(No. 1, PI. XI) near the center of sec. 1, T. 49 N., R. 92 W., was drilled 

during the fall of 1914 by C. E. Stubbs and others to a depth of about 

800 feet. It is well located to test the anticline, but was not drilled 

deep enough to reach the top sand of the. Frontier formation. The 

elevation of its mouth is about 4,100 feet above sea level. Another 

well (No. 2, PI. XI), in the SE. | sec. 6, is too near the trough of the 

syncline to show whether or not oil or gas is present in the anticline. 

No information is at hand regarding this well except that its mouth 

is about 4,170 feet above sea level. Both the wells are dry holes, 

as neither was drilled deep enough to test fully this part of the 

Manderson anticline. It is reported about December 1, 1916, that 

' in a well being drilled along No Wood Creek near Jordan's mill, and 

near the crest of the Manderson anticline, neither oil nor gas had 

been encountered by the drill.

CONCLUSIONS.

It seems to the writer that the best place to begin drilling is on 

or near the crest line of the anticline south of No Wood Creek, 

because the sands of the Frontier formation are nearer the surface 

here than they are at any other point on the anticline, and that 

the wells should be deep enough to penetrate the Peay sand of that 

formation. The writer recommends locations near the crest line of 

the anticline in sees. 8 and 17, T. 49 N., R. 91 W., because the beds 

here seem to lie on a structural terrace, and this is generally considered favorable for the accumulation of oil and gas. Northwest of 

No Wood Creek the depth of the oil sands is great, and as the anticline pitches steeply, it is believed that this locality is a poor place 

to drill.

Although this anticline seems to plunge throughout its entire 

length, this fact does not preclude it from serving as a reservoir for 

oil and gas, for a differential cementation of the sands of the Frontier 

formation, Mowry shale, and Cleverly formation may make .parts 

of these beds suitable reservoirs.
90 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

PAINTROCK ANTICLINE.1

By CHARLES T. LUTTON. 

GENERAL FEATURES.

The Paintrock anticline (No. 9, PI. I) trends northwest through 

T. 49 N., Rs. 90 and 91 W., and T. 50 N., R. 91 W., about 12 miles 

east of Big Horn River and parallel to and a short distance east of 

No Wood Creek. (See PL XI, p. 98.) It is about 2 miles east of 

Bonanza and by road 15 miles east of Manderson, on the Chicago, 

Burlington & Quincy Railroad. The anticline has been fairly well 

tested for oil and gas along Paintrock Creek near its southern end 

but with negative results. One of the wells drilled to a depth 

of about 1,900 feet found a strong flow of water, and another, not 

so deep, failed to yield oil, gas, or water in appreciable quantities.

The anticline is most easily accessible from Manderson over a 

good road which extends along the valley of No Wood Creek and 

connects with a similar road extending up Paintrock Creek. Second-class roads and trails and the comparatively smooth surface of 

the country make the entire anticline easy to examine.

Like many of the upfolds in the Big Horn Basin the Paintrock 

anticline is represented at the surface for the most part by a depression surrounded by parallel walls and ridges formed by beds of 

outward-dipping sandstone, with intervening valleys formed in soft 

shale. In many places adjacent to the streams the soft shale has 

been cut into badlands which are difficult to cross. The elevation 

of the surface ranges from about 4,075 feet above sea level in the 

NE. i sec. 4, T. 49 N., R. 91 W., to about 4,670 feet in the N. £ sec. 

33, T. 49 N., R. 90 W.

The water supply is from the perennial streams, No Wood and 

Paintrock creeks, and from several that are intermittent. A small 

spring rises near the northern end of the anticline in the NE. £ sec. 

27, T. 50 N., R. 91 W., just north of the Hyattville-Basin road; and 

a few others, very alkaline in character, occur in different parts of 

the anticline. The strong flows of water from several sands in one 

well (Catherine No. 2, No. 11, PI. XI), which was drilled fx>r oil in 

the SW. I sec. 20, T. 49 N., R. 90 W., compelled the drillers to case 

the well in five places. The strongest flow and probably the best 

water is from near the bottom of the hole. This well flows about 

100 gallons a minute. Little water was found in well No. 10 (Catherine No. 1) in the NW. £ sec. 18 of the same township.

1 See footnote, p. 94.
PAINTROCK ANTICLINE. 91 

STRUCTURE.

The Paintrock anticline is an unsymmetrical upfold about 15 

miles long and 4 miles wide. Its narrow steep slope is on the east 

or mountain side and its broad gentle slope on the west or basin 

side. In the vicinity of the crest the dips are comparatively slight, 

but they increase gradually eastward within about half a mile to 

an average of 40° or 45°. A maximum of 60°, however, was locally 

noted on a sandy bed in the Mowry shale in the SE. £ sec. 36, T. 50 

N., R. 91 W. Beyond this the dips become gradually less to the 

axis of the adjacent syncline, which lies from one-third mile to 1$ 

miles to the east. The southwest limb of the anticline is much 

broader than the northeast, ranging from less than one-half mile in 

the southern part of sec. 33, T. 49 N., R. 90 W., to as much as 4 

miles in the southern part of T. 50 N., R. 91 W., and the northern 

part of T. 49 N., R. 91 W. The beds attain a maximum local dip 

of 23° about a mile west of the crest line of the anticline, in the 

W. £ sec. 2, T. 49 N., R. 91 W., averaging, however, about 15°. 

West of this zone of maximum tilting the dip gradually decreases 

to the axis of the syncline. The strata at the south end of the 

anticline dip rather steeply to the south, but at the north end they 

flatten and merge with the broad flat-lying area east of the Torchlight dome and the Lamb anticline.

The structure contours on the Greybull sand show that the highest 

point along the crest line is 2 miles north of Pamtrock Creek.

Few faults are known in the anticline. One of slight throw, with 

downthrow on the west, is between the southeast end and No Wood 

Creek. Another fault is on the crest at the north end of the outcrop of the Frontier formation in the NE. J sec. 27, T. 50 N., R. 

91 W. The downthrow at this place is slight and on the west side.

The lowest rocks exposed in the Pamtrock anticline belong to the 

Sundance formation. This formation outcrops on both sides of 

Paintrock Creek in the western part of T. 49 N., R. 90 W., and consists of 200 to 300 feet of light-green sandstone with a little shale 

and thin beds of fossiliferous limestone. Overlying the Sundance are 

the Morrison and Cleverly formations, Thermopolis and Mowry shales, 

Frontier formation, and Cody shale. The Morrison consists of about 

200 feet of variegated sandstone and shale, the latter predominating. It is overlain by the Cloverly formation of about 125 feet of 

san'dstone and shale, the lower part of which is usually conglomeratic, 

the middle part very clayey and variegated, and the upper part 

sandy. This upper sandy part is the Greybull sand, which carries 

oil and gas in the Greybull field. The Cloverly is overlain by the 

Therjnopolis shale, which is about 700 feet thick and contains in its 

middle part about 20 feet of soft sandstone the Muddy sand. The
92 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

Thermopolis shale, Mowry shale, Frontier formation, and Cody shale, 

which are exposed around this anticline, are described on pages 19-25.

Underlying the Sundance and other formations exposed in the 

anticline is about 900 feet of the Chugwater formation ("Red Beds"), 

which consists principally of sandstone and sandy shale with a thick 

bed of gypsum near the top. Underlying the Chugwater is the 

Embar formation, consisting principally of limestone, but containing in places a thick bed of gypsum near its top. Although this 

formation is known to carry oil in the vicinity of Lander, Wyo., 

no evidence is at hand to show that it carries oil in the Big Horn 

Basin. Below the Embar is the Tensleep sandstone, and underlying that is the Amsden formation, consisting mainly of maroon to 

red sandstone and sandy shale. Underlying the Amsden is the 

Madison limestone, consisting entirely of massive to medium-bedded 

limestone. Neither of the wells drilled on the west limb of the 

Paintrock anticline is believed to have reached this limestone, but 

the Catherine No. 2 well ,(No. 11, PI. XI), which encountered much 

water near the bottom of the hole, is believed to have obtained it 

from the Tensleep sandstone, which carries much water in the region.

Structure contours drawn on the Greybull sand supplemented by 

the structure section (see PI. XI) show the shape and extent of the 

anticline. With those and surface elevations given, the depths of 

wells penetrating the Greybull sand or any other sand whose position with relation to the Greybull is known may be determined 

with ease. (See p. 39.)

DEVELOPMENT.

Three wells the Graves, the Catherine No. 1, and the Catherine 

No. 2 (Nos. 12, 10, and 11, respectively, PI. XI) have been drilled 

on the west flank of the Paintrock anticline. None of them found oil 

or gas in commercial quantities, but the Catherine No. 2 struck 

water at several horizons, the lowest flow being artesian. The Graves 

well also tapped a little artesian water.

The Graves well, near the east quarter corner of sec. 14, T. 49 N., 

R. 91 W., was drilled about 1888 by R. J. Coles, of York, Nebr., to a 

depth of about 1,200 feet (elevation of the mouth, about 4,090 feet 

above sea level). No oil or gas was reported, but a small quantity 

of water flows from the well. The rig used was of the standard type 

and was hauled by wagon from Casper, Wyo., an arduous task at the 

time.

Catherine No. 1 well (No. 10), in the NW. | sec. 18, T. 49 N., 

R. 90 W., was drilled to a depth of about 1,000 feet by L. E. Croll 

and others in May, June, and July, 1914. A little water and a trace 

of oil were encountered. The altitude of the mouth Is about 4,300 

feet. According to report the well was abandoned because the tools
BONANZA ANTICLINE. 93

were lost in the hole, but it is estimated that the drill penetrated 

300 or 400 feet into the Chugwater formation ("Red Beds").

Catherine No. 2 (No. 11) was drilled by L. E. Groll and others to 

a deoth of about 1,900 feet. Drilling was begun in August, 1914, 

and ceased in November of the same year. According to report, the 

well contains no trace of oil, but is believed to have encountered 

water hi four or five sands at least, as it contains five casings. Water 

flows from the well continuously at the rate of about 100 gallons 

per minute and is used near by for irrigation. It is slightly warm and 

contains iron and sulphur in solution. It is believed that this water 

is derived from the Tensleep sandstone, which is an important water 

bearer of the region. The well is in the SE. I SW. J sec. 20, T. 49 N., 

R. 90 W., and the altitude of its mouth is about 4,290 feet.

CONCLUSIONS.

As strata as low as the Sundance formation are exposed at the 

surface in the valley of Paintrock Creek, it seems safe to say that oil 

will probably not be found in any of the rocks in or adjacent to the 

anticline above that formation. The next lower bed in which oil and 

gas may possibly occur is the Embar limestone-, which undoubtedly 

was pentrated in Catherine No. 2 well (No. 11, PL XI). As this well, 

which is near the crest and not far from the highest part of the anticline, did not obtain oil in any of the sands down to and including the 

Tensleep sandstone, it seems reasonable to believe that the chance 

for obtaining oil or gas in deeper beds is very doubtful. As the Embar 

is believed to be of little or no importance as an oil or gas reservoir 

in this part of the Big Horn Basin, and as direct connection with the 

Ulterior of the basin is cut off by the Bonanza anticline, the wisdom of 

expending more money in drilling for oil and gas is doubtful.

BONANZA ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Bonanza anticline (No. 11, PI. I) is situated west of No Wood 

Creek near the mouth of Paintrock Creek, mainly in T. 49 N., R. 

91 W. It is about 12 miles southeast of Manderson, a town on the 

Chicago, Burlington & Quincy Railroad, and a short distance west of 

Bonanza post office. (See PI. XI, p. 98.) Several wells have been 

drilled on this anticline, but none of them has produced oil or gas 

in commercial quantities. A seep near the highest part of the anticline, discovered about 30 years ago, has yielded some oil which was 

used for lighting by the settlers at times when the refined product 

was scarce,
94 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

This anticline is most easily accessible from the railroad at Manderson by means of a good road which follows in general the course of 

No Wood Creek. From Bonanza a second-class road leads to the 

crest of the anticline about a mile distant. Another second-class road 

crosses the north end of the anticline. The southeast end can be 

most easily visited by following the main road along No Wood 

Creek as far as the mouth of Cottonwood Creek, where a secondclass road leads northwest to the southeast end of the anticline, 

about 2 miles distant. Many parts of the anticline, however, are 

accessible only on foot or horseback.

A troughlike depression surrounded by an inward-facing wall of 

shale, in places 300 feet in height, coincides with the central part of 

this anticline, and a series of low hogback ridges partly encircle the 

depression. On the northeast side the shale wall is cut by several 

canyons, which form easy routes of access into the central part of 

the upfold. Badlands are common in the region near the heads of 

streams. The altitude of the surface varies from 4,160 feet above 

sea level in the NW. | NW. J sec. 23, T. 49 N., R. 91 W., to about 

4,650 feet near the center of sec. 36 of the same township. From 

these elevations and from the structure contours on the Greybull 

sand (PI. XI) the depth to the different sands may be determined 

approximately.

Water is available from No Wood Creek, which carries a large flow 

the year round. The intermittent streams emptying into No Wood 

Creek carry water in spring, early in summer, and after heavy 

rains, but throughout the greater part of the year they are dry except 

for a few small seeps and water holes.

STRUCTURE.

The Bonanza anticline * is an unsymmetrical northwest-pitching 

upward fold slightly offset on the northwest from the Manderson 

anticline and on the southeast from the Nowood anticline. Like 

many of the upfolds on the east and south rims of the Big Horn 

Basin, Bonanza anticline has steep dips on the mountain side and 

much more gentle dips on the basin side. For this reason the northeast limb is much narrower than the southwest. The dip on the 

east ranges from zero at the crest line to 54° locally, about 500 feet 

east of it,in the NE. J SE. I sec. 36, T. 49 N., R. 91 W., beyond which 

it gradually decreases to zero at the trough of the syncline one-half 

mile distant. Farther northwest the dips on the northeast limb

i Knight held the opinion that the Bonanza anticline extended several miles south of the mouth of Cottonwood Creek and would have this anticline include the Nowood anticline of the present writer's classification, which is separate and distinct from the Bonanza anticline. The term "Nowood anticline" as 

used by Knfght pertains to the Paintrock anticline of the present report. (See Knight, W. C., and Slosson, 

E. E., Bonanza, Cottonwood, and Douglas oil fields: Wyoming Univ. Bull., Petroleum ser., No. 6, pp. 

6-13,1903.)
BONANZA ANTICLINE. 95

fii'st average about 45° for 2 miles, and then decrease gradually. On the 

west limb the beds range in dip from zero at the crest line to a 

maximum of 18° H miles distant in sec. 34, T. 49 N., R. 91 W. 

Farther southwest for a mile or more the beds increase in dip. At 

the southeast and northwest ends of the fold the dips are low. A 

maximum of 12° was noted at the northwest end in the SW. \ sec. 9, 

T. 49 N., R. 91 W. The southern half of this anticline slopes gently 

northwestward, but the part northwest of the oil seep in the SW. J 

sec. 23, T. 49 N., R. 91 W., pitches more sharply.

The lowest rocks exposed on the anticline belong to the upper part 

of the Thermopolis shale. This shale is about 600 feet thick, and 

contains a persistent bed of sandstone the Muddy sand about 250 

feet above its base. This sand is exposed only at the extreme southeast end of the anticline and is not known to carry oil or gas of 

economic importance except in the Oregon Basin (p. 185). Directly 

overlying the Thermopolis shale is the Mowry shale, a dark-gray, 

hard,,platy shale about 175 feet thick, containing one or more beds 

of sandstone, which in the Torchlight dome have been given the names 

Kimball and Octh Louie sands and which contained the greater part 

of the oil produced in that locality. It is from this formation that 

the oil seepage referred to above issues. Overlying the Mowry is 

the Frontier formation, which consists mainly of sandstones with 

thin layers of sandy shale and bentonite. On the east side of the 

basin it includes two prominent sandstones Torchlight and Peay 

and at the south and west sides as many as five or six. It is about 

600 feet thick, and its sandstones carry oil in some parts of the Big 

Horn Basin, as, for example, in the Grass Creek and the Little Buffalo 

basin fields. Directly overlying the Frontier is the Cody shale, the 

highest formation exposed around the Bonanza' anticline. It is 

about 3,000 feet thick and consists mainly of light-gray shale with 

thin beds of fossiliferous sandstone near the top and a nonpersistent 

bed near the base. If a well were drilled at the northwest end of 

this anticline it would penetrate part or all of the formations described.

Beneath the Thermopolis shale, the lowest outcropping formation, 

toes the Cleverly formation, about 125 feet thick. The Cleverly 

consists of a very persistent bed of sandstone known as Greybullsand, 

on which the structure contours shown on Plate XI are drawn, underlain by about 80 feet of shale and by about 25 feet of conglomeratic 

sandstone. Beneath the Cloverly is the Morrison formation, about 

200 feet thick, consisting mainly of variegated sandstone and shale 

and not known to contain any oil or gas bearing sands. Underlying 

the Morrison is theSundance formation, about 250 feet thick, which is 

mainly sandstone with minor amounts of shale and in places a little 

limestone, all slightly grayish. Beneath the Sundance is the Chugwater formation ("Red Beds") about 1,000 feet thick. It consists
96 ANTICLINES IN* SOUTHERN PART OF BIG HORN BASIN, WYO.

mainly of sandstone but includes thin beds of sandy shale and shale 

and a thick bed of gypsum near the top. Directly underlying the 

Chugwater is the Embar formation, consisting of limestone, gypsum, 

and red sandy shale. At Lander, Wyo., the Embar produces a 

heavy oil, but at no place in Big Horn Basin is it known, to be important as a bearer of oil or gas.

The structure contours drawn on the Greybull sand and the 

structure section (PL XI) show the shape and extent of the Bonanza 

anticline.

DEVELOPMENT.

Seven wells (Nos. 3-9, PL XI) have been drilled on and near the 

Bonanza anticline, but none of them has discovered oil or gas in commercial quantities. An oil seep.in sec. 23, T. 49 N., R. 91 W., about 

three-fourths mile southwest of Bonanza post office, known variously 

as "Bonanza oil seep" and the "No Wood oil seep," was discovered 

in the early eighties, and had led to most of the drilling in this as 

well as other anticlines along the east side of the Big Horn Basin.

The first well (No. 3) on the Bonanza anticline, in the NE. J NE. J 

sec. 28, T. 49 N. ; R. 91 W., was drilled about the year 1900 by the 

Hoosier Oil Co., of Goodland, Ind. For financial reasons the drill 

was not sunk to the Frontier formation. The elevation of the mouth 

of the well is about 4,270 feet.

The next drilling on this anticline was in the spring of 1902, when 

well No. 4 (the Whittier well) was drilled in the NW. I NE. \ sec. 27, 

T. 49 N., R. 91 W., by Gardner Bros., of Knox, Pa., for the Kearn Oil 

Co. A little water was obtained in the bottom of the hole but no 

trace of oil or gas. The altitude of the mouth of the well is about 

4,225 feet.

In 1903 the same drillers put down a hole (well No. 5) near the oil 

seep in the NW. f SW. f sec. 23 to a depth of about 800 feet with a 

standard rig. As this hole is within a few hundred feet of the original 

oil seep oil and gas were encountered, and gas continues to issue to the 

surface through the water around the casing. The altitude of the 

mouth of this well is about 4,260 feet. During the same year another 

well (No. 6) was drilled a short distance south of well No. 5 by Charles 

Cole. The depth attained is not known, but the drilling was done, it 

is reported, by horsepower. There is no evidence that any trace of 

oil or gas was found. The elevation of the mouth of this well is about 

4,300 feet above sea level.

In 1914 B. F. Webster and others, of Colorado Springs, Colov 

drilled a hole on the crest line of the anticline in the SE. J NE. J sec. 

26, T. 49 N., R. 91 W. (No. 7) to a depth of about 600 feet. The 

drill probably reached the Cleverly formation for reddish material 

found in the ma^s of sand and shale brought up by the bailer,
NO WOOD ANTICLINE. 97

A standard rig (see PL IV, B, p. 20) was used in drilling. The altitude 

of the well mouth is about 4,380 feet. A well (No. 8) drilled in the 

NE. I NE. I sec. 36 on the north flank of the anticline did not obtain 

oil or gas in commercial quantity. No information was obtained 

regarding the depth of the well, but the altitude of its mouth is about 

4,245 feet. In 1914 a well (No. 9) was drilled near the southeast end 

of the anticline in the NW. J sec. 6, T. 48 N., R. 90 W., but neither 

oil nor gas was obtained. The elevation of the mouth of this well is 

about 4,240 feet above sea level.

CONCLUSIONS.

The wells already drilled on the Bonanza anticline have not yielded 

sufficient oil and gas to encourage further exploration. The fact, 

however, that oil and gas in commercial quantities have not yet been 

discovered should not condemn the anticline, as it is entirely possible 

that some oil may be found at places along the west limb where a 

flattening of the dips has not been thoroughly tested.

Experience has shown that as a general rule wells on the broad, 

gentle limb of an anticline adjacent to the crest line are more likely 

to obtain oil and gas than wells on the narrow steep limb. In this 

district five of the seven wells are on the narrow steep limb, and the 

remaining two wells, although half a mile to a mile from the crest line 

and on the broad gentle flank, were probably not drilled sufficiently 

deep to penetrate the beds from which the oil issues at the seep in 

sec. 23. Hence these wells are not sufficient tests for the southwest 

limb of the anticline.

The writer-therefore suggests that wells drilled on this anticline in 

the future be located on the southwest limb about half a mile from 

the crest line or near the southeast end of the anticline, in the SW. J 

sec. 31, T. 49 N., R. 90 W., or in the NE. J sec. 1, T. 48 N., R. 91 W. 

In the former locality the Greybull sand should be penetrated, and 

in the latter it possibly would be worth while drilling to the Embar 

formation.

NO WOOD ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The No Wood anticline * (No. 14, PI. I) is an unsymmetrical upfold 

lying mainly in the northern part of T. 48 N., Rs. 89 and 90 W., west 

of No Wood Creek. It has been tested for oil or gas by a deep well 

near the mouth of Cottonwood Creek in sec. 5, T. 48 N., R. 90 W. 

Water was reported to have been encountered, but no trace of oil 

and gas was found.

1 See footnote under "Bonanza anticline/' p. 94. 

86133-° Bull. 656 17 7
98 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

This anticline (see PL X, A) is easily accessible from Manderson, a 

small town on the Chicago, Burlington & Quincy Railroad, by means 

of a first-class road which follows the valley of No Wood Creek 

almost its entire length. A daily mail stage runs over this road 

between Manderson and Tensleep, a town about 12 miles southeast of 

the anticline. Any detailed examination of the region embraced in 

the anticline must, however, be made on foot or horseback, as no 

good roads lead to any part of it.

The anticline coincides with a troughlike depression from which 

the rather broad valley of No Wood Creek lying directly to the east 

is separated by several cross valleys. The troughlike depression is 

surrounded by walls of sandstone and shale of differing heights. 

Outside this wall and encircling the greater part of the anticline are 

lower, less conspicuous walls formed of the edges of hard beds that 

dip away from the crest line. Adjacent to stream courses badlands 

are common.

The water supply for the anticline is derived from No Wood Creek, 

a perennial stream that carries a large amount of water throughout 

the year. This can be used at all times for drilling and domestic 

purposes, except possibly when the stream is unusually muddy. The 

intermittent streams which cross the anticline can also be counted 

on to furnish water during the spring and early in summer. No 

springs of importance are known.

STRUCTURE.

The No Wood anticline is an unsymrnetrical upfold about 8 iniles 

long, with its steep slope on the northeast or mountain side-. (See 

PI. XI.) In this respect it is similar to most of the anticlines of the 

Big Horn Basin. The east slope ranges in width from about onethird mile near the northwest end of the anticline to as much as 1$ 

miles near the southeast end. The dips on this limb increase from 

zero at the crest line of the anticline to as much as 80° one-third mile 

to the east, beyond which they decrease as the beds descend into the 

bottom of the syncline. On the southwest limb the dips range from 

zero near the crest line to as much as 39° locally near the middle of 

the upfold and less than one-fourth mile" west of the axis. They 

average about 15°, however. From this place the dips gradually 

decrease southwestward for a mile or more, then increase slightly to 

the edge of the area represented on Plate XI. The dips at the northwest and southeast ends of the anticline are slight. The northwest 

end of No Wood anticline is slightly offset from the Bonanza anticline.

The highest part of the anticline is on No Wood Creek, near the 

mouth of Cottonwood Creek. The structure contours also show a 

minor upfold on the anticline in sees. 29, 30, and b^, T. 48 N., R. 89 W.
U. 8. GEOLOGICAL SURVEY BULLETIN 656 PLATE X

A. SURFACE APPEARANCE OF NO WOOD ANTICLINE WEST OF NO WOOD CREEK, BETWEEN

BONANZA AND TENSLEEP.

Beds dip in opposite directions from crest line.

B. MAHOGANY BUTTE, EAST OF NO WOOD CREEK, IN SOUTHEASTERN PART OF BIG HORN BASIN.
BULLETIN 656 PLATE XI

U. S. GEOLOGICAL SURVEY

Structure contours (lines of equal 

altitude) on top of Greybuil sand. 

Numbers show distance above 

below sea level. Solid ill

. s

N '\'~ "-~ / \ ,-

\ "-* >mr\ /^ \ \ --V~---z

| indicate present position of sand 

below, and broken lines former 

position above present surface 

Contour interval, 200 feet

\ kf \

s<&

r-/~ *&**

Manderson anticline Bonanza antlci.'ne Paintrock anticline

STRUCTURE CONTOUR MAP OF PAINTROCK., MANDERSON, BONANZA, AND NO WOOD ANTICLINES (Nos. 9, 10, 11, AND 14, RESPECTIVELY, ON PLATE i)

AND TWO STRUCTURE SECTIONS

The outcrops of sands are mapped as sandstones

By Charles T. Lupton

The anticlines are numbered 9,10, II, and 

respectively, on Plate 1.
NO WOOD ANTICLINE. 99

A minor separate anticline is developed at the southeast end of the 

No Wood anticline, in sec. 32, T. 48 N., K. 89 W., and in sees. 5 and 8, 

T. 47 N., R. 89 W. This upfold is about 1\ miles long and has a 

narrow east limb and a broad west limb. The Greybull sand (top 

of the Cloverly formation) may serve as a reservoir for oil and gas 

under this upfold.

The lowest rocks exposed at the surface belong to the upper part 

of the Chugwater formation, which consists mainly of red sandstone 

and shale about 1,000 feet thick with a thick bed of gypsum near 

the top. It is of no economic importance as a bearer of oil and gas, 

but in certain localities on the east side of Big Horn Basin it is known 

to carry much water. The Sundance formation, which directly 

overlies the Chugwater formation, is about 250 feet thick. It consists mainly of sandstone with thin layers of shale and in places a 

little fossiliferous limestone, all greenish. Directly overlying the 

Sundance is the Morrison formation, about 250 feet thick, consisting mainly of sandstone and variegated shale but containing no 

beds known to be oil or gas reservoirs. Directly overlying the Morrison is the Cloverly formation, about 125 feet thick. The lower 

part is usually conglomeratic, the middle part is variegated and 

clayey, and the upper part is the 20-foot Greybull sand, on which 

the structure contours on Plate XI are drawn. This sand is not 

oil-bearing in this anticline, as its edge is exposed at the surface, 

and any oil that it may have contained has long ago escaped.

Overlying the Cloverly formation is the Thermopolis shale, 

about 600 feet of dark shale containing a thin sandstone bed, the 

Muddy sand, which occurs near the middle of the formation. This 

sandstone is not known to carry oil or gas in commercial quantities 

at any place in the Big Horn Basin except in the Oregon Basin.

The rocks lying beneath the lowest beds exposed in the anticline 

include the lower part of the Chugwater formation. Directly beneath the Chugwater is-the Embar formation, which in some localities consists of 100 feet or more of limestone and which near Lander, 

Wyo., bears a heavy oil. In places in the Big Horn Basin the Embar 

is largely gypsum, thin beds of limestone, red sandstone, and shale, 

rather than limestone. The formations below the Embar are not 

known to contain oil or gas.

From the structure contours (PI. XI) on the Greybull sand arid 

the surface altitudes, which range from about 4,160 feet on No Wood 

Creek, in the SE. J sec. 32, T. 49 N., R. 90 W., to about 4,900 

feet in the SW. \ sec. 14, T. 48 N., R. 90 W., the probable depths 

to the different sands may be determined. A structure section on 

Plate XI gives additional information regarding the shape of the 

anticline.
100 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

CONCLUSIONS.

There is little prospect, in the writer's opinion, of finding an oil 

or gas pool in the No Wood anticline in any other part of the structure 

than that already tested. Any oil or gas would probably be in the 

Embar limestone, which is comparatively thin and unpromising. 

It is possible, however, that some of the sandstone beds in the Sundance or Chugwater formations may carry oil in small quantities, 

but this is doubtful, for these formations are not known to be oilbearing in this general region. The most favorable location for a 

well on the No Wood anticline is at the mouth of Cottonwood Creek, 

in the N. £ sec. 5, T. 48 N., R. 90 W., as this is the highest place 

structurally on the anticline. This part of the fold is believed to 

have been thoroughly tested. Near the south end of the anticline, 

in sees. 29, 30, and 32, T. 48 N., R. 89 W., as shown by the structure 

contours, there is also another high place in the anticline, and it 

is possible that small quantities of oil or gas may have accumulated 

there. The small gentle anticline at the southwest end of the No 

Wood anticline, in sees. 5 and 8, T. 47 N., R. 89 W., and sec. 32, 

T. 48 N., R. 89 W.; may carry oil and gas in small amounts.

ZEISMAN DOME. 

By CHARLES T. LUFTON. 

GENERAL FEATURES.

The Zeisman dome (No. 12, PL I) is an untested, unsymmetrical 

anticline of domelike form 4 or 5 miles southeast of Hyattville and 

about 20 miles east and slightly south of Manderson, on the Chicago, 

Burlington & Quincy Railroad. It is included mainly within sees. 

22-27 and 35, T. 49 N., R. 89 W.

It can be visited with comparative ease, as a good stage road 

connects Manderson on the railroad with Hyattville, 25 miles to 

the east, and the main road between Hyattville and Tensleep crosses 

the west slope of the dome. From this main road a good road ascends 

the west limb, and another a second-class road follows the south 

and east sides. These roads, together with numerous trails, enable 

one to examine the region in detail.

The surface of the dome is a large, nearly round hill, ranging in 

altitude from about 4,600 feet at the Zeisman ranch to about 5,700 

feet at the stone cairn on the top of the hill about 2 miles to the 

north. The dips on the east and southeast side are much steeper 

than those on the northern and western sides. Deep canyons have 

been cut by streams on the west and south, but on the north and 

east the surface is comparatively smooth. In places near the heads 

of streams badlands are present.
ZEISMAET DOME. 101

The water supply is derived wholly from an intermittent stream 

known as Alkali Fork of Buffalo Creek, 'which drains the greater 

part of the surface of the dome. On the south fork of this stream 

several springs of fairly good flow could furnish sufficient water for 

drilling and camp use in addition to supplying, as at present, the 

adjacent ranches. Reservoirs to catch and hold the flood waters 

could be made with but little difficulty along many of the minor valleys. If drilling were done on the top of the dome, however, it would 

be necessary to haul or pump water from the springs in the valleys 

until water was reached by the drill.

STRUCTURE.

The Zeisman dome (PI. XII), as determined by measurements on 

the outcrop of the Embar formation, is about 2£ miles long and 

1£ miles wide and trends northwest-southeast parallel to the foot 

of the Big Horn Mountains a few miles to the east. It4s unsymmetrical in form, as the northeast limb is much steeper and narrower 

than the west limb. The dips on the northeast side vary from zero 

at the crest line to as much as 35° or 40° one-fourth mile distant, and 

then descend gradually into a shallow syncline about 1$ miles to the 

northeast. The beds on the west limb dip more gently, and vary from 

zero at the crest line of the dome to 16° locally at a point about 1$ 

miles to the west. The average dip on the west limb is about 12°.

A shallow saddle separates this dome from the Brokenback anticline, the north end of which lies within 1£ miles of the highest 

point in the Zeisman dome.

Structure contours on the top of the Madison limestone supplemented by a structure section (PL XII) show the shape and 

extent of the dome. From these contours and from the surface altitudes (p. 39) the approximate depth to the different sands may be 

determined.

The lowest rocks exposed in the dome belong to the Tensleep 

formation, mainly sandstone, which in this locality is about 200 feet 

thick and commonly contains water. Overlying this formation and 

encircling the top of the dome is the Embar formation, about 400 feet 

thick, which in this locality consists of beds of sandstone, limestone, 

shale, and gypsum. In other parts of the Big Horn Basin, however, 

it consists, mainly of a fossiliferous limestone, which contains traces 

of asphaltum, suggesting that it may, where covered, carry oil and gas 

in commercial quantities, as it does in the vicinity of Lander, Wyo. 

Owing to the fact that this formation is exposed around the dome, 

any oil that it may have formerly contained has probably evaporated, and therefore it may not at present contain either oil of gas. 

Overlying the Embar is the Chugwater formation (''Red Beds"),
102 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

which forms the surface rock of a belt a mile or more in width on the 

west, north, and east sides of the dome. It is about 1,000 feet thick, 

and is mainly red sandstone with small amounts of shale and a thick 

bed of gypsum near the top.

The rocks that are buried under the dome belong to the lower part 

of the Tensleep sandstone, the Amsden formation, about 200 feet 

thick, and the Madison limestone, about 800 feet thick, on the top of 

which the structure contours are drawn. The Madison limestone is 

generally dense and massive and affords no opportunity for the collection of oil or gas, but if it should prove to be porous it might serve 

as such a reservoir. Any oil or gas accumulating in the upper part of 

the Madison limestone would have been caught and held, where the 

structure is favorable, under the shale beds in the lower part of the 

Amsden.

CONCLUSIONS.

No drilling has been done on the Zeisman dome, and, so far as the 

writer is aware, there are no oil seeps or gas vents at any point on the 

surface. The only formation believed to be a possible reservoir in 

this dome is the upper part of the Madison limestone, which is securely 

capped by the Amsden formation. This limestone is probably too 

dense to serve as an oil reservoir, but it may contain some gas. The 

Madison has been carefully tested by the drill near Spence on Big 

Horn River, just east of Sheep Mountain, about 35 or 40 miles to the 

northwest, where it contains but small quantities of oil. If drilling 

should be done on the Zeisman dome, the writer recommends a 

location near the top of the dome, probably on the wood road, at 

some point in the SW. J sec. 23, T. 49 N., R. 89 W., where the 

Madison limestone should beiound at a depth of not more than 500 

feet.

BROKENBACK ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

Brokenback anticline (No. 13, PI. I) is an untested, unsymmetrical 

upfold situated on the west flank of Big Horn Mountains between 

Hyattville and Tensleep. (See PI. XII.) It is doubtful if it contains oil and gas, because all of the sands, except the Madison limestone, that possibly may carry oil and gas are exposed on its crest.

This anticline can be visited with comparative ease, as a welltraveled road follows along its southwest flank to Hyattville and 

thence to Manderson and Basin. Near the south end of the anticline 

a fairly well traveled second-class road crosses the upfold and leads 

into the Big Horn Mountains. Other parts of the anticline must 

necessarily be visited on foot or horseback, as the surface is hilly.
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XII

Structure contours (lines of equal altitude) on top of

Madison limestone. Numbers show distance above 

or below sea level. Contour interval, 200 feet

STRUCTURE CONTOUR MAP OF ZEISMAN DOME AND BROKENBACK ANTICLINE (Nos. 12 and 13, RESPECTIVELY, ON PLATE I) AND TWO STRUCTURE SECTIONS

By Charles T. Lupton
BROKENBACK ANTICLINE. 103

This anticline is represented on the surface by a prominent ridge, 

which coincides closely with the crest line of the fold. The southeast 

end is crossed by two main branches of Brokenback Creek, which flow 

in deep ravines. Numerous small intermittent streams here also cut 

ravines, so that the surface near the anticline is exceedingly rough. 

Badlands are common, particularly on the southwest limb, where the 

gypsum and soft shale beds in the upper part of the Chugwater formation form the surface.

The water supply is obtained from the two branches of Brokenback 

Creek, perennial streams heading in the Big Horn Mountains. At 

the north end of the anticline there are several springs on a prominent 

tributary of Alkali Fork of Buffalo Creek; and there are a number 

of others which rise hi a prominent structural valley on the northeast 

side of the anticline and drain into a large reservoir.in sec. 8, T. 48 N., 

R. 88 W. There are also a number of springs along the two forks 

of Brokenback Creek. Reservoirs could be made with comparative 

ease along the intermittent stream courses on the southwest slope 

of the anticline, where water for domestic use and for drilling could 

be stored. The Tensleep sandstone, which outcrops on the crest of 

the anticline, is a prolific water bearer and undoubtedly would furnish 

sufficient water for use in prospecting when penetrated by the drill.

STEUCTURE.

The Brokenback anticline (PL XII) is an unsymmetrical upfold 

about 8 miles long, with its broad limb on the southwest or basinward side. It is characterized by a local elongated dome developed 

at its southeast end. Like most of the upfolds along the east side 

of the Big Horn Basin the northeast limb is narrow, the dips attaining a local maximum of 45° in sec. 1, T. 48 N., R. 89 W., about onefourth mile northeast of the crest line, and beyond this the beds 

gradually dip into the syncline, which lies about one-half mile to the 

northeast. The dips on this limb near the southeast end of the 

anticline are much less, a maximum of about 5° being observed near 

the center of sec. 27, T. 48 N., R. 88 W. The dips on the southwest 

limb are less than those on the opposite limb and attain a maximum 

of 12° in the SW. f sec. 1, T. 48 N., R. 89 W., about one-fourth 

mile from the crest line, southwest of which the dips gradually decrease 

for a mile or more and then increase slightly, to diminish once more 

to zero at the synclinal trough, a few miles southwest near No Wood 

Creek. The structural terrace formed by the change in dip may 

catch and hold any oil or gas migrating up the limb.

At the northwest end of the anticline a shallow saddle separates 

the Brokenback anticline from the Zeisman dome. At the southeast 

end on the anticline the beds dip gently southeastward to a shallow
104 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

trough, then rise to a low dome, from which they descend to a syncline 

separating the upfold from the west slope of the Big Horn Mountains.

The beds are faulted for a mile or more on the northeast side of 

the anticline about half a mile from the crest line. The downthrow, 

about 75 feet, is on the northeast or mountain side, and the fault 

is parallel to the crest line of the anticline, thus constituting a strike 

fault. No other faults are known.

The structure contours drawn on the top of the Madison limestone 

and the structure section (PI. XII) show the shape and extent of the 

Brokenback anticline. From these contours and from the surface 

elevations, which vary from about 4,500 feet near Zeisman's reservoir in the northern part of sec. 4, T. 48 N., R. 89 W., to about 5,400 

feet in the NE. | sec. 2 of the same township, the approximate depths 

to the different sands may be determined.

The lowest rocks exposed in the anticline belong to the Tensleep 

formation, about 200 feet thick, mainly of gray to buff, medium to 

coarse grained sandstone, which in this locality generally contains 

water. Overlying this formation and encircling the top of the anticline as well as the Zeisman dome is the Embar formation, which in 

thig locality consists of about 400 feet of sandstone, limestone, variegated shale, and gypsum that occurs near the top. In other parts of 

the Bighorn Basin, however, it consists mainly of fossihferous limestone, which contains traces of asphaltum, suggesting that it may, 

where covered, carry oil and gas in commercial quantities, as in the 

vicinity of Lander, Wyo. Owing to the fact that it is exposed along 

the crest of this anticline, any oil that it may have contained has 

doubtless evaporated. Overlying the Embar is the.Chugwater formation ("Red Beds"), which forms the surface rock in a belt a mile or 

more in width on the west, southwest, south, and southeast sides 

and a narrower belt along the northeast side of the anticline. This 

formation, having a thickness of about 1,000 feet, consists mainly of 

red sandstone, with thin layers of shale and a thick bed of g;ypsum 

near the top.

The rocks that remain buried along the crest of the anticline belong 

to the lower part of the Tensleep sandstone, the Amsden formation, 

about 200 feet thick, and the Madison limestone, about 800 feet 

thick, on which the structure contours are drawn. The lower part of 

the Amsden formation is shale and may serve as an impervious cap 

for the Madison limestone lying beneath. Any oil or gas accumulating in the upper part of this limestone probably would have been 

caught and held where the structure is favorable undert the shale 

beds in the lower part of the Am'sden.
SHEKAKD DOME. 105 

CONCLUSIONS.

No drilling has been done on this anticline, and so far as the writer 

is aware there are no oil seeps or gas vents in any part of the upfold. 

The only formation believed to be a possible reservoir for oil or gas 

in this anticline is the upper part of the Madison limestone, which is 

securely sealed by the shale in the lower part of the Amsden formation. The Madison limestone has been carefully tested by the drill 

near Spence, on Big Horn River, just east of Sheep Mountain 40 to 

50 miles to the northwest, but showed small quantities of oil. Probably it is too dense to serve as a good reservoir.

If drilling should be done on this anticline the writer rp.crtTm-np.nflg 

that the first well be located on the west slope of the anticline near 

the crest line, approximately 2 miles southeast of Zeisman's ranch on 

Alkali Fork of Buffalo Creek, as this part of the upfold is the highest and hence best situated for the accumulation of oil or gas. As this 

west slope is hilly some difficulty undoubtedly will be found in transporting drilling machinery.

If a well were drilled near the crest line of the elongated dome on 

the south fork of Brokenback Creek, approximately in the NE. £ 

sec. 28, T. 48 N., R. 88 W., it would, although not at the-highest part 

of the upfold, probably be a good test for this part of the anticline. 

If a well were located here it would be near water for camp use 

and for drilling and also could penetrate the top of the Madison limestone much more easily and at less expense than if located on the 

uplands a mile to the southeast, near the center of the dome.

SHERABD DOME.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Sherard dome l (No. 16, PI. I) is situated in sees. 17-20, 

T. 47 N., R. 89 W., about 8 miles west of Tensleep and 22 miles east 

of Worland. (See fig. 9.) It has been known for 30 years or more 

that oil issued from the ground in a small seep, but no systematic 

work was done till 1914, when six shallow wells found oil from a 

few to as much as 100 feet below the surface. A good road, connecting Tensleep, on No Wood Creek, with Worland, on the Chicago, 

Burlington & Quincy Railroad, lies at the south edge of the dome. 

The surface features consist of low badland hills, bordered on the 

south and west by smooth areas and on the north and east by rougher 

country. Water was found in one of the wells (No. 2, fig. 9) drilled 

in this dome at a depth of slightly more than 200 feet. It is of poor

1 Knight called this dome the "Cottonwood oil field." See Knight, W. C.,and Slosson,E.E., Bonanza, 

Cottonwood, and Douglas oil fields: Wyoming Univ. Bull., Petroleum ser., No. 6, pp. 14-17,1903.
106 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

quality but is good enough for use in the boilers. Cottonwood 

Creek, an intermittent stream, drains the area and throughout the 

greater part of the year contains a small quantity of water in pools 

or seeps which may be used for domestic purposes and for drilling. 

Reservoirs to catch and hold the flood waters could be made easily 

in the beds of shale adjacent to this stream and its tributaries.

Structure contours {lines of equal altitude) Oil well 

on top of Greybull sSnd. Numbers shbw dis- ^ ' 

tance above or below sea level. Interval 200 feet ^as well

FIGURE 9. Structure-contour map of Sherard dome (No. 16, PI. I). The outcrops of sands are mapped

as sandstones.

STRUCTURE.

The Sherard dome, a small northwest-southeast wrinkle on a 

broad westward-dipping slope (see fig. 9), is about a mile long and 

half a mile wide. It lies at a place where the strike of the beds 

swings abruptly from northwest to nearly west. A shallow syncline 

lies a short distance northeast of the crest of the dome and separates 

it from the monoclinal slope on the east. The steepest dips are on 

the south limb of the dome, where one-fourth mile southeast of the 

crest line the beds dip 45° and one-half mile farther southeast 65° S.
SHERARD DOME. 107

Farther south the beds flatten, but continue to dip south and southwest 

for several miles into the deepest part of the Big Horn Basin. The 

dips at the southeast and northwest ends of the dome are very 

slight. On the northeast limb the beds dip in places as much as 

10° but generally less.

The structure contours drawn on the Greybull sand (top of Cleverly 

formation) show the shape and extent of the dome. From these 

and the surface elevations, which range from about 4,500 feet above 

sea level, near Cottonwood Creek, in the NW. £ sec. 18, to about 

4,770 feet in the NW. £ sec. 20, T. 47 N., R. 89 W., the approximate 

depth to the Greybull sand or any other sand whose position with 

relation to the Greybull is known may be obtained. The northwest 

half of the dome is broken by faults of slight throw, two of which 

are shown on figure 9.

The surface rocks belong to the upper part of the Frontier formation, which in this general region is about 550 feet thick. The 

formations which are concealed below the surface but known to 

underlie the Frontier formation down to the Embar limestone are 

the Mowry shale, about 175 feet thick; Thermopolis shale, about 

600 feet thick; Cloverly formation, about 125 feet thick; Morrison 

formation, about 200 feet thick; Sundance formation, about 250 

feet thick; and Chugwater formation, about 1,000 feet thick.

DEVELOPMENT.

Oil has been found in six out of the seven wells drilled on the 

Sherard dome but not in commercial amounts in any of them. 

Well No. 1, drilled in October and November, 1914, in the SW. I 

SE. | sec. 18, is 102 feet deep. The first oil was found at a depth 

of 35 feet, and the well, according to H. M. Sherard, driller, probably 

would yield 7 to 8 barrels daily after being shot. Wells 2-6 are 

situated hi the NW. i sec. 18, T. 47 N., R. 89 W. Well No. 2 contains no oil, but gas was struck at a depth of 25 feet and was found 

in all the strata from this depth to the bottom of the hole at a depth 

of 206 feet. Water of poor quality was found near the bottom. It 

was drilled in November and December, 1914. Well No. 3 was 

drilled to a depth of 102 feet in the same months. The first oil 

was found at a depth of 14 feet and the best flow at about 54 feet. 

Well No. 4, drilled in October and November, 1914, is about 100 

feet deep. The first oil was struck at a depth of about 30 feet, but 

most of it was found 35 feet below the surface. Well No. 5, drilled 

in June, 1915, was also drilled to a depth of 100 feet. The first 

showing of oil was found at 35 feet and the greatest quantity at 70 

feet. It is estimated by the driller, H. M. Sherard, that this well 

will yield 7 or 8 barrels daily after it is "shot." Well No. 6 was
108 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

drilled to a depth of 102 feet in June, 1915, and found its first oil at 

92 feet. It is believed by Mr. Sherard to be as good as wells 1 and 5. 

A sample of oil for analysis was collected from this well. (See analysis 5, p. 51.) Well No. 7, in the NW. £ NW. I sec. 20, T. 47 N., R. 89 

W., was drilled to a depth of 103 feet in June, 1915. The first oil 

was reached at 30 feet and a greater quantity at 65 feet.

The oil from this dome is not so light in weight or color as the 

Greybull and Torchlight oils but is similar to that issuing from the 

seep and well in the Bonanza anticline (p. 96). The fact that 

the oil is heavier than that from other fields in the basin is probably 

due to the fact that the sands yielding oil lie near the surface and 

some of the lighter hydrocarbons may have escaped.

CONCLUSIONS.

The Sherard dome is very small and probably will never be 

important as a producer of oil and gas. The oil, although of high 

grade, is found in such small quantities that it is doubtful if further 

shallow drilling will pay. A deep well testing the Mowry shale and 

Greybull sand might show a greater flow than any of the shallow 

wells. Hence it is advised that a well penetrating at least to the 

Greybull sand, which in the center of the dome lies at a depth of 

about 1,200 feet, be drilled on the southwest or basinward side, on 

which, rather than on the mountainward side, this dome, like the 

Greybull dome and the Lamb anticline, is likely to carry oil.

WELL AREA.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Well area (No. 15, PI. I), so named from the fact that it is 

near a water well drilled on the Worland-Tensleep road, in the central 

part of sec. 21, T. 47 N., R. 90 W., is about 10 or 12 miles west 

of Tensleep, 16 or 18 miles east of Worland, and an equal distance 

southeast of Bonanza. (See PL XIII.) A detailed examination of 

the area was made to determine whether or not it mcluded an anticline or dome which might contain oil or gas, but the information 

collected is in places so conflicting that this point was not settled. 

Nevertheless, it seems advisable to call attention to the locality as a 

possible area for oil or gas and to furnish the reader such information 

as was obtained.

The area is most easily reached from Worland, on the Chicago, 

Burlington & Quincy Railroad, 16 or 18 miles to the west, from which 

a fairly good road extends eastward to Tensleep. By leaving this 

main road at the well in the central part of sec. 21, T. 47 N., R. 90 W.,
U. S. GEOLOGICAL SURVEY \*° BULLETIN 656 PLATE XIII

XT x

(

\ a/m \ \ >" 

\T \ .,^

I VCA I

Structure contours (lines of equal altitude) on top of Grey bull sand. Numbers 

show distance above or below sea level. Solid lines represent accurate contours; 

broken lines, hypothetical contours. Interval 200 feet

Cody shale

sandstone

To p G n'ey b u I Us a n da ton et

-so'oo'

-1000'

Cody shale

MAP OF WELL AREA (No. 15 ON PLATE I) SHOWING STRUCTURE CONTOURS AND 

THREE STRUCTURE "SECTIONS REPRESENTING DIFFERENT INTERPRETATIONS

OF STRUCTURE

The outcrops of sands are mapped as sandstones 

By Charles T. Lupton
WELL AREA. 109

and traveling north 2 or 3 miles by wagon or automobile,- the area 

is reached. It can also be visited by leaving the railroad at Manderson and following an excellent road along the course of No Wood 

Creek to the mouth of Cottonwood Creek. Beyond this the road is 

very poor, and the remaining 6 miles is best traversed on horseback.

The surface of the Well area is comparatively smooth, being cut 

here and there by shallow stream courses which carry water only 

during short periods of the year. To the east and northeast is the 

prominent valley of Cottonwood Creek, bounded on the east by a 

high ridge which forms the west flank of the No Wood anticline 

(p. 97). To the west of the comparatively smooth country constituting the Well area a higher ridge, formed by an outcrop of sandstone and shale, trends northwest. The surface altitudes range from 

about 4,450 feet on Cottonwood Creek, in the northern part of sec. 22, 

T. 48 N., R. 90 W., to about 4,800 feet in the NW. \ NW. \ sec. 17, 

T. 47 N., R. 90 W.

The only water in this region is derived from small seeps which 

issue at a few places in the bed of Cottonwood Creek and of the well 

in the central part of sec. 21, T. 47 N., R. 90 W. During the spring, 

early in summer, and after heavy rains water flows in Cottonwood 

Creek and its intermittent tributaries. Reservoirs could be made 

along these streams with but little difficulty to catch and hold the 

flood waters for drilling and camp use. The shale which forms the 

surface in this locality is nearly impervious, and the possibility of the 

water in the reservoirs escaping through the shale is remote. The 

water in the well above referred to is of poor quality for camp and 

ranch use, as it is highly alkaline, but it could be used, for drilling. 

This well was drilled to a sand at a depth of a little less than 200 feet 

and obtained a fairly good flow of water. Water could undoubtedly 

be obtained from the same sand at many places north and west of its 

outcrop. .

STRUCTURE.

The dips of the beds at the surface are represented on the map 

(PI. XIII) by numerous symbols. The dips east of the top of the 

outcrop of the Torchlight sandstone and west of the base of the 

Mesaverde formation indicate the attitude of the various strata 

beneath the surface, including the Greybull sand (the top sandstone 

of the Cleverly formation), on which the structure contours are 

drawn, because dips in these localities were determined on beds of 

sandstone or upon near-by shale beds. The dips in areas of Cody 

shale between the top of the Torchlight sand (top of Frontier formation) and the base of the Mesaverde formation, however, are not 

believed to indicate reliably the attitude of the Torchlight and other 

sands lying directly beneath. This conclusion was forced on the
110 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

writer by certain inconsistencies. The Cody shale ranges from 3,000 

to 3,300 feet thick at places a few miles from this area both to the 

northwest and the southeast. These thicknesses, which were determined by calculations based on the dips and the width of outcrop, 

correspond closely to the thickness of the shale at other places on 

the east and south sides of the Big Horn Basin. When the same 

means are used to determine the thickness of the Cody shale hi the 

Well area it is found to be a little less than 5,000 feet (see PI. XIII), 

or 1,700 to 2,000 feet thicker than it is a few miles away on either 

side. The writer has no reason to believe that the Cody shale is any 

thicker here than elsewhere. As there is no evidence that the shale 

is thicker here than elsewhere, it is probable either that the surface 

dips of the Cody shale do not indicate accurately the attitude of the 

sands beneath the surface, or that the structure is more complicated 

than it is in most places in Big Horn Basin.

What, then, is the most reasonable interpretation of the surface 

dips? Three hypothetical cross sections (1, 2, and 3, PL XIII) are 

given to show what the writer believes to be the possible structure 

of the rocks in this area. These sections are supposed to show the 

position and dips of the sands according to the various hypotheses.

Hypothetical cross section 1 represents a terrace structure and is 

consistent with the structure contours shown on the map, but does 

not correspond to the d\ s on the shale shown on the map. It is, 

however, the simplest poruc^ure that one can imagine to exist at this 

locality unless J d^^cline is present, a supposition which is probably 

impossible. (See p. i08.) This section corresponds to the structure 

contours on Plate XIII, which are broken in places to indicate that 

their positions are uncertain^

Hypothetical cross section 2 shows the beds in the west half of the 

section to be affected by one upfold. This structure more nearly 

explains the great thickness'of Cody shale than section 1, but it does 

not agree with the surface dips any better than that section. It 

assumes one area of northeastward dips, but no such dips have been 

observed at the surface. If such a structural feature is present, it 

is probable that it would contain oil or gas in commercial quantities, 

as there is no other upfold known between it and the depths of the 

basin to the west.

Hypothetical cross section 3 shows the attitude of the beds beneath the surface if a normal strike fault were present in the area. 

This interpretation would fit all the dips observed along or in the 

vicinity, but no surface evidence of such a fault was observed. As 

faults in shale areas are exceedingly difficult to discover, one may be 

present here without having been detected. If the structure shown 

in section 3 is correct, then the presence of oil or gas in the area would 

probably depend on whether or not the fault has been of such a char-
WELL AREA. Ill

acter as to bring the oil-bearing sands on the west in contact with 

shale in the east, thereby probably sealing the cut edge of the sand 

and rendering it a good receptacle for the storage of oil or gas.

The lowest surface rocks exposed in the northeast corner of the 

area belong to the Mowry shale, a hard, dark-gray, platy shale, which 

includes at least two sandstone beds that carry oil of economic importance in the Torchlight dome a few miles east of Basin. Directly 

overlying the Mowry is the Frontier formation, about 600 feet thick, 

which is mainly beds of sandstone with thin layers of shale and bentonite. This formation contains oil and gas in the Grass Creek, Elk 

Basin, Little Buffalo Basin, and Byron fields, and the writer believes 

it also may carry oil and gas at one or more localities here. Overlying 

the Frontier formation is the light to dark gray Cody shale, about 

3,000 feet thick. Overlying the Cody shale is the Mesaverde formation, consisting mainly of sandstone with thin layers of shale and in 

some localities a .little coal.

Underlying the surface are the lower part of the Mowry shale, the 

Thermopolis shale, the Cleverly formation, and lower formations. 

The Thermopolis shale, about 600 feet thick, is largely dark-gray 

shale, with a bed of sandstone (Muddy sand) about 200 feet above 

its base. Although this sandstone bed is very persistent throughout 

the Bighorn Basin, it is not known to be important as an oil or gas 

reservoir except in the Oregon Basin fielS} ' T)irectly beneath the 

Thermopolis shale is the Cleverly formation, abouu 12 R feet thick, 

which consists usually of about 20 feet of sandr ' ^e'^reybull sand) 

at the top, 70 to 100 feet of variegated shale in'the middle, and zero 

to 25 feet of conglomerate at the base. The Greybull sand is a possible reservoir of oil and gas in this locality, as it carries all the oil 

and gas produced in the Greybull field.

CONCLUSIONS.

Although the writer is unable to point out specifically the crest 

line of any anticline or dome in the area under consideration, yet he 

believes that certain parts of the area are more likely to contain oil 

and gas in commercial quantities than are some of the areas where 

the exact position of the anticlinal crest line is known. A fault may 

cross the area hi a northwest-southeast direction, in which case the 

part of the area lying directly west of the fault probably will be as 

good a reservoir as if an anticline were present, because in the f aulting 

there has been vertical displacement, which may throw sandstone beds 

against beds of shale, and movement along this fault plane which may 

seal the sandstone and prevent any oil or gas that may migrate along 

these beds from escaping to the surface.

If there is no fault through the field, then there may be a structural terrace, as the contours suggest. An accumulation of oil or
112 ANTICLINES IF SOUTHERN PART OF BIG HORN BASIN, WYO.

gas may be found near the line of change of dip, as in many other 

fields.

It is possible also that there may be one or more anticlines or domes 

in this broad area. If these supposed anticlines or domes exist, they 

certainly would be favorable to the accumulation of oil. From present knowledge, however, such folds can not be located. Certain topographic features suggest the possible locations of one or more of these, 

which are given below.

If any one desires to test this area, concerning which the evidence is unusually meager, the writer advises drilling the initial well 

near- the center of sec. 4, T. 47 N., R. 90 W. As may be noted on the 

map, there are no dips shown in this section, which lies opposite the 

prominent reentrant in the outcrop of the Mesaverde formation to 

the southwest. A dip of 3° directly north of the section and dips of 

11° and 12° directly south are suggestive of terrace structure. Another point at which the writer considers drilling may show the presence of oil is in the E. £ sec. 33 and W. £ sec. 34, T. 48 N., R. 90 W., 

southwest of the prominent, bend in the structure contours.

Owing to lack of time to search more carefully for dips hi this locality 

and to the fact that shale dips are not always reliable guides to the 

structure beneath the surface the entire area was not fully examined. 

The writer advises anyone who considers drilling in this locality to 

make a thorough search for eastward and northeastward dips, which 

would suggest that a favorable structure is present a short distance 

west of the locality where such dips are noted.

TENSLEEP ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Tensleep anticline (No. 17, PI. I) is in the northwestern part 

of T. 46 N., R. 88 W., about 5 miles south of Tensleep post office and 

about 30 miles slightly south of east of Worland, a town on the 

Chicago, Burlington & Quincy Railroad. Although it has not been 

tested, it is believed that this anticline offers favorable area for the 

accumulation of oil and gas, because it pitches at each end and is the 

upfold lying nearest the central part of th.e Big Horn Basin. The 

position of an anticline with reference to the main basin is very important, as the long dip slope below the innermost minor fold affords 

a large gathering ground for the oil, whereas anticlines farther up 

the rim of the basin have had their supply cut off by folds lying below them.

The anticline is most easily accessible from Tensleep, which is connected with the railroad by two fairly good roads. One follows 

roughly the course of No Wood Creek from Manderson near the
TENSLEEP ANTICLINE. 113

mouth of that stream through Bonanza to Tensleep, a distance of 35 

or 37 miles. A mail stage traverses this route daily. The other 

route is a few miles shorter but is not so good, as it traverses 

a rougher country. It connects with the railroad at Worland and 

crosses the badlands in a fairly direct line to Tensleep. From Tensleep a second-class road leading to the coal mine in Bud Kimball 

Draw, 10 to 12 miles to the southwest, crosses the northern part of 

the Tensleep anticline.

The crest of the Tensleep anticline (PI. XIV) coincides with a 

troughlike depression which is surrounded by a wall of sandstone 

and shale in places 75 feet high. This wall is encircled by lower 

walls of sandstone due to the outcropping of the harder overlying 

beds which dip away from the crest. Badlands are common in places 

adjacent to stream courses.

The water supply of the anticline is exceedingly meager. There 

are no perennial streams or springs nearer than No Wood Creek, 5 

miles or more to the east. Water for drilling must be brought from 

that stream, which carries an almost inexhaustible supply of fairly 

good water the year round. It is, of course, possible to construct 

reservoirs in the valleys of the intermittent streams to catch and hold 

the spring run-off and floods following heavy rainstorms. At certain times of the year, particularly in spring and early in summer, 

water may be found in the intermittent stream courses.

STRUCTURE.

The Tensleep anticline is a northwestward-trending upfold, and, as 

shown in the cross section (PI. XIV), the steeper dip is on the southwest side. This is a condition not common in the anticlines and 

domes along the east side of the Big Horn Basin, where the steep dips 

usually occur on the east or mountain side. On the southwest limb 

the dips average about 45° but vary from zero near the crest line to 

90° locally at the fault lying about 1£ miles distant. In fact, at one 

place in the E. £ sec. 24, T. 46 N., R. 89 E., the strata are overturned 

and dip 86° toward the east. On the northeast limb the dips are 

less, averaging about 10° but attaining a maximum of 38° locally in 

the eastern part of sec. 18, T. 46 N., R. 88 W. This steep dip occurs 

near a fault and undoubtedly is due to the drag of the beds. The dip 

of the beds on this limb decreases to zero at the trough of the syncline lying about three-fourths mile from the crest line of the anticline. The beds at the northwest end of the anticline dip 8° NW.; 

those at the southeast end, near the north end of Bud Kimball anticline, dip less steeply.

SC133 0 Bull. 656 17 8
114 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

Several strike faults lie nearly parallel to the crest line of the anticline. (See PL XIV.) The largest is about 1$ miles southwest of 

the crest line and is practically parallel to it. The upthrow is about 

200 feet and is on the east side of the fault. This fault is about 5 

miles long and dies out at the southeast in steeply dipping beds. 

The other faults are near the southeast end of the antich'nes and are 

small. The largest fault, just east of the crest line of the anticline, 

raises the east side from 75 or 100 feet above the west. 

* The structure contours drawn on the Greybull sand, at the top of 

the Cloverly formation, show the shape and extent of the anticline. 

From these and from the surface elevations, which vary from about 

4,750 feet above sea level at the southeast end of the anticline, near 

the center of sec. 20, T. 46 N., R. 88 W., to a little more than 4,900 

feet in the eastern part of sec. 18 of the same township, the approximate depth to the top of the Greybull sand, or any other sand 

whose position with relation to the Greybull sand is known, may be 

determined.

The lowest rocks exposed along the crest of the anticline belong to 

the Frontier formation, which in this locality is about 600 feet thick 

and consists of sandstone, sandy shale, shale, and thin beds of bentonite, with sandstone predominating. The lowest sandstone of any 

considerable thickness in the Frontier is the Peay sand, which yields 

the gas and some of the oil in the Lamb anticline. The top sandstone, 

which, in the vicinity of Basin and Greybull, has been named the 

Torchlight sand, is not so thick as the Peay sand and is characterized 

.by a thin bed of conglomerate near its top. Overlying the Frontier 

formation is the Cody shale, which is exposed on the west side of the 

anticline, with two outliers on the east side, one in sees. 6, 7, and 8 

and the other in sees. 19 and 20. The shale is about 3,000 feet thick 

and consists mainly of dark-gray shale, with thin beds of sandstone 

near the top and one lenticular bed near the base. None of these 

sandstone beds, however, is known to contain oil or gas in this part 

of the Big Horn Basin.

There remain buried at the crest of the anticline the Mowry shale, 

about 175 feet thick, the Thermopolis shale, about 500 feet thick, 

and the Cloverly formation, about 125 feet thick. The Mowry shale 

contains in places two oil sands, the Kimball sand above and the 

Octh Louie sand below. Both of these sands, together with the entire 

thickness of the Mowry shale, carry oil in the Torchlight dome. As 

they are only slightly buried in the Tensleep anticline, it is doubtful 

if they contain any oil. The Thermopolis shale consists of dark soft 

shale with a sandstone bed (Muddy sand) about 250 feet above its 

base. This sand is not known to carry oil or gas except in the Oregon 

Basin. The Greybull sand, the top sandstone of the Cloverly formation, is believed to be the most promising oil sand underlying the anti-
U. S. GEOLOGICAL SURVEY

BULLETIN 656 PLATE XIV

Crest of anticline Axis of syncline

Structure contours (lines of equal altitude) on

 top of Greybull sand. Numbers show distance 

above or below sea level. Solid lines indicate 

present position of sand below, and broken 

lines former position above present surface. 

Contour interval. 200 feet.

 . * Geologic boundary

STRUCTURE CONTOUR MAP OF TENSLEEP AND BUD KIMBALL ANTICLINES (Nos. 17 AND 18, RESPECTIVELY, ON PLATE I), AND TWO CROSS SECTIONS

The outcrops of sands are mapped as sandstones 

By Charles T. Lupton

Scale

3 MILES
BUD KIMBALL ANTICLINE. 115

dine, as it is the sand which carries oil and gas in the Greybull field. 

It is in general about 20 feet thick and in texture ranges from medium 

to coarse grain. Underlying it is about 80 feet of variegated shale, 

mainly red in color; and in most places underlying the shale is a bed 

' of sandstone and conglomerate 5 to 25 feet thick.

CONCLUSIONS.

No development work has been done on this anticline, and no oil 

seeps or gas vents on or adjacent to it are known to the writer. The 

anticline as a whole is believed to be worthy of careful consideration 

by oil drillers as a reservoir for oil and gas, as it pitches at both ends 

and lies adjacent to the deeper part of the great basin.

The Greybull sand is believed to be the best oil sand in the anticline, as it is not exposed at the surface at any place, and any oil 

that may have accumulated in its pores has had little opportunity 

to escape. The sandstone beds in the Mowry formation may contain some oil or gas, but are less likely than the Greybull sand to do so, 

for they are near the surface, particularly at the top of the anticline.

The oil sands, where cut by faults, are believed to have been sealed 

by shale, preventing the escape of the oil or gas. Particular attention 

is called to the main fault southwest of the anticline. It has probably 

penetrated as deep as the Cloverly formation; and if so, any oil or gas 

that may have migrated up that stratum from the southwest would 

have entered the sandy beds of the Morrison or Sundance formations 

on the other side of the fault. The overlying sandstone beds of the 

Mowfy and Frontier formations, however, would probably be sealed 

by the Thermopolis shale. (See fig. 6, p. 61.) Special attention is 

called to the possibility that although the Frontier is exposed around 

Tensleep anticline it may carry oil and gas directly west of this fault. 

It is not likely that the fault has completely prevented access of oil 

from the Greybull sand under the Tensleep anticline, because oil and 

gas may have migrated up the strata around the north end of the 

fault into the Tensleep anticline.

Of the different anticlines and domes along the east side of the Big 

Horn Basin southeast from the Torchlight dome that have been described but not tested, the writer considers the Tensleep and the area 

directly west of the main fault to be among the most favorable.

BUD KIMBALL ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Bud Kimball anticline (No. 18, PL I), as shown on Plate XIV, 

lies mainly on the west side of No Wood Creek, 8 to 16 miles south of 

Tensleep post office and in the southeastern part of the Big Horn 

Basin.
116 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

It is most easily accessible from Tensleep post office, and the routes 

to the railroad are fully described on pages 112-113. Beyond Tensleep 

one should follow the River Road to the mouth of Bud Kimball Draw 

or to the mouth of Otter Creek, 6 or 8 miles farther south, from both 

of which secondary roads lead westward and give easy access to the 

entire anticline. Much of the examination, however, must be made 

on foot or horseback as the surface is exceedingly rough in places. 

The River Road connecting Tensleep and Bigtrails crosses the southeast end of the anticline in sec. 31, T. 45 N., R. 87 W., near the mouth 

of Buffalo Creek, a western tributary of No Wood Creek.

The crest of the anticline is marked on the surface by a prominent 

ridge, in which gaps are cut by No Wood Creek near its southeast 

end and by several intermittent streams. (See PI. XIV.) In many 

places near the heads of streams badlands are common, and in a few 

places the streams have worn the rocks in such a way as to form pronounced cliffs.

The main water supply is derived from the perennial streams, No 

Wood and Otter creeks, and from numerous western intermittent 

tributaries of No Wood Creek, which carry water early in spring, 

in summer, and after heavy rains. A few small springs issue from 

the sandstone beds, mainly in the deeper intermittent stream channels on the west limb of the anticline. The greater number occur 

along Buffalo Creek and its tributaries near the southeast end of the 

anticline. Their yield is small, but reservoirs below them would 

probably collect sufficient water for drilling and camp uses. Where 

there are no springs reservoirs could be made in the valleys of the 

intermittent streams to catch and hold flood waters. The best 

water for camp and ranch use, however, is contained in No Wood 

Creek and its eastern perennial tributaries.

STRUCTURE.

The Bud Kimball anticline is a northward-pitching wrinkle on the 

west slope of the great upfold of the Big Horn Mountains. It is 12 to 

15 miles in length, and, like many of the anticlines on the east and 

south sides of the Big Horn Basin, is partly unsymmetrical (see 

PI. XIV), the mountainward side of its southwest half being much 

narrower and the beds more steeply inclined than the basinward 

side. The mountainward limb ranges in width from about onefourth of a mile a short distance southwest of the mouth of Otto Creek 

to about a mile directly south of Bud Kimball Draw. The west 

limb is broad, extending from the crest of the anticline into the 

depths of the great downfold of the Big Horn Basin. On the mountain flank the dips of the beds range from zero at the crest line of the 

anticline to about 76° locally. The maximum dip, which is probably 

due to drag of the beds during faulting, was noted in the W. £ sec. 30,
BUD KIMBALL ANTICLINE. 117

T. 45 N., R. 87 W., near a fault which is less than one-fourth mile 

from the crest line of the upfold. From this point the dips decrease 

gradually northeastward to zero at the axis of the syncline. Near the 

north end of the west limb the dips of the beds range from zero at the 

crest line'to about 65° locally a short distance south of Bud Kimball 

Draw about 1$ miles west of the crest and near the southeast end of the 

prominent fault shown on Plate XIV. This high dip, which is also 

probably due to drag, is on the southwest slope at the southeast end of 

the anticline, about a mile north of the mouth of Buffalo Creek in the 

SW.i sec. 30, T. 45 N., R. 87 W., and within one-fourth of a mile of the 

crest line of the anticline. The north end of the anticline pitches 

slightly into a shallow sag separating it from the Tensleep anticline. 

At the south end the anticline does not pitch south but pitches 

slightly and uniformly northwest, hence the outcrops of the beds of 

rock do not close around the end of the upfold but connect with 

beds outcropping along the west limb of the Big Horn Mountains.

Many small faults are present along this anticline. That to the 

west of the northwest end is described on page 114. In addition to 

the minor faults some of greater magnitude parallel the crest of the 

anticline near its middle. (See PI. XIV.) The throw in places is as 

much as 200 feet. The downthrow of the easternmost fault is on the 

east side, and that of the westernmost, near the crest of the anticline 

almost directly west of the mouth of Otter Creek, is on the west and 

amounts to 100 feet or more.

The structure contours drawn on the top of the Greybull sand 

(top of the Cloverly formation) show the shape and extent of the 

anticline. From these and from the surface altitudes, which vary 

from about 4,575 feet on the river near the mouth of Otter Creek in 

sec. 12, T. 45 N., R. 88 W., to as much as 5,220 feet near the north 

end of the anticline in sec. 4, of the same township, the approximate 

depth from the surface to the sand on which the structure contours 

are drawn or to any other sarids whose relative positions are known 

may be determined. (See p. 39.)

The lowest surface rocks exposed in the Bud Kimball anticline 

belong to the Chugwater formation ("Red Beds"), about 1,000 feet 

thick, which consists mainly of red sandstone but includes a small 

quantity of shale and a thick gypsum bed near the top. This formation is exposed only near the southeast end of the anticline, mainly 

south and east of No Wood Creek. Directly overlying the Chugwater formation is the Sundance formation, about 250 feet thick, 

consisting of sandstone and shale with small amounts of limestone, 

most of which has- a slightly greenish tint. Overlying the Sundance 

is the Morrison formation, about 250 feet thick, consisting of varie- 

 gated shale and sandstone, the shale in most places predominating. 

Directly overlying the Morrison is the Cloverly formation, the top
118 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

sand of which (the Greybull sand) is the bed on which the structure 

contours are drawn. This formation is about 125 feet thick and consists, in addition to the Greybull sand, which is about 20 feet thick, 

of 75 or 80 feet of reddish shale directly underlying the Greybull, and 

of 20 to 25 feet of gray to white conglomeratic sandstone at the base. 

Directly overlying the Cleverly is the Thermopolis sjiale, 500 to 600 

feet thick, consisting of a dark-gray to blue shale with a rather persistent bed of sandstone (Muddy sand) near its middle. This sand is 

not known to contain commercially valuable oil or gas except in the 

Oregon Basin, though it does carry these substances in small quantities wherever it has been penetrated by the drill. Directly overlying the Thermopolis is the Mowry shale, 175 to 200 feet in thickness. It consists of a hard dark-gray platy shale with intervening 

beds of shaly sandstone, which in some localities are recognized as 

sands and which carry oil and gas. This formation produces practically all the oil and gas obtained in the Torchlight dome near Basin. 

Overlying the Mowry is the Frontier formation, 600 feet or more in 

thickness, containing three or four prominent beds of sandstone. 

Two of these, one at the top and the other near the base, have been 

designated as the Torchlight and Peay sands, respectively. In this 

anticline, however, it is impossible to differentiate these beds with 

certainty. Overlying the Frontier is the Cody shale, which, owing 

to the wearing away of the formations by streams, is present only on 

the west flank of the anticline. It is at least 3,000 feet thick and 

contains thin beds of sandstone near its top and in places a bed of 

sandstone near its base. Where present this formation makes an 

excellent cover for the Frontier formation and where the structure is 

favorable, it would probably retain any oil or gas that may have 

accumulated.

The rocks beneath the surface along the axis of the.anticline belong to the lower part of the Chugwater formation, the Embar formation, about 200 feet thick, the Tensleep sandstone, about 400 feet 

thick, and the Amsden formation, possibly a little thinner. The 

Amsden. rests directly upon the Madison limestone, the top part of 

which may possibly carry oil and gas in commercial quantities, but 

this is rather doubtful, as the limestone is so dense in most places as 

to prevent the accumulation of oil or gas in its pores.

CONCLUSIONS.

No drilling has been done on this anticline, and no seeps of oil or 

vents of gas are known at any place along or near its crest. As the 

anticline plunges gradually northwestward and as all the strata from 

the Cody down to and including the upper part of the Chugwater 

formation are exposed along its crest, it seems safe to predict that
MAHOGANY BUTTE ANTICLINE. 119

neither oil nor gas in commercial quantities will be found in these 

formations. It is also doubtful if the Embar can serve as a reservoir 

for oil or gas, because it consists mainly of thin sandstone and shale 

along the southeast side of the Big Horn Basin. The top of the Madison limestone, which is exposed a few miles to the east and southeast, 

is an equally poor reservoir because of .its compact character.

MAHOGANY BUTTE ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Mahogany Butte anticline (No. 19, PI. I) is a deeply eroded 

upfold, the western part of which is in the area represented on Plate 

XV. All rocks known to carry oil or gas at any place in Wyoming 

are exposed along the valley of No Wood Creek near the top of the 

anticline. This fact and the proximity to the Big Horn Mountains 

make the anticline one of doubtful value as an oil or gas reservoir 

except at its west end in the east part of T. 43 N., R. 89 W., where 

there is a flattening of the dips.

The anticline lies mainly in T. 43 N., Rs. 88 and 89 W., west of 

No Wood Creek. It is in the southeastern part of "the Big Horn 

Basin and on the south side of the deep part of the basin.

The nearest railroad town is Lucerne, on the Chicago, Burlington 

& Quincy Railroad, 40 miles west. From this place a good road 

follows the valley of Kirby Creek and a second-class road leads up thevalley of Lake Creek to its head, thence over the divide across the 

upper drainage of No Water Creek and on the east to this anticline 

and the settlements along No Wood Creek. A stage road connects 

Bigtrails, a post office a few miles northeast of Mahogany Butte, 

with Manderson, a small town on the Chicago, Burlington & Quincy 

Railroad at the mouth of No Wood Creek about 55 miles to the northwest. The latter route, although longer, is probably the most advisable 

unless one (iesires to follow the less frequented road from Lucerne 

and thus see along the route other anticlines described in this report.

The greater part of the Mahogany Butte anticline lies west of 

the deep valley of No Wood Creek, and the surface near by contains 

many rugged hills 1,000 to 1,200 feet high. Farther from.the stream 

the valleys are shallower and the hills less rugged. Mahogany 

Butte, a conical mass of Madison limestone and overlying formations, 

is the most conspicuous topographic feature of the locality. The 

surface of the anticline varies in elevation from about 6,430 feet 

above sea level at the top of Mahogany Butte (PI. X, B, p. 98) to 

about 5,150 feet at the northwest end of the anticline near Buffalo 

Spring Creek in sec. 15, T. 43 N., R. 89 W.
120 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

Water may be obtained from No Wood Creek, a perennial stream 

that crosses the anticline, and from springs mainly along the outcrop of sandstone beds on the north side of the upfold,. Intermittent streams and reservoirs that could be made in the shallow valleys would provide an additional supply. As drilling is most likely 

to be done at some distance from No Wood Creek rather than close 

to that stream, water is best procured from the springs, the valley 

of No Wood Creek being too deep to make pumping practicable.

STRUCTURE.

The Mahogany Butte anticline (PI. XV) is an unsymmetrical 

upfold about 15 miles long and 8 to 10 miles wide. Its highest 

point is near Mahogany Butte at the east edge of the area. It trends 

in general northwest-southeast, but in sees. 23-25, T. 43 N., R. 89 W., 

it trends more nearly north. The steepest dips are on the northeast 

limb, where a maximum of 54° just west of Buffalo Creek in the SE. | 

sec. 14, T. 43 N., R. 89 W., was measured. The beds near the crest 

dip very gently but become rapidly steeper one-fourth to one-half 

a mile away, particularly at the northwest end. Directly east of 

No Wood Creek the anticline rises abruptly at the butte, the top of 

the Madison limestone being several hundred feet above the river 

level. Immediately east of the top of Mahogany Butte the anticline slopes gently to the southeast. Directly west of No Wood 

Creek the anticline is probably nearly level, but 7 or 8 miles west of 

the river it pitches rapidly to the northwest.

Where the strata begin to dip more strongly toward the northwest 

oil and possibly gas may have accumulated in the rocks. On the 

northeast limb of the anticline there is a small parallel upfold in 

sees. 17, 18, 20, and 21, T. 43 N., R. 88 W., and sees. 12 and 13, 

T. 43 N., R. 89 W., but it probably contains no oil, as it pitches 

northwest and is broken by a fault about 2 miles in length, the throw 

of which is in places 300 to 400 feet.

Structure contours drawn on the Greybull sand show the shape 

of the anticline. From these and from the surface elevations the 

approximate depth to the Greybull sand or to any other sand whose 

relation to the Greybull is known may be determined. (See p. 39.)

The lowest rocks exposed at the east end of the part of the anticline lying west of No Wood Creek belong to the Chugwater formation. Overlying it are the Sundance and Morrison formations, which 

are not known to carry oil in this region. Overlying the Morrison is 

the Cleverly formation, about 125 feet thick, the uppermost sandstone of which (the Greybull sand) may serve as a reservoir for oil 

or gas, as it is the oil and gas bearing sand of the Greybull field. 

Above the Cleverly is the Thermopolis shale, having a thickness of
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XV

MAHOGANY BUTTE

ANTICLINE Structure contours (lines 

of equal altitude) on top 

of Greybull sand. Numbers show distance 

above sea level. Solid 

mes indicate present 

position of sand below, 

and broken lines foriier 

position above present 

surface. Interval,£00 ft.

Butte

STRUCTURE CONTOUR MAP OF THE GREATER PART OF MAHOGANY BUTTE ANTICLINE (No. 19 ON PLATE I)

AND CROSS SECTION

The outcrops of sands are mapped as sandstones

By Charles T. Lupton
LYSITE MOUNTAIN ANTICLINE. 121

about 500 feet and bearing near its middle a sand that, although not 

productive of oil in the Big Horn Basin, has been named the Muddy 

sand. The Frontier formation carries oil and gas in the Grass Creek 

and Little Buffalo fields, and the Mo wry shale bears these substances in 

the Torchlight dome, but it is doubtful if these beds contain them 

here. If ahole were drilled in the northern part of sec. 15, T. 43 N., R. 

89 W., on Buffalo Springs Creek, it would penetrate the following 

beds in order to reach the^Greybull sand, which, as stated above, is 

the most promising oil sand in the anticline, although the Mowry 

may contain small quantities of oil or gas:

Rocks below the surface and above the Greybull sand in sec. 15, T. 43 N., R. 89 W.

Feet.

Frontier formation, sandstone and shale, sandstone predominating..... ................................................. 600±

Mowry shale, bluish gray, hard, platy shale, with two or more 

sandstone beds.............................................. 200+

Thermopolis shale, dark shale with sandstone bed about 250 feet 

above base (Muddy sand).................................... 500+

CONCLUSIONS.

No drilling has been done on the Mahogany Butte anticline. The 

north limb is faulted, but faults do not always produce unfavorable 

conditions for the accumulation of oil and gas. That part of the 

structure east of No Wood Creek seems to be of no value, as the limestone (Embar), which in places carries oil, is well exposed on three 

sides of Mahogany Butte. West of No Wood Creek for 4 or 5 miles 

oil or gas may be found in the Embar limestone, but this is doubtful, 

as any oil or gas that was originally in this limestone probably would 

have migrated through the strata up the rise to the northeast and 

have escaped at the surface. If a well is to be drilled on this anticline the writer would recommend some point near the crest line in 

sec. 15, T. 43 N., R. 89 W., where the beds seem to flatten, forming a 

structural terrace. A 1,200 to 1,400 foot hole probably would penetrate the Greybull sand at this place.

LYSITE MOUNTAIN ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Lysite Mountain anticline (No. 20, PL I) trends northwestsoutheast in the central part of T. 42 N., R. 90 W., at the southeast 

end of the Black Mountain anticline (p. 123). It is so named 

because its southeast end pitches under Lysite Mountain, where it 

is obscured by Tertiary rocks, which overlie it and which are not
122 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

folded in conformity with it. (See PI. XVII, p. 126.) No drilling 

has been done on this anticline; but an oil seep near its crest line in 

sec. 21 and the shape of the anticline suggest that it may contain oil 

and gas.

The nearest railroad point is Lucerne, on the Chicago, Burlington 

& Quincy Railroad near Big Horn River, about 27 miles to the west. 

From this place a good road follows the valley of Kirby Creek to 

the mouth of Lake Creek, thence up that stream by means of a secondclass road to its head, and thence over the divide a few miles to the 

northwest end of the anticline.

The surface near the anticline is characterized by canyons cut into 

the sandstone beds by the streams tributary to No Water Creek. 

Its entire surface is rugged, ranging from hilly to mountainous.

Water for drilling and for camp use is abundant in springs and small 

ponds along the north front of Lysite Mountain. It is less abundant, 

however, at the northwest end of the anticline than along the southeast two-thirds of it. This water is of excellent quality and is better 

than any found in the springs farther from the mountain front.

STRUCTUKE..

The Lysite Mountain anticline is about 4 miles long, and its southeast end is covered by the rocks that form the top of Lysite Mountain. 

(See PI. XVII.) Its northeast limb slopes regularly into a small 

syncline with an average dip of about 30° but its southwest limb is 

steeper, the beds averaging 45° or more and reaching a maximum 

dip of 72° locally near the fault. The width of the southwest limb 

is generally less than half a mile, and that of the northeast flank is 

several miles. The section shown on Plate XVII cuts the fold 

obliquely and does not show its true shape. The anticline is broken 

by a fault which crosses the crest obliquely near the middle and 

offsets it about one-fourth mile. The downthrow is on the southwest side and amounts to about 100 feet. The shape of the southeast 

end of the anticline is unknown, as it is covered unconformably by 

rocks of Tertiary age.

The surface rocks of the Lysite Mountain anticline belong to the 

Mowry shale, about 250 feet thick, and to the Frontier formation, 

about 600 feet thick. The Mowry contains hard, platy dark-gray 

shale with numerous fish scales, and the Frontier is mainly beds of 

sandstone with interbedded shale and sandy shale. The oil seep in 

sec. 21 is in one of the lower beds of the Frontier formation and may 

be interpreted in two possible ways: It may indicate that oil in larger 

or smaller quantities occurs in the anticline and that some of it has 

migrated through the rocks to the surface; or it may mean that a 

small quantity of oil is being formed in the rocks beneath and is 

reaching the surface as fast as it is formed.
BLACK MOUNTAIN ANTICLINE. 123

The formation directly underlying the Mowry is the Thermopolis 

shale, which is about 400 feet thick in this part of the Big Horn Basin. 

Near the middle of this shale there is a persistent bed of sandstone 

known in other parts of the region as the Muddy sand. It is not 

known to contain oil or gas in commercial quantities, although in 

places it contains traces of these substances. Directly underlying 

the Thermopolis shale is the Cleverly formation, the top sandstone 

of which the Greybull sand is the reservoir in which oil and gas 

occur in the Greybull field, and is believed to be that in which oil 

and gas are most likely to be found in the Lysite Mountain anticline.

CONCLUSIONS.

It is difficult to determine the value of this anticline as a possible 

reservoir for oil or gas. Its value depends largely on whether the 

southeast end of the anticline pitches southeast or whether it rises 

and merges with the north flank of the great upf old lying to the south, 

and this can not be determined because the south end of the anticHne 

is concealed by horizontal Tertiary beds. Should any one decide to 

test it the most favorable point at which to drill is probably near the 

central part of sec. 21, T. 42 N., R. 90 W., as this point is near the 

crest line of the anticline and also near water for drilling and camp use.

BLACK MOUNTAIN ANTICLINE. 

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Black Mountain anticline (No. 21, PL I), mainly in the southeastern part of T. 43 N., R. 91 W., is a northwestward-trending fold 

near the south edge of the Bighorn Basin. It has not been tested for 

oil or gas, but both its shape (PI. XVI, A) and the absence of known 

anticlines between it and the deeper part of the Big Horn Basin 

suggest that it may contain oil or gas.

Lucerne, about 25 miles to the west, on the Chicago, Burlington & 

Quincy Railroad, is the nearest railroad point. From it a good road 

leads up Kirby Creek to the mouth of Lake Creek, where it connects 

with a second-class road that 'follows the valley of Lake Creek to 

its head, crosses the divide into the drainage of Mud Creek, and 

follows along the south side of the Black Mountain anticHne.

The principal surface feature of the anticHne is a prominent ridge 

known as Black Mountain (PI. XVI, A), the northwest end of which 

is cut by Mud Creek. In places the south limb is carved into badlands; elsewhere there are nearly impassable cliffs, and Black Mountain can be ascended from the south at a few places only. The north 

side is more gentle and is more easily ascended, but it is deeply
124 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

eroded by streams tributary to No Water Creek. The top of Black 

Mountain nearly coincides with the crest line of the anticline. Its 

surface ranges in altitude from about 6,170 feet in sec. 6, T. 42 N., 

R. 90 W., to about 4,875 feet along Mud Creek near the crest line in 

sec. 27, T. 43 N., R. 91 W. From these altitudes and from the structure contours (PL XVII, p. 126) the approximate depth and thickness 

of the rocks that must be penetrated by the drill to reach the possible 

oil-bearing sands may be determined. (See p. 39.)

The water supply is meager. The only perennial spring is one at 

Shoemaker's ranch in the SW. £ sec. 36, T. 43 N., R. 91 W., and it 

flows barely enough for ranch use and can not be depended on to 

furnish water for drilling. Water from a number of good springs 

which flow into natural ponds a few miles to the south along the north 

front of Lysite Mountain could be piped down the ^lope to the south 

side of Black Mountain. Reservoirs to catch and hold the flood 

waters of Mud Creek could be made and probably would be the most 

economic means of obtaining water for drilling. Water for camp use 

must be hauled or piped from the springs or ponds to the south.

STRUCTURE.

The Black Mountain anticline is about 5 miles long and is unsymmetrical (PI. XVII, p. 126), the dips on the south side being much 

steeper than those on the north side, and the south limb is consequently 

much narrower than the north. The south limb is, in fact, less than 

half a mile in width^ and the north limb several miles, extending from 

the crest line of Black Mountain anticline probably to the deeper 

part of the great syncline of the Big Horn Basin. . The dip of the beds 

on the north limb ranges from 25° at the steepest place to 8° at points 

6 to 7 miles to the northeast.

Structure contours drawn on the Greybull sand, the top sandstone 

of the Cloverly formation, show hi general the shape of the anticline. 

From these contours and from the surface elevations given above the 

thickness of strata the drill must penetrate to reach the Greybull 

sand or any other bed whose position with relation to the Greybull 

sand is known may be closely determined. (See p. 39.)

The Black Mountain anticline is nearly parallel to the near-by 

Lysite Mountain anticline to the southeast and the Lake Creek 

anticline to the northwest. Its northwest end is within one-half 

mile of the Lake Creek anticline, from which it is separated by a 

narrow steep-sided syncline.

The most prominent fault or break in the rocks is in sec. 5, T. 42 

N., R. 90 W., at the southeast end of the anticline. It is parallel 

to the crest line of the anticline and has a downthrow of about 150 

feet on the south side. It does not form an outlet for any oil or gas 

below, as no oil seeps or gas vents are present in or near it.
U. S. GEOLOGICAL SURVEY

A. BLACK f,' UM A ; ANTICLINE, LOOKING NORTHWEST.

B. FAULT TRACE AT EAST END OF RED SPRING ANTICLINE, NEAR THERMOPOL1S.
LAKE CREEK ANTICLINE. 125

The surface rocks of Black Mountain are the Mowry shale, a hard 

dark-gray platy shale about 200 feet thick, and the Frontier formation, 500 to 600 feet thick, which is mainly of sandstone and sandy 

shale. The Frontier is overlain by the Cod^ shale, about 3,000 feet 

thick. The lowest beds exposed along the crest of the anticline 

belong to the upper part of the Mowry shale, which is underlain by 

the Thennopolis shale, about 400 feet in thickness, with a persistent 

bed of sandstone near the middle. Directly underlying the Thermopolis shale is the Cleverly formation, the top sandstone of which 

the Greybull sand carries oil and gas in the Greybull field and may 

do so in the Black Mountain anticline.

CONCLUSIONS.

The Black Mountain anticline appears to be favorable for the 

accumulation of oil and gas, but it has not been drilled and so far 

as known has no oil seeps nor springs. From conditions in other 

areas it seems probable that the best place to drill lies along the 

north flank near the crest of the anticline, because any oil that it 

may contain probably has migrated or is migrating up the long 

slope from the bottom of the basin and is likely to find lodgment 

before it reaches the crest of the upfold. Hence the writer recommends that a well be drilled a short distance north of the crest line 

in the south and highest part of sec. 36, T. 43 N., R. 91 W. The 

Greybull sand at this place will probably be reached at a depth of 

about 1,300 feet. Considerable difficulty will undoubtedly be experienced in bringing drilling machinery, as the place is on a high 

rugged ridge.

LAKE CHEEK ANTICLINE.

By CHARLES T. LUPTON.

GENERAL FEATURES.

The Lake Creek anticline (No. 22, PL I) is in the southern part of 

the Big Horn Basin, mainly north'of Lake Creek in T. 43 N., Rs. 

91 and 92 W., T. 44 N., R. 92.W., and T. 42 N., R. 91 W. It has 

not been tested for oil and gas, but its shape and relation to the 

deeper part of the great basin suggest that it may contain these 

substances. (See PI. XVII.)

Lucerne, on Big Horn River, on the Chicago, Burlington & Quincy 

Railroad, about 20 miles to the west, is the railroad point from 

which this anticline can be visited most easily. From this place the 

route lies over a good road up the valley of Kirby Creek as far as the 

mouth of Lake Creek and from that point over a second-class road 

which extends the entire length of the anticline, lying for the most 

part within one-fourth of a mile of its crest line.
126 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

The anticline coincides with a ridge, which is cut in a number of 

places by small streams. Badlands are common in the shale on the 

north side, and on the south side the surface is broken by many 

cliffs formed by the wearing away of the sandstone beds by Lake 

Creek. The ridge ranges from 200 to 400 feet above the surrounding country, and the cliffs along Lake Creek are in many places 

impassable.

Water for drilling and domestic use is scarce, as Lake Creek is an 

intermittent stream and the few springs are somewhat alkaline and 

have a small flow. The best spring known on or near the anticline 

is at the K I S ranch in the SW. i sec. 13, T. 43 N., R. 92 W. Another spring of smaller flow is at the Auterbach ranch, in the NE. \ 

sec. 33, T. 43 N., R. 91 W. The amount of water furnished by 

these and poorer springs is not sufficient for drilling and camp use, 

and water for these purposes would have to be stored in reservoirs at 

times when Lake Creek carries water or be hauled or piped from 

springs or ponds along the north front of Lysite Mountain, 4 to 10 

miles to the south. Water will undoubtedly be found in drilling in 

the sandstone beds outcropping along the anticline but will probably 

be in small quantities.

STRUCTURE.

The Lake Creek anticline, which trends northwest-southeast, is 

about 9 miles long and the steepest limb is on the southwest side. 

(See PI. XVII.) The average dip on this side is about 50° near the 

crest line, but in the SW. I sec. 28, T. 43 N., R. 91 W., a maximum 

local dip of 69° was observed. The north side of the anticline is 

broad, and the northeastward dip probably extends from the crest 

line to the bottom of the great syncline of the Big Horn Basin, 

except at the southeast end, where it is interrupted by the Black 

Mountain anticline. Here the. north side is less than one-fourth of 

a mile wide, about the same as the width of the south side. The 

maximum dip noted on the north near the K I S ranch, within onefourth of a mile of the crest, is 25°. From this point the dips gradually decrease toward the northeast.

The shape and extent of the Lake Creek anticline are shown by the 

structure contours drawn on the Greybull sand and by the cross section (PI. XVII). The surface elevations range from about 4,535 feet 

on Lake Creek near the center of sec. 9, T. 43 N., R. 92 W., to about 

5,375 feet near the center of sec. 34, T. 43 N., R. 91 W. From these 

and from the structure contours the approximate depth to the Greybull sand at any point shown on the map can be ascertained. (See 

p. 39.)

The oldest rocks exposed on the surface of the anticline belong to 

the Frontier formation, which for the most part is sandstone with 

smaller amounts of sandy and clay shale. The formation is about
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XVII

Ss===r:^'\

s££?^+40o- ->

STRUCTURE CONTOUR 'MAP OF LYSITE MOUNTAIN, BLACK MOUNTAIN, AND LAKE CREEK ANTICLINES (Nos. 20, 21, AND 22, RESPECTIVELY, ON PLATE I) AND TWO STRUCTURE SECTIONS

The outcrops of sands are mapped as sandstones 

By Charles T. Lupton
WILDHORSE BUTTE ANTICLINE. 127

600 feet thick and includes the rocks from which issue the springs of 

the anticline. The Frontier formation is overlain by about 3,000 feet 

of the Cody shale, which fringes the Lake Creek anticline. Directly 

underlying the Frontier formation is the Mowry shale, about 200 feet 

thick, which contains one or two sandstone beds that may serve as 

reservoirs for oil and gas, as they do in the Torchlight dome. The 

formation is characterized by great numbers of fish scales and by 

hard dark-gray platy shale which constitutes the greater part of 

the formation. Underlying the Mowry shale is the Thermopolis 

shale, which is about 400 feet thick in this part of the Big Horn 

Basin, and which includes one bed of sandstone near the middle 

known as the Muddy sand. Although this sandstone is remarkably 

persistent, it is not known to carry oil or gas in commercial quantities at 

any place in the Big Horn Basin except in the Oregon Basin, where 

the gas is thought to come from the Muddy sand. Directly underlying the Thermopolis shale is the Cloverly formation, the top sandstone of which the Greybull sand, on which the structure contours 

are drawn is believed to be the most promising reservoir for oil and 

gas in the anticline.

CONCLUSIONS.

The Lake Creek anticline is a sharp flexure, and therefore is not an 

ideal fold to serve as a reservoir for the accumulation of oil and gas, 

but some of the sands that are productive in other parts of the Big 

Horn Basin are below the surface here, and, as the anticline pitches 

at both ends, it is possible that they may be found to contain oil or 

gas. Two of these sands (Kimball and Octh Louie) are in the Mowry 

shale, but the bed that is most likely to be productive is the Greybull 

sand, which lies 1,000 to 1,200 feet below the surface along the anticline and is known to be one of the most important sands of Big 

Horn Basin, being the one from which oil and gas are obtained in 

the Greybull field.

It is believed that the most favorable part of the anticline is the 

north limb, where the structure is broader and the rocks dip less 

steeply than they do on the south limb. The writer therefore suggests that the best place for a test wejU is on the highest part of the 

anticline, north of Lake Creek, in sees. 28 and 29, T. 43 N., R. 91 W. 

Water for drilling and camp use can be obtained at Auterbach's 

spring in this vicinity.

WILDHORSE BUTTE ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Wildhorse Butte anticline (No. 23, PI. I) lies on a high ridge 

mainly in the northeastern part of T. 42 N., R. 93 W., south and 

southeast of Wildhorse Butte. (See PI. XIX, p. 134.) It is a small
128 ANTICLINES IN SOUTHERN PAET OF BIG HORN BASIN, WYO.

northward-pitching wrinkle on the north flank of Bridger Mountain, 

and hence is probably of little value as a reservoir for oil and gas. 

It is accessible with difficulty, as no wagon road leads to any part of 

it. Thermopolis, about 11 miles to the west, is the nearest railroad 

station. A second-class road extending east several miles from that 

town is the easiest route, but the last few miles must necessarily be 

made on foot or horseback.

The surface of the anticline is characterized by a shallow troughlike depression in the rocks, which widens and deepens toward the 

southeast, where it merges with the valley of Buffalo Creek on the 

north flank of Bridger Mountain. Hogback ridges lie parallel to the 

crest line of the anticline and form the sides of the surface depression. 

The rocks of the upfold are cut by streams which have worn comparatively deep channels, mainly parallel to the crest line of the anticline 

and about one-fourth mile southwest of it.

Water for ranch and camp use and for drilling is scarce but may 

be obtained from springs in the valleys, either to the north or the 

south. As it is doubtful if drilling will be done on this anticline the 

question of water for.such purposes is of little importance.

STRUCTURE.

The Wildhorse Butte anticline is an unsymmetrical upfold about 

3 miles long, with its broad limb on the northeast, a condition that is 

characteristic of most anticlines along the south side of the Big Horn 

Basin. (See PI. XIX.) The dips on the southwest limb are steepest 

at the north end, where they range from zero at the crest line to as 

much as 49° near Wildhorse-Butte, 200 to 300 feet distant, beyond 

which they decrease southeastward to 36° hi a distance of 2£ miles. 

Southwestward from the line of steepest dips the beds gradually 

flatten to zero at the trough of the syncline one-fourth of a mile to a 

mile distant. To the north the dips range from zero at the crest line 

of the anticline to a maximum of 36° about one-fourth of a mile 

away, beyond which they gradually flatten to the axis of the syncline 

or downfold. The steep dips on the south side necessarily make 

that limb much narrower than the northern, which is about 2 miles 

wide.

The lowest rocks exposed in the anticline belong to the Chugwater 

formation, which contains about 1,100 feet of red sandstone and 

shale, with a thick bed of gypsum near the top. Overlying- these 

beds, on the limbs of the anticline, are the Sundance, Morrison, and 

Cleverly formations, Thermopolis and Mowry shales, and Frontier 

formation. Underlying the Chugwater formation and not exposed 

are the Embar, Tensleep, and Amsden formations and Madison 

limestone.
BLUE SPRING ANTICLINE. 129

Structure contours on the top of the Greybull sand show the shape 

of the anticline. From these and from the surface elevations, which 

range from about 5,000 to 6,000 feet, the depth to the Embar limestone or any other bed whose relation to the Embar is known may 

be determined.

CONCLUSIONS.

The beds that outcrop in the northwest part of the Wildhorse Butte 

anticline are eroded at the southeast end, and as it pitches northwest throughout its length it is very doubtful if oil or gas in commercial quantities would have been retained if ever present in any 

of the sands. The writer advises against the expenditure of money 

in drilling in this anticline.

BLUE SPUING ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Blue Spring anticline (No. 24, PI. I), situated mainly in the 

southeastern part of T. 43 N., R. 93 W., and the southwestern part 

of T. 43 N., R. 92 W., is about 4 miles long and trends in general 

northwestward. (See PI. XIX, p. 134.) It may contain oil and gas, 

but it has not been tested.

The nearest railroad points to this anticline are Lucerne, about 

10 miles to the northwest, and Thermopolis, about 12 miles to the 

west, both on Big Horn River. Lucerne is the more convenient 

point of approach. A good road extends from Thermopolis north 

6 or 7 miles to Lucerne and thence eastward up Kirby Creek. From 

this road, at a point about 3 miles west of the mouth of Lake Creek, a 

second-class road extends southward to the highest part of the 

anticline.

A depression, in places 200 to 300 feet deep, coincides with the 

crest of the anticline and is locally bounded by inward-facing walls 

of shale and sandstone cut by canyons. In places, however, the 

depression is not conspicuous. The limbs of the anticline are for 

the most part marked by steep slopes of sandstone. The surface 

is hilly, and badlands are present where streams have worn into 

the shale.

Water is plentiful near this anticline and the quality is good. 

The best springs issue from the beds of sandstone that are upturned 

around the flanks of the fold. They are naturally more abundant 

in the principal valleys in sees. 24 and 25, T. 43 N., R. 93 W., and 

in sees. 29, 32, and 33, T. 43 N., R. 92 W., than elsewhere. Water 

also flows in the upper course of the main valleys at the west end of 

86133° Bull. 656 17 9
130 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

the anticline throughout the greater part of the year, and abundant 

supplies for drilling and camp purposes are present or near at hand 

in all parts of the anticline.

STRUCTURE.

The Blue Spring anticline has the general shape of a reversed 

letter S. Its length is about 4 miles and the south limb is very much 

narrower than the north, for the former is about half a mile and the 

latter is as much as 5 miles in width. The south limb is steeper 

than the north, its maximum dips being about 20°, whereas those 

of the north limb reach a maximum of only 12°, in the southern 

part of sec. 19, T. 43 N., R. 92 W. (See PI. XX.)

The anticline is closely associated with a larger upfold farther 

west, known as Red Spring anticline. The two upfolds do not connect directly, but their north limbs merge into the general dip toward 

the central part of the Big Horn Basin. The only faults known in or 

adjacent to this anticline are one of small throw mainly in sec. 30, 

T. 43 N., R. 92 W., on the north flank of the Blue Spring anticline and 

another at the east end of the Red Spring anticline, about a mile 

west of the upfold here described. (See PI. XVI, B, p. 124.)

The surface rocks of the Blue Spring anticline belong to the Thermopolis shale, Mowry shale, and Frontier formation. Only the 

lower part of the Thermopolis shale is below the surface, the upper 

part as well as all of the Mowry shale and Frontier formation being 

visible in outcrop in the anticline. The Thermopolis shale is about 

400 feet thick and near the middle contains a thin but persistent 

bed of sandstone known as the Muddy sand, which, however, is not 

known to contain oil and gas in commercial amounts in any part 

of the Big Horn Basin except in the Oregon Basin. The Mowry shale, 

directly overlying the Thermopolis, is 200 to 300 feet thick and 

consists mainly of hard dark-gray platy shale with layers of sandstone interbedded, all containing fish scales in great abundance.

The formation underlying the Thermopolis shale can not be seen 

in the anticline but can be studied in the Red Spring anticline and 

in other parts of the Big Horn Basin. The uppermost formation is 

the Cloverly, about 125 feet thick. Its upper bed of sandstone, the 

Greybull sand, which carries oil and gas in the Greybull field, is 

believed to be the most probable reservoir of oil and gas in this 

anticline. It is about 20 feet thick and is underlain by variegated 

beds of shale and sandy shale. Directly underlying this shale .and 

forming the base of the formation is a conglomeratic sandstone about 

30 feet thick.

The structure contours drawn on the top of the Greybull sand and 

the cross section (PI. XIX) show the shape of the anticline and its
ZIMMERMAN BUTTE ANTICLINE. 131

relation to the adjacent upfolds. From the structure contours and 

the surface elevations the depth to the different sands may be approximately determined. (See p. 39.) In the Blue Spring anticline the 

surface elevations range from about 4,680 feet in the N. £ sec. 24, 

T. 43 N., R. 93 W., to about 5,390 feet in the NE. J sec. 31, T. 43 

N., R. 92 W.

CONCLUSIONS.

The Blue Spring anticline has not been drilled, and no seeps of 

oil or asphaltum are known in or adjacent to it. Although the 

west half of the anticline is nearly level, it 1 is believed to be a possible 

reservoir of oil and gas. In the writer's opinion the most favorable 

places for drilling are along the crest on the upland in the northern 

part of sec. 31, T. 43 N., R. 92 W. Water for drilling would have to 

be hauled 1 or 2 miles and fuel would have to be brought from the 

coal mines near Big Horn River in the vicinity of Gebo and Crosby. 

The Greybull sand at this place is probably not more than 350 

feet below the surface.

ZIMMERMAN BUTTE ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

In a small area south and west of Zimmerman Butte, north of 

Kirby Creek and from 6 to 10 miles east of Big Horn River, there is a 

small anticline (No. 25, PL I) which is here called the Zimmerman 

Butte anticline. (See PL XVIII.) The observed fold has a length 

of only about 2 miles, but it possibly extends 4 or 5 miles farther 

northwest and may contain oil or gas. The bedrock in the doubtful 

area is shale, in which dips are exceedingly difficult to detect, and it 

was impracticable to obtain sufficient data to determine whether or 

not the anticline is present here, and, if present, whether it probably contains oil or gas.

This area is easy of access, as it lies directly north of the welltraveled road connecting Thermopolis and Lucerne with Lost Cabin 

and Casper. The road follows the west side of Big Horn River from 

Thermopolis to Lucerne, where it crosses the river and ascends Kirby 

Creek along the south side of the Zimmerman Butte anticline. The 

greater part of the area can be traversed by vehicles.

The area is bounded on the south by the valley of Kirby Creek 

and on the north by prominent sandstone cliffs. The highest part 

of these cliffs, in the NE. \ sec. 25, T. 44 N., R. 93 W., is known as 

Zimmerman Butte. The area lies between Kirby Creek valley and 

Zimmerman Butte and has for the most part a smooth surface, here 

and there broken by badlands along the streams.
132 ANTICLINES IN SOUTHEEN PAET OF BIG HORN BASIN, WYO.

The available water supply is from Kirby Creek and a few seeps 

that issue at points along its course. Throughout the dry season the 

supply is extremely meager, and water for drilling and camp purposes 

must be hauled from Big Horn River several miles to the west or from 

springs along the north limbs of Blue and Red Spring anticlines, 

about the same distance to the south. Reservoirs could be made with 

little difficulty in the stream courses and water caught and held for 

use during the dry season.

STRUCTUEE.

The small but well-defined anticline along Kirby Creek near the 

southeast corner of T. 44 N.,- R.°93 W. (PL XVIII), was followed 

northwest as far as the SE. | sec. 35, T. 44 N., R. 93 W., but beyond 

that no dips were obtained, owing to the flatness of the surface and 

the absence of exposures of the shale. The continuation of the anticline to the northwest is therefore uncertain. The presence of a linear 

anticline or.dome farther to the northwest is suggested by the incurving escarpment of the Mesaverde through sees. 23, 22, 15, 16, 17, 

18, and 19, T. 44 N., R. 93 W., but the dips noted in the shale south of 

this escarpment are not so located as to make it possible to determine 

whether the anticline observed near the southeast corner of the township continues to the northwest, as suggested on Plate XVIII, B, 

whether a separate upfold lies to the northwest, or whether the rocks 

gradually dip from sec. 33 to and beyond sec. 16, T. 44 N., R. 93 W., 

as shown on Plate XVIII, A.

The hypothetical structure contours on Plate XVIII, A, suggest a 

general dip of the rocks from south to north from a point a mile or 

more south of Kirby Creek to the outcrop of the Mesaverde rocks 3 

miles or more to the north. Along the north flank of Red Spring 

anticline, a few miles south of Kirby Creek, the top sandstone of the 

Frontier dips 8°-20° N. At Kirby Creek the Cody shale dips 6° N., 

and 3 or 4 miles farther north, at the base of the Mesaverde sandstone, 

the beds dip as much as 26° N. These dips suggest the presence of 

what is known as 'a "structural terrace," which in some of the eastern 

fields would be considered favorable for the accumulation of oil and 

gas; in Wyoming, however, such structural features have not been 

tested by the drill and are not known to contain oil and gas in commercial quantities.

In the writer's opinion Plate XVIII, B, which suggests the northwestward prolongation of the known anticline, represents the structure more accurately than Plate XVIII, A. The principal reason for 

so thinking is that the crest line of the anticline parallels the northwest-southeast trend of the anticlines along the south flank of the 

Big Horn Basin. Attention is called to the fact that still other 

interpretations of the structure in this locality may be made.
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XVIII

R.93 W. o

c

Structure contours (lines of equal altitude) on top of Greybull sand. Numbers

show altitude above or depth below sea level. Solid lines represent accurate con- 

- tours; broken lines, hypothetical contours. Interval, 200 feet

STRUCTURE CONTOUR MAPS A AND B, SHOWING TWO INTERPRETATIONS OF

. ZIMMERMAN BUTTE ANTICLINE (No. 25 ON PLATE I) 

Map A shows a possible structural terrace in the western half of the area, and 

map B shows a possible anticline at the same locality 

By Charles T. Lupton
RED SPBING ANTICLINE. 133

The surface rocks of this area belong to the Cody shale, which in 

this locality is about 3,000 feet thick. The rocks beneath the Cody 

shale down to and including the Cloverly formation, on the top of 

which the structure contours are drawn, are the Frontier formation, 

about 600 feet thick; the Mowry shale, about 200 feet thick; the 

Thermopolis shale, about 400 feet thick; and the Cloverly formation, 

about 125 feet thick. The Frontier formation, which consists mainly 

of sandstones interbedded with thin layers of sandy shale and shale, 

is the formation in which oil and gas occur in the Grass Creek, Elk 

Basin, Byron, and Little Buffalo Basin fields. The Mowry shale is 

a dark-gray, slaty, hard shale, about 200 feet thick, with two or more 

sandy beds, which in the Torchlight dome carry oil and gas. Under 

the Mowry is the Thennopolis shale, about 400 feet thick, which 

contains a rather persistent bed of sandstone (Muddy sand) near its 

middle. The top sand of the Cloverly formation the Greybull 

sand is about 20 feet thick and yields all the oil and gas in the 

Greybull field. Underlying the Greybull sand there is about 80 

feet of variegated sandy shale-and shale, mainly red in color, and 

underlying them is a conglomerate sandstone in places about 25 feet 

thick.

CONCLUSIONS.

No drilling has been done in the locality. Although dips do not 

positively show the presence of an anticline in the area west of Zimmerman Butte (a northwest projection of the Zimmerman Butte 

anticline), the probability is strong that one exists and that it may 

serve as a reservoir for oil and gas. If no well-defined anticline or 

dome is present there is without question a lowering of the dips or 

flattening of the beds, which constitutes a structural terrace that in 

some localities is favorable for the accumulation of oil and gas. 

Hence the writer recommends that the small anticline, shown on 

both maps of Plate XVIII, near the southeast corner of the township, 

the S. | sec. 21, the N. £ sec. 28, T. 44 N., R. 93 W., and parts of the 

adjacent sections along its crest projected to the northwest are 

territory worthy of careful investigation by the driller.

RED SPUING ANTICLINE.

By CHARLES T. LUPTON.

GENERAL FEATURES.

The Red Spring anticline (No. 26, PL I), in the southern part of 

the Big Horn Basin in the southwestern part of T. 43 N., R. 93 W., 

has not been tested for oil and gas, but a small seep of heavy oil in. 

the NW. | sec. 29 of the same township suggests that in places it 

contains small amounts of that material. As the lowest bed of rock
134 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

known to carry oil at any place in Wyoming is exposed in the middle 

of the anticline, it is exceedingly doubtful if oil or gas will ever be 

found in commercial quantities.

The anticline is most easily accessible from Thermopolis, on the 

southwest, or from Lucerne, on the northwest, both on the Chicago, 

Burlington & Quincy Railroad. In a direct line it is about 7 miles 

distant from each, but by road it is several miles nearer to Thermopolis, from which a good wagon road, following Big Horn River 

and Kirby Creek, connects about 6 miles east of the Big Horn with 

a second-class road leading south about 5 miles to the heart of the 

west end of the anticline.

The surface of the anticline is characterized by a basin-like depression surrounded by an inward-facing wall of sandstone and shale, in 

places 300 to 400 feet high. (See PI. XIX.) On the north flank of 

the anticline other walls of similar material, less conspicuous, however, 

lie farther out and form a series of corrugations as far as 2 miles from 

the crest line; on the south flank the walls are less prominent and 

occupy a narrower belt. The streams have cut deep canyons, which 

form easy routes into the basin.

Water is scarce near the Red Spring anticline. The entire supply 

comes from a few alkaline and gypsiferous springs of small flow that 

issue mainly from the north flank of the upfold. The best water 

comes from the outermost walls of sandstone. Water for ranch and 

domestic uses and for drilling during the dry months could be caught 

during the flood season and stored in reservoirs.

STRUCTURE.

The Red Spring anticline is an unsymmetrical curved upfold about 

4 miles long, concave to the northeast. (See PI. XIX.) On the south 

limb the dips average about 45° and range from zero at the crest 

trace to as much as 60° locally half a mile to the south, in the NE. \ 

sec. 33, T. 43 N., R. 93 W. On the north limb they are much less 

steep, reaching a maximum of 30° at a point somewhat less than a 

mile from the crest line in the NE. 1 sec. 28, T. 43 N., R. 93 W., and 

thence decreasing northward to about 6° near Kirby Creek. The 

south limb of the anticline dips more steeply than the north and is 

therefore much narrower. The dips are less at the ends of the 

anticline than on the north and south limbs. The structure contours 

drawn on the top of the Greybull sand show the shape of the upfold.

One fault southeast of the crest line of the anticline (see PL XVI, B, 

p. 124) has a downthrow of about 150 feet on the south side. It is 

about 1£ miles long, lying nearly parallel to and not more than onefourth mile from the crest line at any place.

The lowest rocks exposed in the anticline are beds of limestone that 

belong to the Embar formation, the upper part of which is charac-
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XIX

Structure contours (lines of equal altitude) On 

top of Greybull sand. Numbers show distance x 

above sea level. Solid lines indicate preseni. / '' 

position of sand below, and broken lines former 

position above present aurface. Interval, 2OO feet

BLUE SPfclNG 

'

STRUCTURE CONTOUR MAP OF WILDHORSE BUTTE, BLUE SPRING, AND RED SPRING ANTICLINES (Nos. 23, 24, AND 26, RESPECTIVELY, ON PLATE I)

AND TWO CROSS SECTIONS ° 

The outcrops of sands are mapped as sandstones

Note. The crest line of the Red Spring anticline on the surface does not conform to the structure contours in the 

central part of the anticline, because the axial plane is not vertical, and as shown on cross section A-B the 

crest trace of the Greybull sand if restored would lie farther to the southwest.

By Charles T. Lupton
THERMOPOLIS ANTICLINE. 135

terized by a bed of fairly pure gypsum. Directly overlying the 

Embar is the Chugwater formation, about 900 feet thick, which 

contains red sandstone and sandy shale with a thick bed of gypsum 

near the top. The seep of heavy oil in the NW. J sec. 29, T. 43 N.,' 

K. 93 W., is near the base of this formation.

The surface rocks in the center of the Red Spring anticline are 

limestone beds of the Embar formation. Underlying these beds, 

which are about 100 feet thick, are beds of variegated sandstone, 

shale, and limestone of the Tensleep and Amsden formations, 300 or 

400 feet thick. Directly underlying the Amsden formation is a bed 

of massive limestone (Madison), 900 to 1,000 feet thick, the upper 

part of which may contain oil if it is not too dense, as it is overlain in 

most places by an impervious bed of shale which would serve as a 

cap and would prevent the escape of any oil or gas caught under it. 

Underlying the Madison limestone there is 900 to 1,800 feet of limestone, shale, sandstone, and conglomerate, at the base of which the 

granite is exposed in the Big Horn Mountains.

CONCLUSIONS.

It is doubtful if this anticline contains oil and gas, for the lowest 

rocks (Embar formation) exposed in the upfold are the lowest rocks 

that are known to contain oil in the Rocky Mountain region, and any 

oil that may have been contained in them has had opportunity to 

escape.

The possibility of obtaining oil from the upper part of the Madison 

limestone, which lies 500 or 600 feet below the surface in the heart 

of the Red Spring anticline, is also questionable, as oil in commercial 

quantities is not known to occur in this formation in any part of the 

region. The presence of the seep in the NW. J sec. 29, T. 43 N., R. 

93 W., may mean that whatever oil had collected under this anticline has reached the surface, or it may mean that some bed farther 

down the flank of the anticline has caught and held oil because of a 

decrease in the dips.

The writer would not advise the expenditure of much money in 

testing the Red Spring anticline, as it is very doubtful from the obtainable data that it offers a reservoir for oil or gas in commercial 

quantities.

THERMOPOLIS ANTICLINE.

By CHAELES T. LTJPTON.

The Thermopolis anticline (No. 27, PI. I) lies in the southern part 

of the Big Horn Basin and is cut near its center by Big Horn 

River. It was not examined in detail and hence is not separately 

mapped in this report. (See, however, PI. XXI, p. 146.) The town
136 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

of Thermopolis and the hot springs (now included in a State reservation) are situated on its south flank, where the beds dip more steeply 

than they do on its north flank.

The anticline is about 25 miles long and is narrower east of the 

river, where it trends nerly east and west, than it is west of that 

stream, where it trends more nearly northwest and southeast.

The lowest rocks exposed in the crest of the anticline belong to the 

Embar formation, so that the lowest rocks known to carry oil in 

commercial quantities in Wyoming or adjacent States are exposed. 

This condition alone suggests that this anticline contains no oil or gas.

One well (No. 6, PI. XXI) was drilled a few years ago near the 

crest in the NW. 1 sec. 32, T. 43 N., R. 94 W. Little information 

regarding it is available. It was begun in the Chugwater, formation 

and may have penetrated the Embar but found no oil hi commercial 

quantity.

In the writer's opinion the Thermopolis. anticline is of doubtful 

value as a reservoir for oil and gas. This judgment is based on the fact 

that the Embar, the lowest known oil-bearing formation in Wyoming, 

is exposed at the surface west of Big Horn River at the crest of the 

anticline, and also on the fact that the crest of the anticline is faulted. 

This fault is not sealed everywhere, for it permits the water of the 

hot springs to reach the surface. Any oil formerly contained in the 

rocks cut by the fault has had the same means of escape.

LUCERNE ANTICLINE (INCLUDING THE GEBO DOME).

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Lucerne anticline (No. 28, PI. I) is situated mainly in the valley of Big Horn River in T. 43 N., R. 94 W., and T. 44 N., Rs. 94 

and 95 W. A small part of the anticline lies east of Big Horn River 

and the remainder west of that stream near the towns of Lucerne 

and Gebo. Only the northwest part of this anticline, locally called 

the Gebo dome, is believed to contain oil or gas in commercial 

amounts.

The Lucerne anticline may be very easily reached from Lucerne, on 

the Chicago, Burlington & Quincy Railroad. The entire upfold 

can be examined with ease, as the surface of the greater part of it 

is smooth or rolling and good roads are plentiful.

The surface features near the anticline are the broad valley of Big 

Horn River, where the bedrock is covered by a veneer of alluvium and 

terrace gravel, and the more hilly southeast and northwest ends, 

where the bedrock is well exposed. The surface elevations vary 

from about 4,300 feet near Big Horn River to 5,200 feet in the northeast corner of sec. 12, T. 44 N., R. 96 W.
LUCERNE ANTICLINE. 137

The principal water supply of this locality is from Big Horn River. 

During the spring months and after rainstorms, water flows in the 

intermittent streams shown on Plate XXI (p. 146), but it is not found 

throughout the year except locally in small springs. Owl Creek 

carries water for the greater part of the year, but during the summer months most of its water is appropriated for irrigation. Hence 

water for drilling and for camp and ranch purposes must be obtained 

from Big Horn River, or from reservoirs built near the stream courses 

to catch and hold the flood waters, or from shallow wells in the 

alluvium and gravel near Big Horn River.

STRUCTURE.

The Lucerne anticline is a broad northwestward-plunging wrinkle 

in the rocks on the south rim of the Big Horn Basin. (See PL XXI.) 

A sag in the anticline near Lucerne makes the northwest half of the 

upfold, the Gebo dome, apparently a good reservoir for oil and gas. 

The anticline is about 13 miles long, and, like most of the anticlines 

along the south side of the Big Horn Basin, has steep dips on the 

southwest and more gentle dips on the northeast, and consequently 

has a narrow south limb and a broad north limb. The dip on the 

south linab increases from zero at the crest line to 35° in the northeast 

corner of sec. 21, T. 44 N., R. 95 W., beyond which it gradually decreases toward the trough of a syncline which lies one-fourth to 

three-fourths of a mile southwest of the crest line of the anticline. 

The dip on the north limb ranges from zero near the crest line to as 

much as 32° at a point ! £ miles to the northeast, about half a mile 

north of the coal-mining camp of Gebo, beyond which for about 9 miles 

it gradually decreases, reaching zero at the axis of the syncline just 

south of the Neiber anticline. The dips at the northwest and southeast ends of the anticline are very gentle. Exposures are poor 

directly west and northwest of Lucerne, and it is impossible to state 

with certainty whether or not the upfold mapped as the Lucerne 

anticline is continuous. Dips measured in sees. 23-26, T. 44 N., 

R. 95 W., show definitely that there is a shallow saddle or depression 

(which cuts off the Gebo dome) along the crest of the anticline. At 

the northwest end, near the southeast corner of sec. 8, T. 44 N., 

R. 95 W., the strata dip perceptibly to the northwest. The dips at 

the southeast end of the Gebo dome range from 2° to 7° in sees. 25 

and 26, T. 44 N., R. 95 W.

The structure contours are drawn on the top of the Greybull sand 

at intervals of 200 feet.- These* contours show the general shape and 

size of the anticline and its relation to the Sand Draw anticline which 

lies to the northwest. From these and from the surface elevations 

(p. 136) the depths to the Greybull and other sands may be determined. (See p. 39.)
138 ANTICLINES IN SOUTHERN PART OP BIO HORN BASIN, WYO.

The lowest surface rocks exposed hi the Lucerne anticline belong 

to the Morrison formation, which is exposed only at the southeast 

end of the anticline in sees. 16 and 22, T. 43 N., R. 94 W. It consists of variegated sandstone and shale and is about 300 feet thick. 

Overlying it is the Cleverly formation, about 125 feet thick, with a 

gray to white conglomeratic sandstone bed at its base overlain by 

variegated sandy shale, which in turn is overlain by a sandstone bed 

(the Greybull sand) about 20 feet thick that is known to carry oil' 

and gas in the Greybull field. The Cloverly formation is-overlain by 

the dark and in places fossiliferous Thermopolis shale, in this locality 

about 400 feet thick, which has near its middle a persistent bed of 

sandstone (Muddy sand), which, however, is not known to carry oil 

or gas in this general region except in the Oregon Basin. The Thermopolis shale is overlain by the Mowry shale, about 250 feet thick, 

which consists of hard, dark-gray, platy shale, with one or two beds 

of sandstone and a few thin beds of bentonite. This formation 

carries the oil and gas found in the Torchlight dome, near Basin. 

Overlying the Mowry is the Frontier formation, about 600 feet thick, 

which contains several beds of sandstone and minor quantities of 

shale and sandy shale. This formation carries the oil and gas in 

the Grass Creek, Little Buffalo Basin, and Elk Basin fields. The 

Frontier formation is overlain by the Cody shale, about 3,000 feet 

thick in this part of the basin, which contains thin beds of fossiliferous 

sandstone near the top and one or two very thin beds of sandstone 

near the base. The Cody forms the surface rock of the greater part 

of the Gebo dome at the northwest end of the Lucerne anticline. 

It is overlain by the Mesaverde formation, which is mainly sandstone and sandy shale, with beds of coal near its base.

DEVELOPMENT.

The anticline is untested with the exception of a well (No. 5, 

PL XXI) drilled about 2,500 feet deep by the Ohio Oil Co. in the 

NE. | NW. i sec. 16, T. 44 N., K. 95 W., about 1J miles west of Gebo. 

This well is reported to have penetrated the upper sands of the 

Frontier formation at a depth of about 2,000 feet and to have failed 

to find oil or gas of economic importance. The well is near the crest 

line of the anticline but is not at the highest part of the Gebo dome, 

which is about 2 mites farther southeast. The entire area of the 

anticline is withdrawn from entry by the Government, and it is 

doubtful if it will be thoroughly tested until a law has been passed 

by Congress enabling the various companies to lease the land on which 

to drill.
NEIBER ANTICLINE. 139 

CONCLUSIONS.

Only the part of the Lucerne anticline included in what is known 

as the Gebo dome is believed to contain oil or gas. This judgment is 

based on the fact that the anticline plunges from its southeast end 

to a point a mile or more northwest of Lucerne, or to the saddle 

separating the southeast end of the anticline from the Gebo dome. 

Any oil or gas contained in this southeast half of the anticline has 

had an easy means of escape through.the sandstone beds to the 

surface, where beds as old as the upper part of the Morrison formation outcrop. If another hole is drilled on the Gebo dome, the writer 

advises that the best location appears to be near the crest line of the 

dome near Coal Draw in the W. * sec. 23, T. 44 N., R. 95 W. This 

dome is ideally situated for drilling, as fuel is plentiful at the Gebo 

coal mines near by, and water occurs in seeps along Coal Draw and 

may be stored in reservoirs along the intermittent streams near the 

southeast end of the dome.

NEIBER ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Neiber anticline (No. 29, PI. I) in the southern part of the Big 

Horn Basin has its greatest development on the east side of Big Horn 

River (PI. XX) but crosses that stream about a mile above the mouth 

of Gooseberry Creek and extends westward for 6 to 7 miles. This 

anticline is one of those folds nearest the deeper part of the Big Horn 

Basin and should, if other conditions are favorable, carry oil and gas 

in commercial quantities. The sands which contain oil and gas in 

the Grass Creek, Little Buffalo Basin, Torchlight, Greybull, and 

Byron fields are too deeply buried, 7,500 feet or more below the surface, in the Neiber anticline to be reached by the average drilling rig, 

but other sands lie within 3,QOO or 3,500 feet of the surface and may 

contain oil or gas. None of them, however, were penetrated by the 

only well drilled, although a little gas was reported from several 

horizons.

This anticline is easily accessible, as it is crossed near its middle by 

the Chicago, Burlington & Quincy Railroad and also by a good wagon 

and automobile road connecting Worland and Thermopolis. Much 

of the part lying west of the river can be traversed with wagon or 

automobile, but the part east of the river can be examined in detail 

only on foot or horseback, as the surface, especially within 3 miles of 

the river, is very rough. Neiber, a post office about 2 miles north of 

the axis of the anticline, is the nearest railroad station at which all 

passenger trains stop. Hotel and livery accommodations are much
140 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

better at Worland, about 10 miles farther northeast, or at Kirby, an 

equal distance to the southwest, than they are at Neiber.

As this anticline is crossed by the broad valley of Big Horn River, 

which in places is more than 2 miles wide, the surface in the middle 

part is relatively smooth. West of the river flood plain the surface 

consists in part of the remnants of gravel-capped terraces, cut by 

intermittent streams which flow parallel to the crest line of the fold; 

near the heads of some of these streams badlands are developed. 

Immediately east of the river the surface is exceedingly rough, for it 

is sharply dissected by numerous streams, but at the east end it is 

much smoother than that just described and more nearly resembles 

the country lying west of the river.

The main water supply is derived from Big Horn River, which carries an almost inexhaustible quantity of excellent water throughout 

the year. Gooseberry Creek, a, few miles north of the anticline, and 

Meeyero Creek, an equal distance south, also contain water along 

their courses or in pools throughout the greater part of the year but 

are usually considered intermittent streams. The intermittent 

streams cany water only in spring, early in summer, and after 

heavy rainstorms. No perennial streams except Big Horn River 

are known at any place near the anticline. Reservoirs in which flood 

waters could be impounded could be made with little difficulty at 

many places, particularly along the courses of some of the intermittent streams.

STRUCTURE.

The Neiber anticline is an. unsymmetrical upfold about 15 miles 

long trending northwest. The north limb is much broader than the 

south and constitutes an extensive gathering ground for any oil or 

gas that may have originated in the deeper parts of the Bighorn 

Basin. The dips on the narrow south limb are much steeper than 

those on the north limb. They range from zero at the crest line to as 

much as 21° near the trough of the syncline in sec. 21, T. 45 N., R. 

93 W. The maximum dip on the north limb is believed to be 8°, 

which was noted near the northeast comer of sec. 9, T. 45 N., R. 

93 W., about a mile northeast of the crest line. From here the dip 

gradually decreases to the central part of the Big Horn Basin. Other 

dips show that the anticline pitches slightly at each end.

The lowest surface rocks belong to what is thought to be the lower 

part of the Fort Union formation. The total thickness of the formation, which consists mainly of sandstone interbedded with sandy shale 

and clay, has not been determined in this locality, but is believed to 

be about 1,500 feet. Unconformably overlying the Fort Union is the 

Wasatch formation, which is largely variegated sandstone, clay, and 

shale, and here and there beds of conglomerate, and which outcrops 

along the synclinal axis east of Big Horn River.
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XX

Structure contours (lines of ecjual altitude) on -top of Greybull sand. Numbers 

show depth below sea level. Contour interval, 2OO feet

\

STRUCTURE CONTOUR MAP OF NEIBER ANTICLINE (No. 29 ON PLATE I)

By Charles T. Lupton
NEIBER .ANTICLINE. 141

The rocks through which the drill will pass on the'crest of the anticline near Big Horn River consist-first of 800 feet or more of the 

lower part of the Fort Union formation. Directly underlying these 

is the Lance formation, about 1,800 feet thick, which is similar to 

the overlying Fort Union and consists of yellowish-gray sandstone 

interbedded with shale. Underlying the Lance is the Meeteetse 

formation, about 350 feet thick, which is believed to correspond to 

the Lewis shale of southern Wyoming and to the Bearpaw shale of 

central Montana. Below the Meeteetse is the Mesaverde formation, 

about 1,200 feet thick, consisting of massive sandstone and sandy 

shale with coal beds near the base which are mined at Gebo and 

Crosby on the west side of Big Horn River, a few miles southwest of 

Kirby. The top sandstone of this formation, being overlain by the 

impervious Meeteetse shale, may possibly contain oil. Directly 

underlying the Mesaverde is the Cody shale, about 3,000 feet thick, 

and underlying it is the Frontier and other formations.

The structure contours drawn on the top of the Greybull sand, or 

top sandstone of the Cloverly formation, in which the oil and gas are 

found in the Greybull field, together with the surface elevations, 

which range from about 4,100 feet near the center of sec. 1, T. 45 N., 

R. 94 W., to about 4,700 feet near the center of sec. 16, T. 45 N., 

R. 93 W., enable the depth from the surface to the Greybull sand or 

to any other sand whose position with relation to the Greybull is 

known to be determined. (See p. 39.)

DEVELOPMENT.

A well (PI. XX), drilled with a standard rig in the NE. £ NW. J 

sec. 3, T. 45 N., R. 94 W., by the Tanberg OH Co., of Thermopolis, 

Wyo., was begun in May or June, 1915, and by the last of July 

had reached a depth of about 900 feet. A little gas is reported to 

have been encountered at a depth of about 600 feet. Drilling was 

continued to about 2,000 feet, but according to the latest reports no 

oil or gas had been obtained in commercial quantities. Much water 

was encountered at a depth of about 1,000 feet. The mouth of the 

well is about 4,340 feet above sea level. A generalized log of this well 

follows:

Log of well drilled in the NE. J NW. J sec. 3, T. 45 N., R. 94 W., near Neiber, Wyo.

Hard shells, brown sandstone, hard white sandstone, and black shale. (Bottom of 

hole, Mar. 23, 1916) ............... ...............................................

Thickness.

Feet. 

750

250

150

750

mn

Depth.

Feet. 

750

1,000

1,150

1,900

2,000
142 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

CONCLUSIONS.

As the sands of the Frontier formation, which carry oil and gas in 

the Grass Creek and Little Buffalo basins, are 7,500 to 8,000 feet 

below the surface at the point where the crest line of the Neiber 

anticline crosses Big Horn River, they must be eliminated from the list 

of possible oil sands at present available. The next higher sand of 

possible value is at the base of the Mesaverde formation, 4,200 to 

4,700 feet below the surface; and its value is questionable, for it 

is not covered by an impervious cap of shale, a necessary condition 

for the retention of oil or gas in areas where the sands are saturated 

with water, as they are in places in the Big Horn Basin. Near the 

top of the Mesaverde, about 1,200 feet above the base, a sand of 

suitable texture and density is overlain by a bed of shale (Meeteetse) 

about 350 feet thick, which serves as an impervious cap. This sand 

lies at a depth of probably not more than 3,000 feet. If it does 

not contain oil or gas in commercial quantities, it is doubtful if the 

underlying sandstone beds of the Mesaverde are sufficiently promising 

to warrant further drilling«.operations. The writer therefore advises 

against deeper drilling until such a time as drilling rigs are perfected to 

penetrate a depth of 7,000 or 8,000 feet without difficulty. At that 

time the sands of the Frontier formation may here be found to carry 

oil and gas.

The well in the NE. £ NW. J sec. 3, T. 45 N., R. 94 W. (PI. XX), 

is f airly well located to test the western half of the anticline but was 

not drilled deep enough to penetrate the top sandstone of the Mesaverde formation, which lies 1,000 or 1,200 feet deeper.

If the eastern part of the anticline is tested the writer advises 

drilling 800 to 1,200 feet north of the crest, approximately in the 

SW. 1 NW. i sec. 15, T. 45 N., R. 93 W., where the top sandstone 

of the Mesaverde can be penetrated at a depth of about 3,500 feet.

SAND DRAW ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Sand Draw anticline (No. 30, PI. I), an untested small upfold 

on the north flank of the larger Thermopolis anticline, is situated 

mainly in the southern part of T. 45 N., R. 96 W., about 10 miles 

west of Kirby and 16 miles northwest of Thermopolis. It lies mainly 

in the drainage basin of Sand Draw, which joins Big Horn River near 

Kirby.

This anticline is most easily reached from Kirby, a town on the 

Chicago, Burlington & Quincy Railroad directly west of Big Horn 

River. From this place a good road, over which much of the freight
SAND DEAW ANTICLINE. 143

to the Grass Creek oil field has been hauled, follows in general the 

course of Sand Draw and crosses the northwest end of the anticline. 

Parts of the anticline, however, can be reached only on foot or on 

horseback.

The surface of the anticline is characterized by the valley of Sand 

Draw, which crosses the anticline transversely and in places is narrow 

and canyon-like.

The surface is rough and hilly near the tributaries of Sand Draw. 

The altitude of the surface ranges from about 4,840 feet in the NE. J 

sec. 20, T. 45 N., R. 96 W., to about 5,225 feet in the SW. J sec. 34 

of the same township.

The water supply near the anticline is meager and obtained wholly 

from Cottonwood and Grass creeks and Sand Draw, all of which 

are intermittent streams that carry water only in spring, early in 

summer, and after rainstorms, and from a few alkaline springs along 

these streams which supply small quantities of water in the dry season. 

A little water for camp use can be obtained from the Zimmerman 

spring, on the Thermopolis-Grass Creek road in sec. 23, T. 44 N., R. 

96 W., about 3 miles south of the southeast end of the anticline.

STRUCTURE.

The Sand Draw anticline is a northwestward-pitching unsymmetrical upfold about 4£ miles long with its narrow flank on the southwest side. The comparative narrowness of the southwest limb is 

due mainly to the greater steepness of its dip, which ranges from 

nearly zero at the crest line to as much as 18° near the center of 

sec. 33, T. 45 N., R. 96 W. On the northeast limb the dip reaches 

a maximum of 14° at a point about a mile from the axis, beyond 

which it gradually decreases to zero in the synclinal trough south of 

Neiber anticline. The dip at the southeast end of the anticline is 

slight. One dip of 4° S. in the northern part of sec. 11, T. 44 N., R. 96 

W., suggests that the anticline pitches slightly at its southeast end.

The lowest surface rocks belong to the upper part of the Cocly 

shale, about 2,800 feet thick, which is exposed at the extreme southeast end of the upfold at the reentrant in the cliff line in sees. 1, 2, 

and 3, T. 44 N., R. 96 W. (See PL XXI, p. 146.) Overlying the 

Cody shale is the Mesaverde formation, about 1,200 feet thick, consisting mainly of sandstone with minor amounts of sandy shale, 

shale, and coal beds (mined at Gebo and Crosby, a few miles to the 

east). Resting on the Mesaverde formation is the Meeteetse formation, about 350 feet thick and largely shale. Above the Meeteetse lies 

a mass of sandstone and shale, sandstone predominating, about 3,000 

feet thick, which includes the Lance and Fort Union formations. 

Probably little more than half of these formations lies beneath the 

surface at the northwest end of the anticline near Cottonwood Creek.
144 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

The rocks directly beneath the surface at the southeast end of the 

anticline belong to the Cody shale. A deep well here would-pass 

through about 2,000 feet of this shale before reaching the underlying sandstone beds (of the Frontier formation) that carry oil and 

gas in the Grass Creek and Little Buffalo Basin fields. This predominantly sandy formation is about 600 feet thick and contains thin 

layers of sandy shale, shale, and bentonite. Below the Frontier is 

the Mowry, a hard, gray, platy shale 200 to 300 feet thick, which 

contains one or more sandstone beds that carry oil and gas in the 

Torchlight dome, near Basin. Underlying the Mowry is the darkgray Thermopolis shale, about 400 feet thick, containing near its 

middle in most places a bed of sandstone (the Muddy sand), which 

is not known to contain oil or gas hi the Big Horn Basin except in the 

Oregon Basin. Underlying the Thermopolis shale is the Cloverly 

formation, about 125 feet thick, which consists of an upper sandstone 

(the Greybull sand, which carries oil and gas in the Greybull field) 

about 20 feet thick, a middle variegated shale about 80 feet thick, 

and a lower conglomeratic sandstone about 25 feet thick.

The structure contours drawn on the top of the Greybull sand 

and the cross section (see PI. XXI, p. 146) show the shape and size 

of the anticline. With these contours and surface elevations known, 

the approximate depth of the Greybull sand may be determined. 

(See p. 39.)

CONCLUSIONS.

The Sand Draw anticline has not been drilled, and no seeps of oil 

or vents of gas on it are known. The part of the anticline that 

should be first prospected is the domelike expansion at the southeast 

end, where the Frontier formation can be reached with the least 

drilling; sees. 2 and 11, T. 44 N., R. 96 W., are recommended. The 

top of the Frontier formation, the oil and gas bearer in the Grass 

Creek and Little Buffalo Basin fields, is about 2,000 feet beneath the 

surface; and the Greybull sand, the oil and gas bearer in the Greybull field, is about 1,200 feet deeper.

WAUGH ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The Waugh anticline (No. 31, PI. I) is in T. 44 N., Rs. 90 and 97 W., 

and T. 45 N., R. 97 W., about 25 miles northwest of Thermopolis 

and about an equal distance west of Kirby, both on the Chicago, 

Burlington & Quincy Railroad. It can be most easily reached from 

Thermopolis along the well-traveled road leading to the Grass Creek
WAUGH ANTICLINE. 145

oil field, which lies 15 miles farther northwest. This main road lies 

within 1J miles north of the crest line of the Waugh anticline at 

almost every point. As the surface is comparatively smooth, many 

second-class roads lead from the main road, making nearly all parts 

of the anticline easily accessible.

The area adjacent to this anticline is for the most part smooth, but 

its west end is trenched by the valley of Cottonwood Creek and here 

and there at other places by shallow valleys. On its southwest side 

prominent cliffs of sandstone show interbedded shale and one or more 

beds of coal. These cliffs are rugged, but the possible oil-bearing 

part of the anticline lies in the smooth lower country nearer the crest.

The water supply is derived from Cottonwood Creek, which is intermittent except for small flows of water from seeps that occur here 

and there along its course. Reservoirs to catch and hold the flood 

waters along the beds of the intermittent streams can be easily made 

in the soft impervious shale which forms the surface rock of the 

greater part of the anticline.

STRUCTURE.

The Waugh anticline is a northwestward-pitching wrinkle on the 

north flank of the larger Thermopolis anticline, which is about 25 

miles long and in places is 10 miles wide. The Waugh anticline is 

unsymmetrical, the southwest limb being narrower than the northeast. (See PL XXI.) The dips on the southwest limb attain a 

maximum of 53° in the NW. i NW. \ sec. 3, T. 44 N., R. 97 W., and. 

those on the northeast limb a maximum of 24° near the center of 

sec. 35, T. 45 N., R. 97 W., about one-fourth of a mile from the crest 

line. From here northeastward the dips decrease gradually to the 

trough of the syncline, which parallels the anticline about 4 miles 

northeast. The beds at the northwest end of the anticline dip as 

much as 10° NW., indicating that the anticline pitches sharply. At 

the southeast end the beds in the lower part of the Cody shale dip 

slightly southeast, suggesting that the anticline pitches in that direction for a short distance, but this slight dip probably has not affected 

the underlying sandstone beds (Frontier formation) which carry oil 

in some parts of the Big Horn Basin. If it has not, the anticline 

is not promising as an oil or gas reservoir, for any oil that may have 

accumulated along the crest would have a free avenue of escape 

toward the southeast.

The surface rocks of the Waugh anticline belong to the lower part 

of the dark-gray Cody shale, which is about 2,500 feet thick and contains thin sandstone beds near its top and base.

Beneath the surface are the lower part of the Cody shale, Frontier 

formation, consisting mainly of sandstone with thin layers of shale 

§6133° Bull, 650 17 10
146 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

and bentonite about 500 to 600 feet thick; the Mowry shale, about 175 

feet thick; the Thermopolis shale, about 400 feet thick, and other 

formations. The Frontier formation is the most important, as it carries the oil and gas found hi the Grass Creek and Little Buffalo fields, 

10 and 25 miles, respectively, to the northwest.

Four wells have been drilled on this anticline, but only two of 

them have reached the Frontier formation. The log of the Levi 

No. 3 well (No. 3, PI. XXI) is given to show the character and thickness of the beds down to and including the upper part of the Frontier 

formation.

. Log of Levi No. 3 well, in the NE. \ NE. \ sec. i, T. 44 N. t R. 97 W.

Shale...... .........................................................................

Shale, tough ........................................................................

Shale...............................................................................

Shale...............................................................................

Sand (showing trace of oil) ..........................................................

Slate................................................................................

Sand................................................................................

Thickness.

Feet. 

1,370

12

45

60

8

7ft

130

35

4

2

10

17

7

Depth.

Feet. 

1,370

1,382

1,427

1.487

1,495

1,525

1,655

1.690

1.694

1,696

1,706

1,723

1,730

This well was drilled by Levi & Son from February to May, 1915. 

The surface elevation of its mouth is about 5,050 feet.

The structure contours drawn on the top of the Greybull sand, 

supplemented by the cross section (see PL XXI), show the shape and 

extent of the anticline. With these and the surface elevations, 

which range from about 4,900 feet above sea level in the SE. £ sec. 23, 

T. 45 N., R. 97 W., to about 5,400 feet in the NE. \ sec. 3, T. 44 N., 

R. 97 W., the approximate depth to the top of the Greybull sand or 

any other sand whose position with relation to the top of that sand 

is known may be determined.

Faults are not known in any part of the anticline, but they may be 

present and undetected, as it is exceedingly difficult to detect them 

in the Cody shale.

DEVELOPMENT.

Of the four wells drilled by Levi & Son on this anticline the Levi 

No. 1 (No. 1, PI. XXI) in the NE. £ NW. i sec/2, T. 44 N., R. 97 W., 

was drilled (from August to December, 1914)"to a depth of 880 feet, 

all of it in black shale. No trace of oil or gas was found. The elevation of its mouth is about 5,025 feet. The Levi No. 2 (No. 2, PL XXI) 

in the SW. i SE. £ sec. 35, T. 45 N., R. 97 W., was drilled (December, 

1914, to January, 1915) to a depth of only 200 feet in the shale. The
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XXI

Structure contours (lines of equal altitude) on top of Greybull sand. 

Numbers show altitude above or depth below sea level. Solid lines 

indicate position of sand where present, and broken lines former 

position of the sand. Contour interval, 200 feet

STRUCTURE CONTOUR MAP OF THERMOPOLIS, LUCERNE (INCLUDING GEBO DOME), SAND DRAW, AND WAUGH ANTICLINES (Nos. 27, 28, 30, AND 31, RESPECTIVELY, ON PLATE 1) AND TWO STRATIGRAPHIC SECTIONS

The outcrops of sands are mapped as sandstones 

By Charles T. Lupton
COTTONWOOD ANTICLINE. 147

elevation of its mouth is about 5,075 feet. A log and other information regarding the Levi No. 3 well is given above. The Levi No. 4 

well (No. 4, PL XXI) in the NW. i NE. £ sec. 2,.T. 44 N., R. 97 W., 

penetrated to a depth of 1,272 feet. It entered the top of the 

Frontier formation at a depth of 1,035 feet and found, at 1,150 feet, 

an oil sand with a fair showing of oil, below which was water. The 

well was stopped after drilling about 70 feet into the underlying 

shale.

CONCLUSIONS.

As two of the wells described have penetrated the Frontier formation without finding more than showings of oil and gas it seems 

doubtful if this anticline is an important oil and gas reservoir. The 

highest part of the iipfold, in which oil and gas are most likely to be 

found, is about 2 miles southeast of the wells near the point where 

the strata dip slightly to the southeast. Any further drilling should 

be done somewhere near the crest line, preferably in the SW. I sec. 7, 

T. 44 N., R. 96 W. Possibly the change of dips (p. 145) does not 

affect the underlying sandstones, and unless it does it is almost certain that no oil or gas in commercial quantities will be found in the 

Waugh anticline.

COTTONWOOD ANTICLINE.

By D. F. HEWETT. 

GENERAL FEATURES.

The Cottonwood anticline (No. 32, PI. I) crosses the valley of 

Cottonwood Creek about 23 miles northwest of Thermopolis. Its 

highest part is well shown by conspicuous outcrops of sandstone in 

the east half of T. 44 N., R. 98 W., but it extends eastward and 

northward beyond the limits of this township. It has been tested 

near the crest by three wells, but as none has yielded oil or gas the 

anticline is not regarded as favorable for exploration. It may be 

reached from Thermopolis by the road up Owl Creek to Rothwell 

and thence north of Cottonwood Creek; or from Kirby up the Sand 

Draw road to Waugh's ranch and thence southwest along Cottonwood Creek.

The crest of the anticline is marked by a number of concentric 

ridges surrounded by a broad plain that is trenched by a few streams 

and interrupted here and there by low ridges and gravel-covered 

terraces. North of the anticline this plain has a width of about 4 

miles and is bounded by a rugged escarpment, which, in T. 45 N., R. 

98 W., is an almost unbroken and impassable wall 200 to 450 feet 

high.

There are no perennial streams in the vicinity of the anticline. 

Cottonwood Creek, whose course cuts across the anticline, derives.
148 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

its supply from snow fields that lie among the outlying ridges of the 

Shoshone Mountains; but water does not flow on the surface in this 

region between the middle of August and the later part of November 

in years of average rainfall. The flow of Cottonwood Creek near 

Kemp's ranch, in sec. 17, T. 44 N., R. 98 W., early in August, 1913, 

was estimated at 25 gallons a minute. The ranches along the valley 

derive their water supply from wells dug in the wash near the stream. 

Several stream courses, such as that of Wagonhound Creek, contain 

a few pools of highly alkaline water that are used only by stock on 

the near-by range.

In comparison with much of the region on the west side of the 

Big Horn Basin, vegetation is sparsely distributed near the valley 

of Cottonwood Creek and is limited to grasses, sagebrush, and a few 

pines which occur along outcrops of sandstone. Alfalfa and oats 

are grown by irrigation along the lower part of the valley of Cottonwood Creek.

STRUCTURE.

Erosion has cut deeper into the crest of this anticline than into 

most of those on the west side of the Big Horn Basin, and all of the 

sandstone beds of the Frontier formation are well exposed along a 

series of roughly elliptical parallel ridges. Four fairly persistent 

sandstones correspond closely to the beds reported in the wells of 

the Grass Creek Basin. The Frontier sandstones dip 10° NE. on the 

flat limb of the anticline, and the basal Mesaverde sandstone, which 

outcrops nearly 3 miles to the northeast, dips 12° NE. These relations indicate a thickness of 2,950 feet for the Cody shale a formation that is only 1,900 feet thick on the southwest or steep limb of 

the anticline and 2,450 feet in the Grass Creek Basin. It is therefore 

assumed that the beds along the flat north limb (concealed by .the 

valley wash) dip locally less than 10° and that there is a pronounced 

structural terrace on that limb. The form of the escarpment of 

Mesaverde sandstones farther west is also such as would be produced 

by a structural terrace.

In making the structure contours of Cottonwood anticline on the 

Waugh coal bed the thickness of Cody shale has been assumed to be 

2,050 feet, and the distance from the base of the Mesaverde to the 

Waugh coal bed 50 feet. On the flat northeast limb of the anticline 

the contours are therefore about 2,100 feet higher than the top of the 

Torchlight (?) sand. On the steep southwest limb, the difference in 

elevation is slightly greater because the dips are so much greater than 

on the northeast limb.

The beds that would show the form of Cottonwood anticline west 

of the highest sandstone of the Frontier formation are concealed by 

the gravel which covers Wagonhound Bench, and the structure
WAGONHOUND ANTICLINE. 149

contours of the area north of Cottonwood Creek are adjusted, therefore, to the few outcrops on the southeast end of the Wagonhound 

anticline.

On the southwest limb of the Cottonwood anticline, the beds of 

Frontier sandstone attain a maximum dip of 72°, whereas the overlying Mesaverde sandstone dips 44° to an extensive syncline.

The crest of the anticline is broken by a number of nearly vertical 

faults, which offset the beds of Frontier sandstone. The stratigraphic 

displacement of most of these is small and it is scarcely probable that 

they extend far into the overlying Cody shale.

DEVELOPMENT.

When field work was concluded in this region in September, 1913, 

one well near the crest of the anticline, in the NW. J SE. J sec. 14, 

T. 44 N., R. 98 W., had been completed and a new well 100 feet to 

the southeast had reached a depth of 850 feet. In 1916 this well was 

abandoned and a third had been drilled to an unknown depth near 

the southeast corner of sec. 14. The first two wells started in the 

upper part of the Thermopolis shale and passed through the Cleverly 

and Morrison formations into the upper part of the Sundance formation, and it is reported that no oil or gas was found. It is also reported that it was necessary to haul water for drilling purposes 

throughout the period of operations.

CONCLUSIONS.

As all the Frontier sandstones outcrop and as two wells have failed 

to show the presence of water, oil, or gas on the crest of this anticline, 

it is regarded unfavorable territory for further exploration. In view 

of this conclusion, the prospects for oil or gas on a structural terrace 

in the sandstones of the Frontier formation on the north limb of the 

anticline in sees. 34, 35, and 36, T. 45 N., R. 98 W., and sees. 5 and 6, 

T. 44 N., T. 97 W., are not particularly favorable.

WAGONHOUND ANTICLINE.

By D. F. HEWETT. 

GENERAL FEATURES.

Fair exposures of Cody shales in sec. 6, T. 44 N., R. 98 W., show 

the end of a narrow anticline (No. 33, PI. I) which pitches southeast, 

although no exposures under the lowest Mesaverde sandstone have 

been found farther northwest, which indicates closely the position 

of the crest. There is little doubt, however, that there is a welldefined crest which is not continuous with that of the Cottonwood 

anticline farther southeast.

The anticline is exposed in a small basin that contains numerous 

irregular flat-topped ridges which were once continuous with Wagon-
150 ANTICLINES IN SOUTHERN PART OF BIG HO^N BASIN, WTO.

hound Bench, an extensive gravel-covered terrace that lies north of 

Cottonwood Creek. The basin is bounded on the west and north by 

a steep, rugged escarpment of Mesaverde sandstone. Wagonhound 

Creek and its several tributaries, which are dry during the summer and 

fall months, .rise in a rough region that lies west of the escarpment. 

By cleaning out Wagonhound Spring sufficient water was obtained 

to supply boilers and a camp while several wells were being drilled 

on the anticline.

The anticline may be reached by an old road that leads from lower 

Wagonhound Bench to Wagonhound Spring in the northwest corner 

of sec. 36, T. 45 N., K. 99 W., or by a new road that leaves Cottonwood Creek near Kemp's ranch.

During 1915 and 1916 three wells were drilled near the crest of the 

anticline, two of which passed through the productive sandstones of 

the Frontier formation. Only traces of oil and gas were found in these 

wells. It is not thought that the anticline offers an encouraging area 

for the discovery of oil and gas in commercial quantities.

STRUCTURE.

The outcrops of Cody shale on the basis of which structure contours 

are drawn are limited to a small area along a shallow ravine near well 

No. 2, in the S. J sec. 5, T. 44 N., R. 98 W. (See PI. XXII.) These 

outcrops show clearly the east end of a narrow anticline which 

plunges southeast in the general direction of the Cottonwood anticline. 

No outcrops could be found in any of the ravines west and north of 

this well under the sandstone at the base of the Mesaverde formation.

About 1,000 feet northeast of well No- 2 thin sandy layers in the 

dark-gray Cody shale dip 12° NE., whereas the massive beds of Mesaverde sandstone which limit the basin 2 miles north dip 14°. On 

the south limb outcrops of Cody shale dip 18° SW., whereas the 

lowest sandstone of the Mesaverde formation dips from 24° to 36°. 

In order to calculate the thickness of Cody shale, both the observations of dip of the beds and the logs of the wells have been considered. 

These data show that the Cody shale southwest from well No. 2 is 

about 2,300 feet thick and about 2,450 feet near well No. 1. The 

distance from the Waugh coal bed to the base of the Mesaverde formation is 135 feet.

The anticline disappears in a region of complicated structure along 

Prospect Creek, 3 miles northwest of Wagonhound Spring.

DEVELOPMENT.

Three wells have been drilled close to the crest line of the anticline 

No. 1, 1,833 feet; No. 2, 1,300 feet; and No. 3, 680 feet deep. The 

results obtained in drilling these wells are submitted by Mr. C. S. 

Sollars. The log of well No. 1 is given herewith.
U. S. GEOLOGICAL SURVEY

R.99 W. R.98 W.

BULLETIN 656 PLATE XXII

R.97 W.

Structure contours 

(lines of equal altitude) 

on top of Waugn coal bed. 

Numbers show altitude 

above sea level. 

Solid lines indicate position of bed where present, ' 

and broken lines, former ' 

coal bed. I

Contour inberval 200 feet ,

Dry hole

STRUCTURE CONTOUR MAP OF COTTONWOOD AND WAGONHOUND ANTICLINES (Nos. 32 AND 33 ON PLATE I)

AND ONE CROSS SECTION

The outcrops of sands are mapped as sandstones

By D. F. Hewett

o

Scale 62,5oo 2
GRASS CEEEK ANTICLINE. 151

Log of well No. 1, Wagonhound anticline, NE. \ sec. 36, T. 45 N., R. 99 W.

Cody shale:

Frontier formation: 

Sandstone, dark. ................................................................

Shale............................................................................

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

Sandstone with shale. ...........................................................

Sandstone, gray; water.. . .......................................................

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

Shale, with bentonite. ..........................................................

Sandstone, oil. ..................................................................

Thickness.

Feet. 

1,505

23

18

60

64

20

35

5

24

5

16

12

8

7

12

7

2

10

Depth.

Feet. 

1,505

1,528

1,546

1,606

1,670

1,690

1,725

1,730

1 754

1,759

1,775

1,787

1 795

l'802

1 814

1 821

1,823

1,833

It is reported that the flow of water from this well was temporarily 

too great to determine the amount of oil that could be produced 

Well No. 2, in the S. £ sec. 6, T. 44 N., R. 98 W., struck a sandstone 

with a show of oil at 475 feet and was continued to 1,300 feet but 

did not strike appreciable quantities of oil or gas in deeper sands. 

As the uppermost bed of sandstone was reported to be underlain by 

320 feet of shale, it may not be the top of the Frontier, for both along 

the Cottonwood anticline, 5 miles southeast, and the Grass Creek 

anticline, 10 miles north, this zone of the Frontier contains several 

beds of sandstone. Well No. 3 was drilled to 680 feet without striking 

any beds of sandstone.

CONCLUSIONS.

Wells Nos. 2 and 3 are well placed to test the highest part of the 

anticline, but the first yielded traces of oil only, and the second has 

not penetrated the sands of the Frontier formation. The records 

of wells Nos. 1 and 2 and the size of the anticline, as well as its 

relation to the Cottonwood anticline, where the most productive 

sands outcrop, and to the structural depression of the Big Horn 

Basin, however, hold out little encouragement for finding important 

quantities of oil and gas on the structure.

GRASS GREEK ANTICLINE.

By D. F. HEWETT. 

GENERAL FEATURES.

The Grass Creek anticline (No. 34, PI. I) has been extensively 

explored by drilling in the Grass Creek Basin and has been shown to 

contain one of the best oil fields in Wyoming. It lies about 28 miles
152 ANTICLINES IN SOUTHERN PART OF BlG HORN BASIN, WYO.

northwest of Thermopolis and may be reached from Worland by the 

Gooseberry Creek road to the north end of the basin, from Kirby by 

the road up Sand Draw and Cottonwood Creek, and from Thermopolis by the old Cody stage road as far as the crossing of Grass 

Creek. Worland, Kirby, and Thermopolis are towns on the Chicago, 

Burlington & Quincy Railroad. Most of the heavy freight is brought 

into the basin through Kirby.

The Grass Creek Basin is one of the best examples of those surface 

basins that are almost completely surrounded by prominent escarpments or rim rocks. The rim of the basin forms a rude ellipse about 

7 miles long and 3 miles wide at the widest part. Although the rim 

(see PL XXIII, A) forms a nearly impassable wall 400 feet high on 

the northeast side of the basin, it is cut by several narrow notches 

on the north, west, and south, through each of which a road passes. 

The basin is drained by two streams, Canyon Coulee, which flows 

north and east to Gooseberry Creek, and Grass Creek, which flows 

east to Cottonwood Creek. The part of the basin drained by Canyon 

Coulee contains numerous low knobs and ridges and is sparsely 

covered with grass and sagebrush, but the slopes adjacent to Grass 

Creek are almost flat and, by the aid of water drawn by ditches from 

Grass Creek, several large tracts are cultivated and yield abundant 

crops of alfalfa and oats. The two drainage areas are separated by 

a low but conspicuous gravel-covered ridge which is part of a terrace 

that was once extensive.

For most of the year Grass Creek, which rises among the high 

ridges of the Shoshone Mountains, carries a surface flow that during 

the early summer months is used for irrigation. Water suitable for 

drinking may be found by digging shallow holes near the stream 

. channel. The surface flow at Little John's ranch after the irrigation 

season in September, 1913, a year of abnormal rainfall, was estimated at 40 gallons a minute. Several ranches depend entirely upon 

water from wells, which is used in spite of the excessive alkali content. The main fork of Canyon Coulee at the northwest end of the 

basin is dotted with pools of highly alkaline water, which are used 

only by cattle.

STRUCTURE.

The shape and size of the Grass Creek anticline is shown on the map 

(PI. XXIV, p. 160) by a cross section and by structure contours drawn 

at intervals of 200 feet on the lowest coal bed, the Dickie (Mesaverde 

formation), which appears to be continuous around the basin.

Well and surface data show the thickness of the Cody shale to be 

2,450 feet; and as the sandstone underlying the lowest Mesaverde coal 

bed is about 60 feet thick the approximate elevation above sea level 

of the top of the upper Frontier sandstone at any point may be found
U. S. GEOLOGICAL SURVEY

A. STANDARD DRILLING RIG IN GRASS CREEK OIL FIELD,

View westward toward the gap through which Grass Creek enters the basin. The character of the topography 

and vegetation is well represented.

ti. CROSS SECTION OF NORTHWEST END OF SPRING CREEK ANTICLINE. 

The heavy line indicates the outcrop of a folded bed in the Frontier formation.
CREEK ANTICLINE. 153

by deducting the sum of these two figures (2,510 feet) from the elevation of the coal bed shown by the contours.

The Grass Creek Basin is carved in the soft Cody shale, and the 

surrounding rim rock is formed by the massive sandstone beds at the 

base of the overlying Mesaverde formation. The interpretation of 

the part of the anticline lying beyond the rim rock is based on the 

dip and strike of beds that overlie the Cody shale; and that of the 

part lying within the rim rock is based chiefly on data gathered from 

the logs of wells. The sandstones of the Frontier formation which 

yield the oil in this anticline do not outcrop but are struck in wells 

at a minimum depth of 365 feet in the east side of sec. 13, T. 47 N., 

R. 99 W.

The contours show a relatively simple but sharp anticline broken 

by a few faults. The fold, as shown by the cross section (PI. XXIV), 

is unsymmetrical, with a steep limb on the southwest side and a very 

gently dipping limb on the northeast side. The dips on the northeast 

side increase from zero at the crest line to a maximum of 34° on the 

outcrop of beds of the Meeteetse formation 4 miles distant. The 

rim rock of Mesaverde sandstone dips from 12° to 24° (average 15°) 

along the northeast limb. On the southwest side the beds descend 

sharply into the adjacent syncline and dip from 50° to 60° across a 

wide belt. The anticline is limited on the northwest by a short syncline, west of which is the Little Grass Creek dome.

Although outcrops indicate that the only crest of the Grass Creek 

anticline lies in the W. £ sec. 18 and the NW. i sec. 19, T. 46 N., R. 

98 W., where it is well marked by the logs of the wells, the logs also 

show a smaller but fairly defined crest farther southeast in sec. 29, T. 

46 N., R. 98 W. The fault of 146 feet shown in the SE. i sec. 19, 

T. 46 N., R. 98 W., is based on the correlation of two near-by 

well logs.

In the Grass Creek Basin, according to the logs of 44 wells that are 

available, only one (No. 22), in the NW. \ sec. 19, has penetrated the 

rocks below the Frontier formation. This well, which is near the 

crest line of the anticline, extends to the persistent sandstone in the 

Thermopolis formation, where it struck gas under great pressure. 

This sandstone occurs in the same part of the Thermopolis shale as 

the sandstones which yielded considerable gas in well No. 2 in the 

Oregon Basin and which yielded gas with some oil in the well on the 

Shoshone anticline.

So far as can be inferred from well logs the Frontier formation is 

450 to 500 feet thick and contains several beds of sandstone. A tentative correlation of the logs of wells .within an area about 1£ miles 

wide by about 6 miles long indicates that four of the sandstone beds 

are persistent, and it is the local practice to refer to these from the
154 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

highest to the lowest, respectively, as the "water" sand, and the 

"first," "second," and "third" oil sands. Although such a correlation is useful to the driller it disregards the uncertainties that attend 

recognition of the exact character of the rocks passed through and 

assumes that the beds are essentially parallel and persistent a condition that probably does not exist. The maximum range in thickness of the four sands is 15 to 75 feet, but in most of the wells they are 

reported to be 20 to 30 feet in thickness. In the northern part of the 

basin, where the logs may be correlated with greatest assurance, the 

thickness of beds between the "water" sand and the "first" oil sand 

is about 190 feet; between the "first" and "second" oil sands about 

90 feet, and between the "second" and "third" oil sands, about 

90 feet. Locally there are other beds of sandstone, in some of which 

small quantities of oil and gas have been found.

In the southern part of the basin only a few wells explore more 

than the upper 300 feet of the Frontier formation, so that it is not 

known that the lowest sand is persistent. In this part of the basin, 

the zone including the "first" and "second" oil sands contains 

three sands, each of which, within the proved territory, contains 

some oil. Bentonite occurs in the Frontier formation in the Grass 

Creek Basin, and in some wells as many as eight beds of it have 

been struck. It causes much trouble in drilling, on account of its 

tendency to absorb water and greatly increase in volume.

Log of well (No. 12) in the NW. i sec. 18, T. 46 N., R. 98 W.

Cody shale: 

Shale ..................................... .

Frontier formation:

Bentonite. . .....................................................................

Mowry shale:

Thickness.

Feet. 

540

OK

7C

sn

10

30

25

6

14

30

15

5

21

10-

5

7

17

10

10

20

30

10

16

35

51

Depth.

Feet.

can

565

640

670

680

710

735

741

755

785

800

805

826

836

841

848

865

875

885

905

935

945

961

996

1,047
GRASS CREEK ANTICLINE. 155 

DEVELOPMENT.

Although it is locally reported that shallow wells were drilled 

during the summer of 1913, the first discovery of oil was made in 

June, 1914, in well No. 17 of the Valentine interests. There was 

considerable activity during 1914, and as the result of an examination of the field during August of that year Hintze 1 located 23 wells 

and gives the records of 16. On August 1, 1915, 55 wells had been 

completed, and in the preparation of this report the records of 44 

were available. During October, 1916, -the field was revisited by 

one of the authors and 193 wells had been completed. Of these, 

129 were producing on October 15, and 22 had struck water in the 

productive sands. Most of the remaining 42 wells had struck small 

flows of oil that did not pay to pump, but information concerning 

some is lacking. The logs of most of the existing wells are known, 

but it has not been deemed advisable to delay the publication of 

this report until all of the information to be obtained from them has 

been incorporated. There is in process of preparation a more complete report on the Grass Creek oil field, which will be published 

later.

In drilling, both stationary and portable rigs have been used. 

For generating power, coal from near-by mines was first used, but 

recently it has been displaced by oil and gas from a number of the 

wells, notably No. 22 in the NW. J sec. 19, T. 46 N., R. 98 W. The 

cost of drilling ranges from $2 to $3 a foot. The standard type of 

drilling rig is shown in Plate XXIII, A (p. 152).

Except in a few wells in the southeastern part of the basin the 

uppermost Frontier sandstone has yielded a little water and is 

locally known as the "water" sand. In several wells it contained 

small pockets of gas, and in one well, No. 61, in NE. £ sec. 29, it 

yielded several-, barrels of oil when pumped. Small and unimportant quantities of oil and gas are locally found in the stray sands 

between the top sand and the "first" oil sand, but the most important oil-bearing sands occur in the zone 100 to 150 feet thick, the 

top of which is 90 to 180 feet below the uppermost sand. Locally, 

as many as three oil-bearing sands are found in this zone. In 

three wells oil from these sands has flowed at the surface, but ordinarily it rises only several hundred feet and must be pumped. Oil 

'flowed from one well in the SW. J NE. 1 sec. 29, T. 46 N., R. 98 W., 

for three weeks after the well was "shot." Gushers, such as have 

been found in a part of the Salt Creek field, have not yet been found 

in the Grass Creek Basin. The maximum yield a day of the sands 

of this zone has not been established, because until the fall of 1915

1 Hintze, F. P., jr., Grass Creek oil and gas field, Wyo.: Wyoming Geol. Survey Bull. 11,1915.
156 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

there were no facilities for shipment or storage of oil, and most of 

the wells were capped.

It is the practice in the field to shoot the pay sands with from 60 

to 250 quarts of nitroglycerine when the well is completed. Under 

these circumstances the production of the good wells during the first 

24 hours ranges from 150 to 400 barrels. The production during the 

second 24 hours is less, and although the system of pumping now in 

use by the companies that operate in the field does not permit them 

to record the daily production of each well, it is known that the average production from groups of 15 to 20 wells on some of the central 

tracts soon declines to 50 to 75 barrels per well a day. The lowest 

sand of the Frontier formation has been penetrated by only a few of 

the wells, most of which are in the northern part of the basin, and 

although it contains oil its probable yield has not been determined.

Up to October, 1916, production was confined to the landlying south 

of the north boundary of sees. 19 and 20,T.46 N.,R,. 98 W., where most 

of the surface of the basin was covered by agricultural entries. It is 

apparent, therefore, that although wells have shown the presence of 

oil in a large area adjacent to the crest and north of the line referred 

to, the possible yield of the sands in this area is not known. The 

production of the district rose rapidly during the summer of 1916, 

owing to a great increase in the number of wells. It is estimated that 

the weekly production during October, 1916, was about 45,000 barrels.

Water has been struck in a number of wells along both limbs. The 

water commonly has a mildly alkaline taste, but none that is appreciably salty or sulphurous has yet been found. In most instances 

when the water is struck it rises from 10 to 50 feet in the well. More 

rarely it has risen about 200 feet, and in one well on the northeast limb 

it rose 900 feet, or within 200 feet of the surface. In that part of the 

field that has been most thoroughly explored the horizontal distance 

between wells that yield oil and those that yield water is not great. 

It therefore appears that in the productive sands a fairly defined 

surface of demarcation exists between oil and water.

Oil is pumped from groups of 5 to 20 producing wells by power 

supplied from centrally located plants. The oil is received in a settling tank which serves to separate any sediment and water that 

may have been raised during pumping and then flows to storage 

tanks. From these storage tanks oil is drawn directly by 3-inch 

pipes into the 6-inch pipe line which transports it to Chatham, on 

the Chicago, Burlington & Quincy Railroad. This pipe line was constructed early in 1915, and in a distance of 27 miles has a fall of about 

1,500 feet, so that the oil flows freely without pumping.

The following analysis of a sample of oil from well No. 35, in the 

NW. £ sec. 20, was made at the laboratory of the Bureau of Mines.
GEASS CREEK ANTICLINE. 157

The oil is from the zone that includes the "first" and "second" oil 

sands of the Frontier formation.

Analysis ofoilfrom well No. 35, in the NW. { sec. 20, T. 46 N., R. 98 W.

Began to boil at 80°.

Gasoline: Per cent. 

80°-1000 ................................................. 3

100°-125°................................................. 9

125°-150°................................................. 10

22 

Kerosene:

175°-200°................................................. 4

200°-225°................................................. 6

225°-250°................................................. 8

250°-275°.......................................... ...... 8

275°-300°.................................................. 8

42 . 

Residuum..................................................... 36

Specific gravity at 60° F.:

Crude oil (41° Baum^).................................... 0.8187

Gasoline (55.9° BaxuaA)................................... -7530

Kerosene (41.3° Baume)................................... .8175

Residuum (33.7° BaumS).................................. .8553

CONCLUSIONS.

The areal limits of the productive territory in the Grass Creek field, 

or the limits beyond which the sands contain water instead of oil, 

appear to be fairly indicated by the wells that have been drilled, 

although little is known concerning the possibility of finding oil in 

commercial quantities in the sandstones of the Thermopolis and lower 

formations. In the portion of the field north of the north boundary 

of sees. 29 and 30, T. 46 N., R. 98 W., the productive area in the 

Frontier sandstones appears to be roughly inclosed by the 7,200-foot 

contour on the lowest Mesaverde coal, and by the closely corresponding 4,700-foot contour that might be drawn on the uppermost sandstone of the Frontier formation. In the southeastern part of the field 

the limit is less clearly defined but appears to be inclosed by a lower 

contour on the Mesaverde coal, approximately the 6,700-foot, and by 

the equivalent 4,200-foot contour on the top of the uppermost sandstone of the Frontier formation. Several factors might account for 

this apparent difference in the level of the lower limit of oil, but the 

subject will not be discussed in this report. The gas, oil, and water 

in the middle zone of the Frontier formation appear to be arranged 

in the pervious beds in roughly horizontal zones, the gas lying close 

to the crest traces of the folded Frontier sandstones and being under-
158 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

lain successively by the oil and the water in accordance with the 

simplest conception of the anticlinal theory.

The present development of the Grass Creek field shows better 

prospects for the production of oil than any of the explored fields of 

the Big Horn Basin, although possibly not better than those of the 

Salt Creek fields, where wells of the gusher type are not uncommon 

and many wells have yielded considerable quantities of oil by natural 

flow for periods as long as five years. Exploration to date has shown 

the possible yield of pervious sands, of the Frontier formation, but it 

is not improbable that here, as at Salt Creek and other fields in the 

eastern slope of the Rocky Mountains, important quantities of oil 

may be found in lenses of sand in the thick shale or in fissures.

ENDS CHEEK ANTICLINE.

By D. F. HEWETT.

A small but well-developed fold (No. 35, PI. I) is exposed along the 

valley of Enos Creek, in the southwestern part of T. 46 N., R. 100 W., 

about 6 miles above the Dickie ranch on Gooseberry Creek. It is most 

easily accessible, however, from the Grass Creek Basin, the central part 

of which is 7 miles due east and which is 28 miles northwest of Thermopolis. Enos Creek is a* small perennial stream which rises among 

the timbered hills along t£Jy;eastem edge of the Shoshone Mountains 

and flows in a deep, narro^ ?alley to its junction with Gooseberry 

Creek. There are no ranches along the stream, and the adjacent 

region is devoted to grazing.

During 1916 a well was drilled near the crest line and at 2,400 feet 

struck water in the Torchlight (?) sand. On account of the position 

of the anticline with reference to the border belt of anticlines, the 

prospect for finding oil. or gas in this anticline is not good.

The anticline is marked by good exposures of the lower sandstone 

beds of the Mesaverde formation and the underlying shaly sandstone 

of the Cody shale. Erosion has produced a small basin along the crest 

of the anticline, and the lowest coal bed of the Mesaverde formation 

may be traced around the adjacent slopes and ridges. On the northeast side of the anticline, the beds of the formations successively 

higher than the Mesaverde dip uniformly at about 10° to the syncline 

which bounds the Grass Creek anticline on the southwest. The Mesaverde coal beds attain a maximum dip of 28° west along the west side 

of the anticline. The structure contours in figure 10 are based upon 

a traverse of the lowest coal bed, and show a small anticline that 

trends northwest, the highest part of which is situated where the crest 

line crosses Enos Creek. This reconnaissance did not permit the 

determination of the extent of the anticline northwest and southeast 

of the outcrops of the Mesaverde coal bed,
LITTLE GRASS CREEK DOME. 159

From April to October, 1916, a well was drilled near the west line 

of sec. 25, T. 46 N., R. 100 W., by the Grass Creek Oil Co. The top of 

the well has an approximate elevation of 6,440 feet, and at 2,400 feet 

the top of a bed of sandstone which is probably the uppermost bed of 

the Frontier formation was struck. This bed yielded a strong flow 

of water, which rose 1,000 feet in the well. At 2,436 feet tools were 

lost and drilling was temporarily discontinued.

The Enos Creek anticline is similar in size and structural relations 

to the Gooseberry anticline, situated about 7 miles north, which was 

also recently drilled to the upper Frontier sand and yielded water. 

As both of these anticlines are separated from the main structural

Section along line A-B

Structure contours (lines of equal altitude) , 

on top of lowest Mesaverde coal bed. Numbers 35 

show altitude above sea level. Solid lines indicate 

position of coal' bed where present,and broken lines 

former position of coal bed.

Contour interval, 100 feet

FIGUKE 10. Structure-contour map and cross section of the Enos Creek anticline (No. 35, Pl.l).

depression of the Big Horn Basin by other extensive prominent anticlines, they are not regarded as favorable reservoirs for important 

accumulations of oil and gas.

LITTLE GRASS CREEK: DOME.

By D. F. HEWETT.

The Little Grass Creek dome (No. 36, PI. I) is in the northeast 

part of T. 46 N., R. 99 W., adjacent to the northwest part of the 

Grass Creek anticline, from which it is separated by a short but pronounced syncline. The crest of the dome coincides with a nearly 

circular basin, about \\ miles in diameter, that is almost surrounded 

by a rugged escarpment of sandstone beds of the Mesaverde formation. The western part of the basin is drained northward by a tributary of Gooseberry Creek and the eastern part by the principal fork
160 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

of Canyon Coulee. There are no perennial streams in the basin, 

but Gooseberry Creek, half a mile north, flows on the surface most of 

the year. The basin is accessible by roads from the Grass Creek 

basin on the east and from Gooseberry Creek on the north.

One well near the crest is reported to have penetrated the upper 

half of the Frontier formation and to have encountered water in the 

sands. Another well on the east side of the dome is too shallow to 

have reached any of the Frontier sands. The dome appears to 

offer little prospect for the discovery of oil and gas in commercial 

quantities.

As shown by structure contours on the lowest coal bed (Dickie) of 

the Mesaverde formation, the dome is almost circular but merges 

westward with a flat anticline that can be traced a few miles farther. 

(See PI. XXIV.) The dips of the escarpment away from the crest 

of the dome are low, ranging from 7° to 12°, but the higher beds south 

of the rim dip as much as 34° S. The contours near the crest of the 

dome are based on the dip of outcropping beds. The low syncline 

that separates the dome from the Grass Creek anticline does not 

persist far north of the limits of the area shown on Plate XXIV and 

disappears southward near an extensive syncline. The low syncline 

would tend to divert to the crest of the Grass Creek anticline any oil 

or gas that was rising from the deeper part of the Big Horn Basin 

in the area east of the synclinal trough, but it would not prevent 

the movement to the Little Grass Creek dome of oil or gas from the 

area west of the trough.

If the thickness of the Cody shale is assumed as 2,450 feet, as at 

Grass Creek, the top of the uppermost Frontier sand lies about 1,800 

feet below the surface on the crest of the dome in the NW. J sec. 11, 

T. 46 N., R. 99 W. If the section of the Frontier formation is similar 

to that at Grass Creek the first oil sand would be struck 2,020 feet 

below the surface.

The Great Dome Oil Co. drilled a well reported to be about 2,100 

feet deep on the E. } sec. 10, T. 46 N., R. 99 W., but struck water in the 

upper Frontier sands. The log of this well has not been obtained. 

It is situated a short distance south of the crest line of the anticline 

and if important amounts of gas or oil were present in the dome, they 

should have been struck by the well. Failure to find either of the 

substances near the crest of the dome must be regarded as satisfactory 

proof that the lower parts of the dome are not favorable areas for 

exploration. The well in the E. £ sec. 11, T. 46 N., R. 99 W., is 

reported to be shallow and not deep enough to strike any of the 

Frontier sands.

The Little Grass Creek dome lies between the Grass Creek anticline 

on the southeast, in which oil has been struck by many wells, and the 

East Buffalo anticline on the northwest, on which two wells have
U. S. GEOLOGICAL SURVEY 

R.99 W. R. 98 W. BULLETIN 656 PLATE XXIV

STRUCTURE CONTOUR MAP OF GRASS CREEK ANTICLINE AND LITTLE GRASS CREEK DOME (Nos. 34 AND 36, RESPECTIVELY,

ON PLATE I) AND ONE CROSS SECTION

The outcrops of sands are mapped as sandstones

By D. F. Hewett

Wasatch -formation

Structure contours 

(lines of equal 

altitude) on top of 

Dickie coal bed. 

Numbers show 

distance above sea level. 

Solid lines indicate present 

position of bed below, and 

broken lines former position 

above presenb surface. 

Contour interval, ZOO feet'

o Drilling

 Oil well

<> Hole; no data

<!> Dry hole

Scale
EAST AND WEST BUFFALO ANTICLINES. 161

yielded gas. As the syncline between Little Grass Creek dome and 

the Grass Creek anticline disappears a short distance north of Gooseberry Creek, it probably does not prevent the migration-of oil or gas 

from the deeper part of the Big Horn Basin to the crest of the dome. 

The area from which these materials would tend to migrate to the 

crest is much smaller than that tributary to the Grass Creek anticline 

or the East Buffalo anticline, and is probably too small to permit 

important accumulations to be made.

EAST AND WEST BUFFALO ANTICLINES.

By D. F. HEWETT. 

GENERAL FEATURES.

The crests of the East and West Buffalo anticlines (No. 37, PI. I) 

are indicated by a few outcrops of the Cody shale in the large elliptical depression known as the Little Buffalo Basin, 34 miles southeast 

of Cody and 6 miles southeast of Meeteetse. Only two roads enter 

the basin: one from the west connects with a road along Iron Creek 

and Greybull River from Meeteetse, 10 miles distant; the other, 

entering through a notch in the east rim, joins the Meeteetse-Thermopolis road 10 miles southeast of Meeteetse. Freight may be 

brought into the basin most readily by the western route.

The basin is drained by Little Buffalo Creek, an intermittent 

stream that rises in some seeps outside the western rim and flows 

east and southeast to its junction with Gooseberry Creek. During 

the summer the stream bed contains a few pools of highly alkaline 

water in sec. 3, T. 47 N., R. 100 W., and sec. 5, T. 47 N., R. 99 W. 

The nearest water of fair quality is that of Gooseberry Creek on the 

south, but Greybull River, 5 miles to the northwest, offers a more 

dependable supply.

The Little Buffalo Basin is one of the most conspicuous of the 

surface basins west of Big Horn River. The rim of Mesaverde sandstone forms a rugged escarpment 200 to 600 feet high, and, except 

for two narrow notches cut by Little Buffalo Creek, completely 

encircles the flat basin. No roads and only a few trails cross the 

escarpment. The floor of the Little Buffalo Basin is made up largely 

of flat-topped low ridges which are remnants of a plain that once 

covered the entire basin.

STRUCTURE.

Two anticlines are indicated by the exposures of the Cody shale

within the basin. Their positions and forms, as shown by structure

contours on the second coal bed of the Mesaverde formation (PI.

XXV), are determined partly by observations of the writer and

86133° teull. 656 17 11
162 ANTICLINES IN SOUTHERN PAKT OF BIG HORN BASIN, WYO.

by the logs of wells that have been drilled since the field work was 

completed in 1912, and partly by the recorded observations of 

Hintze 1 in -connection with the field work in 1914. The only beds 

by which the structure of the central part of the basin may be determined are some sporadic outcrops of thin sandstone that are exposed 

in several dry ravines. In contrast with many other basins west of 

Big Horn Biver, where two or more anticlines or domes occur near 

one another, curves or offsets that correspond to the form of the anticlines are lacking in the bounding rim of Mesaverde sandstones, on 

the northeast side of the basin. There is a well-marked offset in the 

southwest rim, however.

The East and West Buffalo anticlines are among those that lie 

nearest the deeper central part of the Big Horn Basin. The beds 

rise gradually from the center of the Big Horn Basin to the outcrop 

of the Fort Union formation, northeast of Little Buffalo Basin, where 

the dip changes abruptly from 10° to 35°. From this point southwest 

the dips along the outcrops of the successively lower formations 

decrease gradually from 35° to the crest line of the East Buffalo 

anticline. Southwest of the crest line the dip of the beds increases 

abruptly to 28° as they descend to the deep syncline that crosses 

Gooseberry Creek. A shallow syncline separates the East Buffalo 

anticline from the West Buffalo anticline but does not extend 

beyond the rim of the basin on the northeast or southwest. The 

form of the West Buffalo anticline is poorly shown by outcrops of 

the Cody shale, but the Mesaverde sandstones attain a maximum 

dip of 36° near the gap through which Little Buffalo Creek flows in 

sec. 4, T. 47 N., R. 100 W. West of the rim of the basin the dips 

decrease gradually toward a syncline that extends northwest from 

Iron Creek.

No faults have been recognized in the outcropping beds in the 

Little Buffalo Basin, but on account of the steep dips on the southwest limbs of the anticlines small faults may occur in the Frontier 

sandstones, which are 1,200 feet or more below the surface on the 

crests of the anticlines.

The thickness of the Cody shale in the Little Buffalo Basin is 2,600 

feet, and of the part of the Mesaverde formation below the second 

coal bed 140 feet, so that the elevation above sea level of the upper 

Frontier sandstone may be found approximately at any point by 

deducting the sum of these two figures (2,740 feet) from the elevation of the coal beds as indicated by the structure contours.

The character of the lower part of the Cody shale and the upper part 

of the Frontier formation are shown in the following log of well No. 3:

> Kintze, F. F., jr.. The Little Buffalo oil and gas field, Wyo,: Wyoming Geol. Survey Bull. 11,1915.
Vife^S^^^?^7 '

o Drilling

 #-Gas welI

(? Hole; no data

Scale 62,soo

F=I 

Structure contours (lines of equal altitude) on 

top of Buffalo coal bed. Number shows elevation 

above sea level. Solid lines indicate position of coal 

bed where present, and broken lines -former position 

of coal bed. Contour interval, 200feet

3 MD.es

Wasatch formation

-< >- Dry 

STRUCTURE 

hole

CONTOUR MAP OF EAST AND WEST BUFFALO ANTICLINES IN LITTLE BUFFALO

BASIN, AND GOOSEBERRY DOME AND ANTICLINE (Nos. 37 AND 38,

RESPECTIVELY, ON PLATE I) AND CROSS SECTION

By D. F. Hewett
EAST AND WEST BUFFALO ANTICLINES. 163

Log of well No. S of Ohio Oil Co., West Buffalo anticline NE. \SW.\ sec. 2, T. 47 N.

R. 100 W.

Cody shale:

Frontier formation:

Sand, no water.. . ...............................................................

Sand............................................................................

Thickness.

Feet. 

20

9ft

440

25

715

1 ^

230

10

20

15

30

148

14

28

32

5

25

Distance.

Feet. 

20

40

480

505

1,220

i 93>;

1,465

1,475

1,495

1,510

1,540

1,688

i ?no

1,730

1,762

1,767

1,792

DEVELOPMENT.

In July, 1915, four wells on the anticlines had been completed to 

depths ranging from 1,680 to 1,792 feet. All were started and 

completed during the summer of 1914. In October, 1916, another 

well (No. 8) had been completed and three more were being drilled. 

The logs of two wells are available No. 3 through the courtesy of 

Mr. M. D. Woolery, of the Ohio OH Co., and No. 2 through Mr. W. L. 

Walker, representing W. L. Valentine. In addition, Hintze reports 

the log of the well No. 1 of the Midwest Oil Co. Three of these 

wells, which are situated (PI. XXV) on the limbs rather than close 

to the crest lines of the anticline, struck the top or Torchlight (?) 

sand of the Frontier formation at 1,370 to 1,465 feet from the surface 

and penetrated its upper 300 feet. The sand would have been 

found at a depth of about 1,100 feet if the well had been located 

in the NE. J NW. £ sec. 12, T. 47 N., R. 100 W., on the East Buffalo 

anticline and at a depth of about 1,270 feet in the SW. J NE. \ sec. 

3, T. 47 N., R. 100 W., on the West Buffalo anticline.

The sections of the Frontier formation are very similar in the 

three wells. The Torchlight (?) sand is reported as a single bed 62 

feet thick in well No. 1 and as four and six separate beds with similar 

aggregate thicknesses in the other two wells. Water under pressure 

is reported from this sandstone in each well, so that in this respect 

the conditions appear to be similar to those in Grass Creek anticline. 

Oil was not found in any of the wells, but several beds of sandstone, forming a group 105 feet thick, 145 to 155 feet below the base 

of the upper sand yields gas, locally under great pressure. The
164 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

possible yield of well No. 2 has been estimated, according to Hintze,1 

at 30,000,000 cubic feet per day, but all of the wells are now capped 

and produce several gallons of gasoline a day. The gas is used in 

the drillers' camps in the basin. Well No. 8 is reported to have 

struck water under pressure in the upper sands of the Frontier 

formation. The lower sands of the Frontier and the deeper formations have not been drilled.

CONCLUSIONS.

On account of discovery of gas under great pressure in wells near 

the crest of the Little Buffalo anticlines the lower or outer zones of 

the structures offer favorable sites for exploration for oil. The 

zone lying between the 6,800 and 7,200 foot structure contours on 

the north, northeast, and east limbs may be regarded as roughly 

outlining the area within which oil may be found. Further drilling 

near the crest of the anticlines should be discouraged until the outer 

zone has been explored. As few of the wells in the entire Big Horn 

Basin yield a natural flow of oil for more than a few hours after the 

productive sands are reached, it is desirable to retain as much gas 

pressure in the beds as possible.

GOOSEBERRY DOME AND ANTICLINE. 

By D. F. HEWETT.

The Gooseberry dome and anticline (No. 38, PL I) lie southwest 

of the East Buffalo anticline, in T. 47 N., R. 100 W., Park County, 

about 12 miles south of Meeteetse and 42 miles northwest of Thermopolis. The crests of both domes coincide with highly irregular 

surface basins that are surrounded by rugged escarpments of the 

lower sandstones of the Mesaverde formation. The western or upper 

basin contains a broad, flat tract about 100 acres in extent, part of 

which is under cultivation, at Dorr's (originally Renner's) ranch, on 

Gooseberry Creek. The eastern or lower basin contains no arable land.

Gooseberry Creek carries water on the surface throughout the year 

in this region, and in spite of its high alkali content is used for drinking at ranches.

On the Gooseberry dome the sandstones of the Mesaverde formation dip 7° to 11° toward a deep syncline on the east and 15° to 32° 

toward the west. The Gooseberry dome is separated from the Gooseberry anticline by a shallow syncline, which pitches southeast into 

an area that has not been examined. From this syncline the beds rise 

at 12° to 16° to the summit of the Gooseberry anticline and then 

dip 20° to 27° to a deep syncline on the west. The southern end of

i Hintze, F. F., jr., Little Buffalo oil and gas field, Wyo.: Wyoming Geol. Survey Bull. 11, p. 88,1915.
\ SUNSHINE AND SOUTH SUNSHINE ANTICLINES. 165

this anticline is covered by sandstone and gravel of the Wasatch 

formation.

Between September, 1915, and June, 1916, a well was drilled in 

the SE. J SE. J sec. 29 to a depth of 2,550 feet. A log of this well 

shows the first sand, Torchlight {?), dry at 1,725 to 1,740 feet, and 

other sands at 2,002 to 2,032 and 2,070 to 2,110 feet. It is reported 

that a flow of fresh water was struck at 2,032 feet and that the water 

rose to the surface. A smaller flow of brackish water, which also 

rose to the surface, was struck at 2,070 feet. It is also reported that 

when drilling in the lowest sand the bit became covered with a dark 

asphaltic material, but npne of the common evidences of oil were 

observed. The casing was placed to 2,272 feet.

It is apparent that if the first sand struck at 1,725 feet be regarded 

as the top of the Frontier formation, the well penetrated the entire 

formation but did not reach the "Muddy sand" in the Thermopolis shale. As this well was placed close to the crest line of the 

anticline and neither oil nor gas in appreciable quantity was struck, 

there is little prospect that other wells on this structure will find 

important quantities of these substances.

The Gooseberry dome is a structure similar in extent to the Gooseberry anticline but less pronounced. The dome is separated from 

the anticline by a low syncline, and though there is a possibility that 

it may contain oil or gas, if these substances were present in considerable amounts it would appear that more than traces would have 

been struck in the well on the anticline. The dome is therefore not 

regarded as a very favorable area for exploration.

In the event that a well may be drilled on the dome, it may be 

stated that from the depth at which the Torchlight (?) sand was 

struck on the anticline it has been calculated that the Cody shale is 

2,500 to 2,525 feet thick, and that on the crest of this dome this 

sand would be struck at 2,080 feet. A well that was much shallower 

than this could not be expected to reach the Torchlight sand.

SUNSHINE AND SOUTH SUNSHINE ANTICLINES.

. By D. F. EEWETT. 

GENEEAL FEATURES.

The Sunshine anticline (No. 40, PI. I) is a narrow fold that crosses 

Wood River, a tributary of Greybull River, a mile northeast of Sunshine post office, in sec. 21, T. 47 N., R. 101 W. Sunshine is 15 miles 

southwest of Meeteetse, which, next to Cody, is the largest settlement 

on the west side of the Big Horn Basin. Meeteetse is 38 miles south 

of Cody and 59 miles southwest of Basin, both-of which are on the 

Chicago, Burlington & Quincy Railroad. A stage makes the trip
166 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

between Sunshine and Meeteetse three times a week. Except for 

the disadvantage of great distance from the railroad, the Sunshine 

anticline possesses several natural advantages that facilitate exploration. Wood River carries an abundant supply of good water throughout the year, and the ranches along this s'tream and Greybull River 

furnish a supply of wild hay, alfalfa, oats, and produce. Lumber is 

available from sawmills on the tributaries of Wood River 10 miles 

above Sunshine.

. In the vicinity of Sunshine Wood River flows in an alluvial valley 

2,000 to 3,000 feet wide, most of which is cultivated by the aid of 

water drawn from the river by ditches. The valley is bounded on 

both sides by abrupt slopes of extensive residual areas of flat gravelcovered terraces that rise 200 feet above the river. Several small 

but prominent flat-topped ridges, also covered with gravel, rise 

about 300 feet above the lower terraces. These terraces lie between 

roughly parallel prominent escarpments of Mesaverde sandstones 

(PI. XXXI, B, p. 183), which may be regarded as limiting a higher 

and broader valley than the alluvial valley in which Wood Riyer flows.

STRUCTURE.

Although the Mo wry shale and upper part of the Thermopolis 

shale are exposed where Wood River crosses the anticline, outcrops 

are largely covered by alluvium of the river valley. The form of 

the anticline is shown by outcrops of Frontier sandstones which dip 

from 22° to 38° E. along the east limb and 30° to 46° W. along the 

west limb. The Frontier formation, which is well exposed, is 496 

feet thick on the west side of the anticline and contains four beds of 

sandstone, and is 540 feet thick on the east side of the anticline and 

contains six beds of sandstone, two of which correspond to one 

thick bed on the west side.

The Cody shale is poorly exposed along the limbs of the anticline, 

but the sandstones of the Mesaverde formation, which outcrop along 

the escarpments, dip from 9° to 20° E. on the east limb and 30° to 

55° W. on the west limb.

The structure contours (PI. XXVI) are drawn on the top of the 

Torchlight (?) sand and show a simple but narrow unfaulted anticline. 

The unsymmetrical nature of the fold.is shown by the steeper dip of 

the western limb and must here, as in similar anticlines, be taken into 

consideration in drilling. In those anticlines where the successively 

lower beds have similar forms the crest line or highest part of one 

bed does not lie vertically above that of a lower bed. (See p. 36 

and fig. 2, p. 35.) The crest line of the Torchlight (?) sand in the 

Sunshine anticline is 400 feet west of the crest of the sandstone near 

the base of .the Thermopolis shale.

'No faults were observed along the beds that outline the anticline.
U. S. GEOLOGICAL SURVEY R. 101 W. BULLETIN 656 PLATE XXVI

Scale 62,500

Structure contours (lines of equal 

altitude) on top of TorehlighU?) sand. 

Numbers show altitude above 

sea level. Solid lines indicate 

position of sand where present,and broken lines former position of the sand. On South Sunshine anticline, where 

data are mea£g.r,^all lines are broken.

*'" ^^-^ Contour interval, 200feet

-A,

3 MILES

Wasatch 

formation 

and volcanic 

tuffs

ENS RAVED AND PPINTEO BY THE U.S.aeOUJGlCALSURVf.Y

STRUCTURE CONTOUR MAP OF SOUTH SUNSHINE AND SUNSHINE ANTICLINES

(Nos. 39 AND 40 ON PLATE l) AND CROSS SECTION

The outcrops of sands are mapped as sandstones

By D. F. Hewett
SUNSHINE AND SOUTH SUNSHINE ANTICLINES. 167

The Sunshine anticline extends northwest of Greybull River into 

an area that has not been examined in detail, but it is known not 

to be continuous with the Pitchfork anticline in T. 48 N., R. 102 W. 

(See p. 171.) Its southward extension is also a matter of some doubt, 

as detailed work was not carried southward as far as Gooseberry 

Creek, and the divide between Gooseberry Creek and Wood River is 

so completely covered with gravel as to conceal all trace of the fold.

CONCLUSIONS.

As all the Frontier sandstones outcrop along Wood River the only 

sandstones which could carry oil and gfas and which remain buried 

on the Sunshine anticline are those of the Thermopolis, Cleverly, and 

Morrison formations. As gas was found in a bed of sandstone in 

the Morrison on Shoshone River * the presence of gas in this formation 

must be regarded as a possibility. No wells have yet been drilled, 

and although there is a fair prospect of finding gas in the buried 

sandstones the chance that commercially important quantities of oil 

will be found is not great. This conclusion is largely based on the 

area! relations of the anticline, as it lies between the southern part 

of the Fourbear anticline, 8 miles to the west, and the western anticline of the West Buffalo anticline, 8 miles to the east, which belongs 

to the basinward group of anticlines.

On Plate XXVI the smaller or South Sunshine anticline (No. 59, 

PI. I) is shown in the N. $ T. 46 N., R. 101 W., and the highest area 

is indicated at the point where the crest line crosses Gooseberry 

Creek. The position and form of this anticline were roughly deter- < 

mined during a rapid reconnaissance in the region by C. T. Lupton, 

in July, 1915. The anticline is most easily accessible from Sunshine 

by the road to Gooseberry Creek, but it may also be reached by the 

road up Gooseberry Creek from Dorr's ranch. In the region southeast of Wood River the streams have cut deep, precipitous valleys 

among high, rolling hills, and the only routes of travel lie along 

stream courses.

The outcrops that would show the relation of this anticline to the 

Sunshine anticline are concealed by Wasatch rocks, but as there 

are few places in the Big Horn Basin where the crests of two near-by 

anticlines lie in the same line it is inferred that this relation does not 

exist here. Beds of the upper part of the Morrison formation are 

exposed where Gooseberry Creek crosses the crest line of the South 

Sunshine anticline, and the Cleverly, Thermopolis, Mowry, and 

Frontier formations are exposed along Gooseberry Creek and along 9 

the steep walls of the valley in which this stream flows. The 

Frontier sandstones on the east limb dip about 40° E. and on the

i Hewett, D. F., The Shoshone River section, Wye.: U. S. Geol. Survey Bull. 541, p. Ill, 1914.
168 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

west limb about 30° W. Thus the east limb of the anticline has a 

steeper dip than the west, which is the reverse of conditions on the 

Sunshine anticline.

The only beds that are buried on the crest of the anticline and are 

known to yield oil or gas elsewhere in the Big Horn Basin are the 

sands in the middle of the Morrison formation and the Embar and 

Madison limestones. As this anticline is among the mountainward 

group of folds the prospect for the discovery of either oil or gas in 

these beds in quantities that are commercially important is not 

considered good.

FOURBEAB ANTICLINE.

By CHARLES T. LTJPTON. 

GENERAL FEATURES.

The Fourbear anticline (No. 41, PI. I) is so named from Fourbear 

(Lower Palette ranch), an abandoned post office near the crossing of 

the north end of the anticline by Greybull River. It is on the west 

side of the Big Horn Basin and lies mainly between Greybull River 

and its southern tributary, Wood River. No drilling for oil or gas 

has been done on this anticline, so that it is not known whether or 

not it contains these substances. The writer, however, judging from 

the shape of the fold and its position with relation to the probable 

edge of the basin, recommends part of it as being favorable for the 

accumulation of oil and gas. The anticline was not examined in 

detail but was visited on a reconnaissance trip by M. W. Ball and the 

writer in July, 1915. Fisher's x map shows this anticline and the 

formations that outcrop along and near it in a general way. Instead 

of being a series of domes, as might be interpreted from Fisher's map, 

it is a continuous anticline. (See PI. XXVII.)

The anticline is most easily reached from Cody, the western terminus of a branch of the Chicago, Burlington & Quincy Railroad, by 

stage over a good road which leads about 38 miles southeast to 

Meeteetse. From Meeteetse a fairly good road leads up the valley 

of Greybull River about 20 miles and a second-class road leads about 

5 miles farther, to the old Fourbear post office, where the anticline 

crosses the river and .extends southeastward. Other second-class 

roads cross the anticline along Franks Fork and Timber Creek. The 

south end of the anticline may be reached from Meeteetse over a 

fairly good road which follows Wood River to the mouth of Dick Creek 

and then over a wagon trail up Dick Creek to a point near its junction 

with Indian Creek. Parts of the anticline between the roads mentioned can be examined most easily on foot or horseback.

1 Fisher, C. A., Geology and water resources of the Big Horn Basin, Wyo.: U. S. Geol. Survey Prof. 

Paper53.pl. 3,1900.
\

U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XXVII

COMPILED MAP OF FOURBEAR ANTICLINE (No. 41 ON PLATE I)

By Charles T. Lupton

ENGRAVED *ND PRINTED BY THE U-S-GEOLOGICAL SUR
FOUBBEAB ANTICLINE. 169

The surface of the area (PI. XXVII) is crossed by the major valleys 

of Greybull and Wood rivers at the north and south ends of the 

anticline, respectively, and the minor valleys of Franks Fork, Timber, 

and Dick creeks. These valleys have cut steep-sided channels 200 

to 400 feet deep in the rocks across the crest of the anticline. In 

many places between streams hard rocks form the top of the upfold, 

and the anticline is marked at the surface by a ridge.

The water near this anticline is plentiful and of good quality, as 

practically all of the streams carry water direct from the mountain 

springs the year round; As the rainfall is much larger than it is in 

the interior of the basin it seems probable that the principal sandstone 

beds that may be penetrated by the drill also contain abundant water.

STRUCTURE.

The Fourbear anticline is a northwestward-trending upfold at least 

12 miles long. Its northwest and southeast ends are covered unconformably by Tertiary beds and rocks of volcanic origin, so that it is 

impossible to determine with certainty if the anticline plunges at each 

end or not. The anticline is apparently symmetrical in cross section 

but data on this point are lacking in places. Owing to the great mass 

of younger rocks that cover the older rocks to the west and southwest it is impossible to determine exactly the limits of the structural 

basin in that direction. It is entirely probable, however, from the 

position of the Owl Creek Mountains uplift to the south and from the 

presence of isolated patches of rocks of the same age as those exposed 

along the crest of the Fourbear anticline in and south of Yellowstone 

National Park that the structural basin from which this anticline may 

derive oil and gas may be of considerable extent, particularly to the 

southwest and west. From the presence of anticlines not far to the 

east and northeast it is apparent that little oil and gas can have 

reached the Fourbear anticline from the depths of the Big Horn Basin, 

for the anticlines have undoubtedly entrapped any that was migrating 

from that direction. If, therefore, Fourbear anticline is proved to be 

an oil or gas reservoir, these substances, in the writer's opinion, must 

have come for the most part from the west and southwest, where the 

oil-bearing rocks are covered by volcanic material.

In the reconnaissance trip along the crest of this anticline only a 

few dips were noted. Two at the northwest end near Greybull River 

show that near the crest the beds on the west dip as much as 60° and 

those on the east only 20°. Near the southeast end of the anticline, 

where the northeast limb is the steeper, a dip of 25° was noted on the 

northeast and 15° on the southwest side.

The lowest rocks exposed along the crest are believed to belong to 

the upper part of the Mowry shale, a formation about 300 feet thick,
170 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

which is characterized by large numbers of fish scales, and in which 

oil and gas are found in the Torchlight dome on the east side of the 

Big Horn Basin. Directly overlying the Mowry is the Frontier 

formation, 500 feet or more in thickness, which is characterized by 

predominantly sandy beds interbedded with sandy shale and shale and 

in places a little bentonite. Overlying the Frontier is the Cody shale, 

which in this locality is fully exposed only on the northeast limb of 

the anticline. The top of the anticline has been eroded, and its 

edges have been obscured by beds of the Wasatch formation that rest 

unconformably upon the Cretaceous formations beneath. The 

Wasatch ha turn is overlain by a great thickness of tuffs and flows of 

igneous rocks, which constitute the surface rocks over a broad area 

in the southwestern part of the Big Horn Basin.

Beneath the surface along the anticline are the lower part of the 

Mowry shale; the Thermopolis shale, about 600 feet thick, containing 

about 200 feet above its base a bed of sandstone (Muddy sand) 15 to 

20 feet thick, which yields gas in large amounts in the Oregon Basin; 

the Cleverly formation, ranging from 100 to 125 feet in thickness, 

with the Greybull sand at its top; and other formations.

No structure contours are drawn on the anticline, as the data on 

which to base them are too meager.

CONCLUSIONS.

In the writer's opinion the most important reservoir for oil and 

gas in this anticline is the Greybull sand, the top sandstone of the 

Cloverly formation, which contains practically all of the gas and oil 

derived from the Greybull field. The Muddy sand in the Thermopolis 

shale is believed to be the reservoir of the gas in the Oregon Basin 

and in other places in the western part of the Big Horn Basin, and it 

may be of value here. The highest part of the anticline was not 

determined, but it is probable that it is near the middle of the upfold 

(see PI. XXVII) between Franks Fork and Timber Creek. The 

writer advises that the initial drilling be done near the crest line of 

the anticline on either of these streams, for here water for drilling 

and camp use and wood for fuel are both abundant.

It should be kept in mind that from present knowledge of the extent 

of Big Horn Basin, the Fourbear anticline seems to be a mountainward structure, but there is the possibility that it is a basinward 

structure of a small structural basin now buried by tufaceous beds, 

and if so it may be a fairly good oil reservoir. Where the crest of 

the anticline crosses the creeks the Greybull sand, in which oil and 

gas may possibly occur, should probably be entered at a depth of 

not more than 900 feet.
ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO. 171 

PITCHFORK ANTICLINE. 

By CHARLES T. LTJPTON. 

GENERAL FEATURES.

The Pitchfork anticline (No. 42, PI. I) is in the northeastern part of 

T. 48 N., R. 102 W., near Greybull River and Rawhide Creek, in the 

western part of the Big Horn Basin. Although it has not been tested 

for oil and gas its shape and position with relation to the edge of the 

basin suggest that it may contain these substances.

The data contained in this brief report are based on observations 

made by M. W. Ball and the writer during a reconnaissance trip in 

1915, supplemented by data collected by a party in charge of E. G. 

Woodruff in 1907.

This anticline, although it lies about 55 miles from the nearest 

railroad point at Cody, the western terminus of a branch of the 

Chicago, Burlington & Quincy Railroad, is accessible with comparative 

ease, as good roads lead to the Pitchfork ranch, from which a secondclass road extends along its west flank. Detailed examination, 

however, must be made mostly on foot or horseback.

The surface of the anticline is characterized by a prominent ridge, 

the top of which approximately coincides with the crest line. (See 

fig. 11.) A low pass in the NE. \ sec. 14 of this township divides the 

ridge into two parts a narrow part at the north end and a broader 

part at the south end. In many places badlands are developed. 

The surface altitudes range from about 6,300 feet on Greybull River, 

at the south end of the anticline near the center of sec. 25, to about 

7,000 feet at the highest part of the ridge in the SW. \ sec. 11.

The water supply is derived entirely from Rawhide Creek and 

Greybull River at the north and south ends of the anticline, respectively. An irrigation ditch, which heads in Greybull River, crosses 

the south end of the anticline about a mile north of the river and 

would lessen the expense of obtaining water for camp and domestic 

use in and near the middle of the anticline. The intermittent 

streams which drain the greater part of the area and empty into 

Rawhide Creek and Greybull River carry water early in spring, in 

summer, and after heavy rainstorms. Water will undoubtedly be 

found by drilling in the sandstones of the Frontier formation, which 

outcrop along the anticline, for the formation carries much water in 

the Spring Creek anticline, a few miles north of Rawhide Creek. 

(See log, p. 176.)

STRUCTURE.

The Pitchfork anticline was not examined in detail, and information regarding it is meager. The writer noted the steeply' dipping 

beds on the west limb, and Woodruff measured one dip on the east
172 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

limb and several dips on the west limb adjacent to the outcrop of 

the coal bed. The anticline seems to be symmetrical, both limbs 

having about the same dip, and it apparently pitches at both ends, 

thus making the sandstones beneath the surface fairly good reservoirs for the accumulation of oil and gas. The maximum dip noted

R. 102 W,

?2 \*

\^ 

>&

J4

"\<5> vx- v

\<? \

24-

\Af\V

%^\X'^

FIGURE 11. Compiled map of Pitchfork anticline (No. 42, PI. I).

on the east limb is 45° in the NE. J sec. 14, and on the west limb 

63° in the SE. | sec. 23, near the south end of the anticline about onefourth mile west of the crest line. Westward from this point the beds 

gradually flatten into the syncline that roughly parallels the anticline.
PITCHFORK ANTICLINE. 173

The lowest rocks exposed at the surface on this anticline are 

believed to belong to the Mowry shale, a dark-gray to blue, hard, 

platy shale generally carrying fish scales in abundance. In places 

it contains one or more sands that in other fields are of economic 

importance as oil and gas reservoirs. Practically all the oil in the 

Torchlight dome near Basin, Wyo., is derived from sands in the 

Mowry shale. Overlying the Mowry is the Frontier formation, consisting mainly of sandstones with intercalated beds of shale and 

sandy shale. This formation, according to the log of the well on 

the Spring Creek anticline (p. 176), is about 300 feet thick less than 

it is at the south and east edges of the Big Horn Basin.

Beneath the surface on the crest of the anticline are the lower 

part of the Mowry shale, the Thermopolis shale, a dark-gray to blue 

shale 400 to 500 feet thick, containing near its middle in places in 

the Big Horn Basin a sandy phase known to oil drillers as the Muddy 

sand. This sand, which is 15 to 20 feet thick, is fairly persistent 

and is believed to contain gas in commercial quantities in the Oregon 

Basin. Directly underlying the Thermopolis shale is the Cloverly 

formation, the top sandstone of which, the Greybull sand, carries 

all the oil and gas so far discovered in the Greybull field and may 

contain oil or gas in the Pitchfork anticline.

Faults were observed along the west limb of the anticline, but the 

displacements are not great, the maximum being probably not more 

than 100 feet. It is not believed that they will seriously affect the 

accumulation of oil in the Greybull sand, as faults are numerous in 

the Greybull field, where they seem to have, no detrimental effect on 

the retention of the oil.

No structure contours are drawn, as the data obtained are not 

sufficient for this purpose. The position of the crest line of the anticline and the troughs of the adjacent synclines, however, give some 

idea of the extent and shape of the fold.

CONCLUSIONS.

No drilling has been done to determine whether or not the Pitchfork anticline contains oil and gas in commercial quantities. A well 

on the Spring Creek anticline, in the SW. | sec. 4, T. 48 N., R. 101 W., 

failed to find oil in the Frontier, Mowry, and Greybull sands, but this 

fact should not necessarily condemn the anticline, for its shape suggests that it may contain oil and gas in the sandstones below the 

surface, the most important of which are believed to be the Muddy 

and Greybull sands. A water well is reported to have been drilled 

to a depth of more than 1,500 feet at the Pitchfork ranch (fig. 11) 

without finding oil and gas; but this is not surprising, for the well 

is too far from the crest line of the anticline. The writer advises 

that the initial drilling be done near the crest line of the Pitchfork 

anticline, in the NE. i sec. 14 or the SE. f sec. 11, T. 48 N., R. 102 W.
174 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

SPUING CHEEK ANTICLINE.

By CHARLES T. LUPTON.

GENERAL FEATURES.

The Spring Creek anticline (No. 43, PI. I) lies on the west side of 

the Big Horn Basin in T. 49 N., Rs. 101 and 102 W., and in the 

northern part of T. 48 N., Rs. 100 and 101 W. One well, drilled 

near the crest line not far from the southeast end of the anticline c 

found no oil or gas, but did find water in abundance in the principal 

sands. From evidence obtained on a reconnaissance trip in July, 

1915, it seems probable that the anticline pitches southeast throughout the greater part of its length. If such is the case it has doubtful 

value as a reservoir for oil and gas, as these materials may have 

escaped to the surface at the outcrop of the beds along the east 

flank of the Carter Mountains, which lie a short distance northwest.

That part of the anticline which lies east of a north-south line 

through the weU in the SW. £ sec. 4, T. 48 N., R. 101 W., has been 

mapped in detail by D. F. Hewett, but the part lying west of this 

line has been examined only in a hasty manner. The location of the 

outcrop of the top of the Frontier formation at the northwest end of 

the anticline is based on observations made by M. W. Ball and the 

writer during a reconnaissance trip in July, 1915. The original field 

plats, made by a party in charge of E. G. Woodruff in 1907, also were 

used in locating the crest line near the northwest end of the anticline.

The anticline is most easily accessible from Cody, the western terminus of a branch of the Chicago, Burlington & Quincy Railroad. 

From this place a good stage road leads in a southerly direction to 

Meeteetse, about 38 miles distant. From Meeteetse a fairly good 

wagon road follows the valley of Spring Creek, which empties into 

GreybuU River a short distance to the north. The northwestern 

part is accessible not only from Spring Creek but also from a southern 

tributary of Meeteetse Creek, which crosses the northwest end of 

the anticline and empties into Greybull River a few miles north of 

the'town. The greater part of the surface of the anticline is comparatively smooth and can be traversed by wagons and automobiles 

almost everywhere except along the streams and at the extreme 

northwest end of the upfold, where the Frontier formation outcrops. 

(See PL XXIII, B, p. 152.) Here the country is too rough for vehicles and must be visited on foot or horseback.

The surface of the anticline is characterized by a comparatively 

smooth basin that has been eroded along the crest of the anticline. 

This is more noticeable at the southeast than at the northwest end,
SPRING CREEK ANTICLINE. 175

where the surface is made up of terraces cut by fairly narrow stream 

courses and of scattered prominent hills carried by the streams from 

Tertiary rocks.

A plentiful water supply is derived mainly from Spring and Meeteetse creeks and their spring-fed tributaries. The well drilled in 

sec. 4, T. 48 N., R. 101 W., found water in several sands, as other wells 

in this general locality would undoubtedly do.

Fuel for drilling and camp use consists of coal which outcrops 

along Greybull River near the mouth of Rawhide Creek, where three 

or four mines supply the general region. Other mines could probably 

be opened at much nearer places, for the coal bed is in the lower part 

of the Mesaverde formation, which surrounds the southwest end of 

the anticline. Some wood suitable for fuel grows on the uplands.

STRUCTURE.

The Spring Creek anticline is a well-defined upfold, the crest of 

which is marked in sees. 10, 11, 13, 14, and 24, T. 49 N., R. 102 W., 

by outcrops of Frontier sandstone and Mowry shale. (See PI. 

XXVIII.) The anticline is about 18 miles long, with its broad flank 

lying to the northeast. The southwest flank is comparatively narrow, ranging in width from 2 to 4 miles. The dips of the beds on the 

northeast limb range from zero at the crest line to 21° in the NE. £ 

sec. 7, T. 49 N., R. 101 W., and then gradually decrease toward the 

trough of the syncline several miles to the northeast. The southwest limb is much steeper than the northeast, the maximum dip 

being about 70° a short distance southwest of the crest line, in the 

SW. i sec. 11, T. 49 N., R. 102 W. From this locality southwestward the dips are believed to decrease gradually to zero. At the 

southeast end of the anticline the dips are comparatively gentle, 

ranging from 2° in sec. 30, T. 48 N., R. 100 W., to about 15° about 

2 miles farther southeast. No faults are known at any place along 

the anticline.

The oldest rocks exposed in the anticline, in sees. 10, 11, 13, 14, 

and 24, T. 49 N., R. 102 W., belong to the upper part of the Mowry 

shale, a hard, platy dark-gray shale about 400 feet thick, which is 

characterized wherever it has been recognized by large numbers of 

fish scales. In the Torchlight dome, on the east side of the Big Horn 

Basin, this shale contains two or more beds of sandstone that yield 

the greater part of the oil. Directly overlying the Mowry is the 

Frontier formation, about 500 feet thick, consisting mainly of sandstone, with minor quantities of shale and bentonite. This formation 

contains the sands that carry water in the well, whose log is given 

]belpw; and that also carry the oil and gas in the Grass Creek and
176 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

Little Buffalo Basin fields several miles to the southeast. Overlying 

the Frontier is the Cody shale, a dark-gray shale about 2,500 feet 

thick, and above this is the Mesaverde formation, about 1,200 feet 

thick, which carries coal of economic importance in its lower part. 

The structure contours are drawn on the top of the principal coal bed.

Beneath the surface in the anticline is the lower part of the Mowry 

shale. Underlying this is the Thermopolis shale, about 600 feet 

thick, which contains a very persistent sandstone known as the 

Muddy sand about 200 feet above its base. This sand, although it 

yields traces of oil and gas in different parts of the Big Horn Basin, 

is not known to carry them in commercial quantities except in 

Oregon Basin, where it is believed to yield a strong flow of gas. 

Directly underlying the Thermopolis is the Cloverly formation, the 

top sandstone of which the Greybull sand, about 20 feet thick 

yields practically all the oil and gas found in the Greybull field.

In order to show the character of the beds through which the drill 

passes, the log of the well drilled by the Peerless Oil Co. during the 

summer of 1915, in sec. 4, T. 48 N., R. 101 W., is given below.

Log of well drilled by the Peerless Oil Co. in sec. 4, T. 48 N., R. 101 W.

Soil........................................ ........................................

Shale, blue... . ......................................................................

Shale, brown. . ......................................................................

Shale...............................................................................

Shale...............................................................................

Thickness.

Feet. 

10

790

10

850

12

86

18

 114

15

15

35

35

20

20

45

70

125

40

Depth.

Feet. 

10

800

810

1,600

1,672

1,758

1,776

1,890

1,905

1,920

1,955

1,990

2,010

2,030

2,075

2,145

2,270

2,310

This well is reported to have been drilled about 100 feet deeper, but 

information regarding the lower rocks was not obtained."

CONCLUSIONS.

From the meager evidence at hand regarding the northwest end it 

is impossible to state with certainty whether or not the Spring Creek 

anticline pitches uniformly. The Frontier formation, which outcrops at .this end, in the east half of T. 49 N., K. 102 W. (see PI. 

XXVIII), is believed to pitch to the southeast, but southeast of the 

exposure a broad gravel-covered area obscures the outcrops and 

makes it impossible to determine whether or not a sag separates the
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XXVIII

Structure contours (lines of equal altitude) on top of Buffalo?coal bed

Numbers show distance above or below sea level. Solid lines indicate i >

present position of bed below, and broken lines former position

above present surface. Contour interval, 200 feet

STRUCTURE CONTOUR MAP OF SPRING CREEK ANTICLINE (No. 43 ON PLATE I)

The outcrops of sands are mapped as sandstones 

By D. F. Hewett and Charles T. Lupton

Scale 62,500

2 3 s Miles
FROST EIDGE DOME. . ' 177 '

northwest end of the anticline from the southeast end. If a sag is 

present, oil and gas would probably be trapped along the crest line 

of the anticline southeast of the sag. The northwest end of the anticline in the east half of T. 49 N., E. 102 W., may also be a favorable 

place at which to drill for oil and gas, particularly if the anticline 

pitches northwest at its northwest end. No information on this 

point was obtained.

FROST RIDGE DOME. j

By CHARLES T. LUPTON. (

GENERAL FEATURES. - .

*

The Frost Kidge dome (No. 44, PI. I) is a small upf old in the rocks 

that lies mainly in the northwestern part of T. 50 N., R. 101 W. It 

was not examined in detail but was observed by M. W. Ball and the 

writer on a reconnaissance trip in July, 1915. The outcrop of the 

Mesaverde formation and the dip symbols are from E. G. Woodruff's 

field sheets. The location of the dome and Freborg's ranch are beieved to be approximately correct.

This dome is most easily reached from Cody, the western terminus 

of the Chicago, Burlington & Quincy Railroad, 20 miles to the north, 

over the Cody-Meeteetse stage road to Sage Creek, and thence over 

a second-class road to the north edge of the dome in sec. 6, T. 50 

N., R. 101 W. To examine the dome in detail one must travel mostly 

on foot or horseback, as the surface is generally hilly and in places / 

cut into badlands. s*

The main water supply is from Sage Creek, which carries some water r . 

throughout the year and which lies within a mile of the west side of 

the dome. Springs of excellent water are present along the east slope 

of the Carter Mountains, a mile or more west of Sage Creek. A few ' 

seeps of poor water occur east of that stream.

STRUCTURE.

The dome is apparently nearly circular in outline, with comparatively Ibw dips, and is about a mile in diameter. A low syncline is 

believed to separate it from the monocline on the west, along which 

the Mesaverde formation outcrops. (See PL XXIX, p. 178.).

The lowest rocks outcropping at the top of the dome are believed 

to belong to the upper part of the Mesaverde formation, which constitutes the "Eagle" and the "Undifferentiated Montana," of Woodruff's 1 classification. Underlying the Mesaverde is the Cody shale,

i Woodruff, E. G., Coal fields of the southwest side of the Big Horn Basin, Wyo.: U. S. Geol. Survey 

Bull. 341, pp. 202-205,1909.

86133° Bull. 656 17 12
178 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

about 2,500 feet thick, which ranges in color from light to dark gray 

and consists mostly of shale, except near the top and base, where there 

are thin beds of sandstone and sandy shale. Directly underlying the 

Cody shale is the Frontier formation, about 500 feet thick, described 

by Hewett 1 as the " Middle member of the Colorado." The Frontier 

formation is the one that yields oil and gas in the Little Buffalo Basin 

and Grass Creek fields and is the most probable reservoir for these 

substances under the dome.

CONCLUSIONS.

No drilling is known to have been done on this dome, and it is 

questionable if oil and gas operators will investigate it until other 

more easily accessible anticlines and domes, in which the probable 

oil or gas bearing beds lie nearer the surface, have been tested. Before 

drilling, it would be advisable to make a detailed examination of the 

area so as to locate the test well as nearly as possible at the center of 

the dome.

HALF MOON ANTICLINE.

By CHARLES T. LUPTON. 

GENERAL FEATURES.

The data in regard to the Half Moon anticline (No. 46, PI. I) 

are based on the unpublished notes of a party in charge of E. G. 

Woodruff in 1907 and on observations by M. W. Ball and the writer 

during a reconnaissance trip in July, 1915. The information, however, is very meager.

The Half Moon anticline lies on the west side of the Big Horn 

Basin in the east-central part of T. 51 N., E,. 102 W., near the head 

of Sulphur Creek, which joins Shoshone River.a few miles west of 

Cody.

It is most easily accessible from Cody, the western terminus of a 

branch line of the Chicago, Burlington & Quincy Railroad, from 

which a good road follows in general the course of Sage Creek to a 

place a few miles east of the south end of the anticline. From this 

locality a good secondary road leads west and northwest along the 

south and west limbs of the fold. Any detailed examination must, 

however, be made on foot or horseback, as the surface is in most 

places too rough for vehicles.

The surface features of the southeastern part of the Half Moon 

anticline consists of a prominent ridge cut in several places by 

streams. The northwest half of the upfold is low and is much more

i Hewett, D. F., The Shoshone River section, Wyo.: TJ. S. Geol. Survey Bull. £41, pp. 94,97,98,1914.
S. GEOLOGICAL SURVEY

MO" T. 51 N. R. 1O2 W, R. 102 W.

BULLETIN 656 PLATE XXIX 

R.IOI W.

COMPILED MAPS OF FROST RIDGE. DOME AND HALF MOON ANTICLINE (Nos. 46 AND 47, RESPECTIVELY,

ON PLATE I) 

By Charles T. Lupton

Scale 6z,soo 

2 MILES
HALF MOON ANTICLINE. 179

dissected than the opposite half. The western limb has a smoother 

surface than the eastern.

Water may be obtained from intormittent streams that drain to 

Sulphur Creek. Along their valleys there are a few seeps that are 

of value for drilling but that are too alkaline to be of much use for 

camp purposes. A few miles to the west, however, along the northeast slope of Carter Mountain, good water may be obtained from 

several springs and could probably be piped with small expense to 

the west limb of the anticline. The incomplete Wiley ditch has been 

constructed across this anticline and, if finished, would supply an 

abundance of excellent water without hauling or piping.

STRUCTURE.

The Half.Moon anticline (PI. XXIX) in a northwestward-trending 

upfold faulted near the crest line, with downthrow on the west. It 

is about 3 miles long and, except for the fault, is apparently symmetrical. Definite information on this point, however, was not obtained, 

as the surface rocks west of the fault are for the most part covered 

with loose material. The east limb is about If miles wide and in 

places the beds dip as much as 40°. These high dips were measured 

not only at the "base of the Frontier formation but also at the base of 

the Mesaverde formation. Eastward and northeastward from the 

outcrop of the Mesaverde the dips gradually decrease to zero at the 

axis of a parallel syncline. The fault, which nearly coincides with 

the crest line of the anticline, passes into a gentle fold at its southeast 

end whose extent is unknown, as alluvium and loose material conceal it. No information is at hand regarding the northwest end of 

the anticline. A dip of 10° near the northwest corner of sec. 10, 

T. 51 N., K. 102 W., noted by Woodruff's party, suggests a pitch to 

the northwest.

The lowest rocks exposed near the crest of the anticline belong to 

the upper part of the Mowry shale, a dark-gray hard, platy shale 

about 200 feet thick, which, in the Torchlight dome on the east side 

of the Big Horn Basin, includes two or more beds of sandstone that 

carry oil and a little gas. A section of rocks measured by Hewett 1 

on Shoshone River near Cody shows that the Mowry shale, which is 

included in the upper 429 feet of the lower member of what he classed 

as Colorado, contains a few beds of sandstone. Overlying the Mowry 

is the Frontier formation, 400 to 500 feet thick, consisting mainly of 

beds of sandstone with minor amounts of shale and bentonite. This 

formation carries the oil in the Grass Creek field and gas in the Little 

Buffalo field.

1 Hewett, D. P., op. cit., p. 97.
180 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYQ.

The rocks underlying the surface on the crest of the anticline consist of the lower part of the Mowry shale; the Thermopolis shale, 

m about 400 feet thick; the Cloverly formation, about 125 feet thick; 

the Morrison formation, 200 or 300 feet thick; and lower formations. 

The Cloverly formation contains at its top a sandstone bed about 20 

feet thick which is known as the Greybull sand and which yields all 

of the oil and gas in the Greybull field. The middle part of the 

Thermopolis shale contains a persistent bed of sandstone known as 

the Muddy sand, which is generally present on the east and south 

edges of the Big Horn Basin and which is believed to yield the gas 

in the Oregon Basin.

Structure contours are not drawn on this anticline, as the data for 

determining them are too meager. The dip symbols, the crest line 

of the anticline, and the trough of the syncline indicate in a general 

way the extent and shape of the folds. Further examination is 

necessary to determine whether or not the anticline is of probable 

importance as an oil or gas reservoir, and the data furnished in this 

report are intended merely to draw attention to it.

CONCLUSIONS.

It is impossible to predict with certainty whether or not oil and 

gas will be found in the Half Moon anticline. If the sands have been 

sealed along the fault, oil and gas may be found in economic amounts 

in sands of the Frontier formation and of the Mowry shale in the 

western part of the upfold. East of the fault the Muddy sand and 

the top sandstone of the Cloverly formation (Greybull sand) are 

believed to be the only beds of possible value as oil or gas r.eservoirs, 

as the Mowry shale and overlying Frontier formation are eroded, 

thus permitting the escape of any oil or gas that they may have 

contained.

In September, 1916, the Flathead Valley B. C. Oil Co. started a well 

in the NW. | SE. £ sec. 26, T, 51 N., R. 102 W., which at the end of 

October had attained a depth of only 250 feet. No oil or gas had 

been found in that distance.

Any drilling on this anticline should be done with the knowledge 

that oil or gas in commercial quantities will only be found if the fault 

is sealed and if the west part of the anticline under cover lies favorably. 

Attention should be called to the fact that this anticline is apparently 

a mountainward fold, and it seems doubtful therefore that it contains oil and gas in commercial amounts.
ANTICLINES IN SOUTHERN PAET OF BIG HORN BASIN, WYO. 181 

OREGON BASIN NORTH AND SOUTH DOMES.

By D. F. HEWETT. 

* GENERAL FEATURES.

The Oregon Basin is a roughly elliptical depression about 4 miles 

wide and 13 miles long, the central part of which is about 12 miles 

southeast of Cody, in Park County. It is therefore one of the largest 

basins on the west side of the Big Horn Basin. Outcrops of the 

uppermost sandstone of the Frontier formation (see PI. XXXI, B) 

show the presence of two domes, the summit of the southern (No. 45, 

PL I) lying in sec. 32, T. 51 N., R. 100 W., and that of the northern 

(No. 47, PI. I), in sec. 5, T. 50 N., R. 100 W. Two wells drilled near 

the crest line of the south dome struck gas under great pressure, and 

the dome offers a good prospect for further exploitation. Of three 

wells near the summit of the north dome two appear to have yielded 

neither oil nor gas, while the third, located between the other two, 

has struck gas in several sands. The prospect for the discovery of 

important quantities of oil and gas is not so good as on the southern 

dome.

Unlike most of the basins of the region there are several drainage 

systems in the Oregon Basin, and the surface forms are diverse. The 

sandstones of the Mesaverde formation form a conspicuous escarpment around the northern and southern parts of the basin but are 

worn down to a series of low ridges for 9 miles along the east side 

and are wholly eroded for 5 miles along the west side. On the south 

the escarpment is broken by several narrow notches, some of which 

are important stream channels, whereas others represent faults. (See 

PI. XXX, A.) Two forks of Dry Creek, which rise in the low ridges 

east of the Carter Mountains, drain the southern part of the basin 

and discharge eastward through a broad gap. Along the north fork 

of Pry Creek rise several springs of water of fair quality, the most 

important of which is in the SE. £ sec. 12, T. 50 N., R. 100 W.; but 

during the summer months the lower courses of both forks contain 

only a few pools of highly alkaline water. The central part of the 

Oregon Basin is drained by Oregon Coulee, an intermittent stream 

which rises in the low hills west of the basin and joins Dry Creek several miles east of the basin. These two drainage systems are separated by a group of ridges that culminate in Elk Butte, an isolated 

flat-topped hill that rises 700 feet above the average elevation of the 

basin. The north end of the Oregon Basin contains a flat depression 

sunk 90 feet below the lowest outlet, in the center of which there is a 

small alkaline lake that evaporates and deposits alkaline salts during 

the summer months. A small area is cultivated at the Wiley ranch,
182 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

at the western edge of the basin, by the aid of water brought in from 

South Fork of Shoshone River, 15 miles west.

The stage road from Cody to Meeteetse crosses the western part of 

the Oregon Basin, and daily stages ply between these two towns. 

Roads from Greybull River valley also enter the basin from the east 

and southeast.

STRUCTURE.

Two domes, here called the North and South domes, are shown by 

outcrops of the Frontier sandstones and the Cody shale. (See PI. 

XXXII.) From the persistent syncline which limits the Spring 

Creek anticline on the northeast in T. 50 N., R. 101 W., and along the 

trough of which the Fort Union formation is exposed, the successively 

lower beds rise with low dips until, at the escarpment of Mesaverde 

sandstones in sees. 2, 1, and 12, T. 50 N., R. 101 W., a maximum dip 

of 36° is reached. From this point the dips decrease toward the 

South dome, which is marked by the sinuous outcrop of the uppermost Frontier sandstone. The South dome merges westward with 

the southern end of the extensive anticline that forms the Cedar and 

the Rattlesnake Mountains west of Cody. One small northwardtrending fault crosses the summit of the South dome and two groups 

of faults, some of which produce considerable offset, break the escarpment of Mesaverde sandstone that forms the southern boundary of 

the basin. One fault, in the eastern group, displaces the sandstone 

1,200 feet and produces at the surface a horizontal offset of the beds 

of 3,600 feet. (See PI. XXX, B.) The western limit of this fault 

has not been determined, but it appears to die out in the syncline that 

separates the North from the South dome. A fault of this extent 

must displace the Frontier sandstones 2,300 feet below the basal Mesaverde sandstone and may displace the sands in the Thermopolis and 

the Cloverly formations. The structure contours (PI. XXXII) are 

drawn on the East Wiley coal bed of the Mesaverde formation, which 

is separated from the uppermost Frontier sandstone by the Cody 

shale, 2,300 feet thick, ,and by the lower 224 feet of the Mesaverde 

formation. In the vicinity of the summit of the two domes the 

structure contours coincide closely with the inferred form of the 

uppermost Frontier sands.

Only the Torchlight sand (?) (the uppermost sandstone of the Frontier 

formation) outcrops on this dome (see PI. XXXI, B), but the beds 

between it and the sandstone near the base of the Thermopolis 

formation are recorded in well No. 2 of the Enalpac Oil & Gas Co., 

which was drilled near the summit of the dome.
U. S. GEOLOGICAL SURVEY

A. OUTCROP OF THE MASSIVE BASAL SANDSTONE AND COAL-BEARING PART OF THE 

 . MESAVERDE FORMATION IN SEC. 24, T. 52 N., R. 100 W.

H. FAULT IN SEC. 2, T. 50 N., R. 100 W.

Middle part of the Mesaverde formation (right) abuts aerainst upper part of the Meeteetse formation (left). 

Horizontal offset, 3,000 feet; stratigraphic displacement, 1,250 feet.
U. S. GEOLOGICAL SURVEY BULLETIN 656 PLATE XXXI

A. ESCARPMENT OF BASAL SANDSTONE OF MESAVERDE FORMATION DISSECTED NEAR 

CREST OF LOW DOME IN SECS. 15, 16, 21, AND 22, T. 47 N., R. 100 W.

H. OUTCROP OF THE UPPERMOST SANDSTONE (TORCHLIGHT (?) SANDSTONE MEMBER) 

OF THE FRONTIER FORMATION, EAST OF ELK BUTTE, IN SEC. 32, T. 51 N., R. 100 W.

Well No. 2 was later drilled under the low escarpment on the left.
OBEGON BASIN NORTH AND SOUTH DOMES. 183 

Log of well No. 2 of the Enalpac Oil & Gas Co., South dome of Oregon Basin.

Soil .................................................................................

Frontier formation: 

Sand............................................................................

Shale. ..........................................................................

Sand. ...........................................................................

Mowry shale:

Sand........................-.-.-...-.-.--.-.--.-..-.----.:.-.-.................

Shale, light.... . .................................................................

Thermopolis shale:

Shale . ..........................................................................

Thickness.

Feet. 

2

18

40

221

39

60

10

105

20

41

39

20

40

10

4

231

105

10

10

215

45

' 46

Depth.

Feet. 

2

20

60

281

320

3'0

380

485

605

546

585

605

645

655

659

890

QQH

1,005

1,015

1,230

1,275

1,321

Two wells, Nos. 1 and 4, were drilled southeast of well No. 2. 

No. 1 penetrated the uppermost Frontier sandstone only, but No. 4 

went down to the middle of the Mowry shale. The records of these 

wells show that the sandstone beds of the Frontier formation are 

highly lenticular and can not be traced for great distances. A 

single bed of bentonite is reported in well No. 2, but three such beds 

are reported from the same part of the section in well No. 4.

The summit of the North dome is not so well shown on the surface as that of the South dome. Only the uppermost sandstone 

of the Frontier formation outcrops, but other formations were penetrated in well No. 3 of the Enalpac Oil & Gas Co., which was drilled 

near the summit and penetrated as far as the middle of the Morrison 

formation.

Log of well No. 3 of the Enalpac Oil & Gas Co., North dome of Oregon Basin, sec. 5,

T. 51 N., R. 100 W.

Soil.................................................................................

Frontier formation:

Sand............................................................................

Shale, light. ....................................................................

Sand. ...........................................................................

Slate. ...........................................................................

Sand.........................................................:..................

Thickness.

Feet. 

49

121

5

65

20

120

20

20

27

51

42

11

27

Depth.

Feet.

4Q

170

175

240

9Rft

380

400

420

447

498

fun

553

580
184 ANTICLINES IN SOUTHERN PART OP BIG HORN BASIN, WYO.

Log of well No. S of the Enalpac Oil & Gas Co., North dome of Oregon Basin, sec. 5, 

T. 51 N., R. 100 W Continued.

Mowry shale:

Sand............................................................................

Sand, black .....................................................................

Sand............................................................................

Shale......................... ...................................................

Sand, dark. .....................................................................

Shale. . .........................................................................

Sand............................................................................

Thermopolis shale: 

Shafe............................................................................

Sand........... .................................................................

Shale...:.....................-..-...........-...................................

Cleverly formation: 

Sand............................................................................

Morrison formation: 

Lime, red. ......................................................................

Sand, broken. ..................................................................

Eock, red .......................................................................

Shale. ..........................................................................

Sand............................................................................

Shale................................... ..................... . . ... ...

Sand. ...........................................................................

Thickness.

Feet.

1 Q

13

4

80

10

10

27

16

10

36

5

77

5

439 ' 44

151

145

40

76

4

40

17

53

15

7

70

6

162

Depth.

Fed. 

598

611

615

695

705.

715

742

758

768

8Q4

809

886

891

1,330

1,374

1,525

1,670

1,710

1

7cc

1 790

1*830

1,847

,900

.915

,922

QO9

,998

2,160

Another well, No. 5, was drilled to the base of the Frontier formation half a mile west of No. 3; and a third, No. 6, was sunk to the 

uppermost Frontier sandstone near the lowest point of the syncline 

between the two domes. During 1916 another well, No. 9 (new 

No. 5), was drilled near the summit of the dome. On November 5, 

1916, it had attained a depth of 1,495 feet and was drilling in beds 

of the Morrison formation.

The Wasatch and later formations that cover the surface of much 

of the centra] part of the Big Horn Basin unconformably overlie 

the Meeteetse, Lance, and Fort Union formations along a narrow 

belt east of the Oregon Basin and were therefore laid down after the 

larger anticlinal folds had been formed. Although it is improbable, 

pronounced folds may occur in beds older than the Wasatch and 

younger than the Mesaverde in the belt where these beds are covered 

by the Wasatch formation. A low northwestward-trending syncline 

is shown by outcrops of the Wasatch formation in the north half of 

T. 50 N., R. 99 W., and it is doubtful whether the deeply buried 

Frontier sandstones rise without reversed dip from the center of the 

Big Horn Basin to the domes of the Oregon Basin.

DEVELOPMENT.

The domes of the Oregon Basin were among the first of those on 

the west side of the Bighorn Basin to be tested for oil and gas. The 

first wells were drilled by the Enalpac Oil & Gas Co. in the winter
U. S. GEOLOGICAL SURVEY 

R.I 01 W,

BULLETIN 656 PLATE eXXXJi 

R.IOOW.

\w«

^^4M1 \\\\\\^

/ " '

'I 111 \l 1,11 111I

 { " .' / I / / / . v ^. / .* ^ i

V\\\A

55P3A

Structure contours (lines -of equal altitude) on top 

of East Wiley coal bed. Numbers show distance 

above sea level. Solid lines indicate present position of bed below, and broken lines former posWasatch formation

ition above present surface. Contour interval, 200 feet

South Oreqon Basin dome - 3 tSTRUCTURE CONTOUR MAP OF SOUTH AND NORTH OREGON BASIN DOMES (Nos. 45 AND

48, RESPECTIVELY, ON PLATE I) AND CROSS SECTION

The outcrops of sands are mapped as sandstones

By D. F. Hewett
OREGON BASIN" NORTH AND SOUTH DOMES. . 185

of 1911 and 1912. By November, 1916, eight wells were completed, 

two near the summit of the North dome, five on the South dome, and 

one between these two groups. Another well was being drilled at a 

depth of 1,495 feet on the North dome. Although the company has 

submitted the logs of these wells data concerning the occurrence of 

oil, gas, or water in all except two were withheld. It is well known 

in the region, however, that wells Nos. 2 and 8, near the summit of 

the South dome, struck gas under considerable pressure. In the 

first well the gas came from the "Muddy sand" near the base of the 

Thermopolis shale and could not be controlled for several months. 

Late in the fall of 1912 the gas was used in the company's camp near 

the well. It is reported that water was struck in the uppermost Frontier sandstone in well No. 1.

Well No. 7, commonly known as the Jack well, attained a depth of 

1,826 feet, and from the log appears to have penetrated the Greybull 

sand, but except for a show of oil and gas near the top of the Frontier 

formation found only small flows of water in most of the sands.

Well No. 9 (new No. 5), in the SE. J NW. | sec. 5, T. 51 N., 

R. 100 W., on the North dome, struck small amounts of gas and 

water at several horizons on the Frontier formation, Mowry shale, 

and Thermopolis shale. The Greybull sand (?), however, has temporarily yielded much larger flows of gas.

No seeps of oil are known in the Oregon Basin, but here and there 

along the dry stream courses a black sciim occurs that might be 

mistaken for oil residuum. The scum has no odor and unlike residuum forms an emulsion with water. It appears to be an organic 

substance that is leached by alkaline water from the coal beds of 

the Meeteetse formation and deposited by evaporation.

CONCLUSIONS.

If no drilling had been done, the position of these two domes 

with respect to the large depression of the Bighorn Basin would 

indicate that they were fairly favorable territory for exploration. 

The discovery of an exceptional quantity of gas in a well on the crest 

of the South dome may be regarded as consistent with this hypothesis 

and as a favorable augury for the finding of oil farther down on the 

limbs. The presence of water in well No. 7 in the sands from the 

Mowry to the "Cloverly" formation indicates that the surface belt 

on the South dome, within which oil may be found, is not great. 

In the lack of definite information as to what was found in the two 

old wells near the summit of the North dome it may be safely assumed, that no exceptional quantities of either gas or oil were found. 

Unless the numerous faults that break the limiting escarpment of 

the Mesaverde sandstones be regarded as evidence that the possible 

oil-b.earing sands of the Frontier and lower formations are also much 

broken by faults, there is no apparent reason why the North dome
186 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WTO.

should not prove as favorable for the accumulation of gas as the 

South dome. The evidence from the Greybull field and from fields 

in other parts of Wyoming appears to show that faults trending approximately 90° from the strike of an anticline do not greatly prevent 

tlie accumulation of oil and gas. The directions of some of the 

faults of the North dome of Oregon Basin are obscure, and there 

may be more faults than are shown on Plate XXXII. It is possible 

that the faults have affected the accumulation of oil and gas on the 

North dome, and that instead of occurring near the summit the 

greatest amounts of these substances will be found in some of the 

blocks bounded by fault planes on the east side of the crest. It is 

probable, however, that an important cause of the absence of important quantities of either oil or gas along the summit of the North 

dome is the presence of the synclinal axis in T. 50 N., R. 99 W., 

which would hinder if not prevent the migration of these materials 

from the deeper part of the Big Horn Basin to the summit of the 

dome.

SHOSHONE ANTICLINE.

By D. F. HEWETT.

The crest of the Shoshone anticline (No. 48, PI. I) crosses Shoshone 

River in sec. 28, T. 53 N., R. 101 W., about 2 miles northeast of 

Cody. The map (fig. 12) is based in part on observations made in 

studying the section along Shoshone River in 1911 1 and in part 

on a reconnaissance by C. T. Lupton north of the river in 1915. 

The Cody branch of the Chicago, Burlington & Quincy Railroad 

crosses the crest line of the anticline on the north side of the river, 

and the region adjacent to the anticline is most accessible from roads 

that diverge from Cody station to the northeast and north.

The work of Fisher in 1904 and Woodruff in 1907 in this region 

shows that the anticline extends 5 miles northwest of the river, 

but the information available is not sufficient to warrant the construction of structure contours. The beds that mark the anticline 

are well exposed in the gorge through which Shoshone River flows, 

and there are also good exposures along the lower course of Cottonwood Creek, an intermittent stream that joins Shoshone River at 

the point where the crest of the anticline crosses the river. As 

large areas near the anticline both north and south of the river are 

parts of extensive gravel-covered terraces good outcrops are uncommon and the position of the crest line of the anticiine is not 

accurately known.

The lowest rocks that are brought to the surface along the anticline 

belong to the Frontier formation, the upper 300 feet of which outcrops. On the northeast limb of the anticline the uppermost sandstone of the Frontier dips 53° E. and beyond this the successively

» Hewett, D. F., op. cit., p. 89.
SHOSHONE- ANTICLINE. 187

higher beds range in dip from 35° to 58°, until along the outcrop of 

the upper part of the Fort Union formation the dip decreases abruptly 

to 3°. Southwest of the crest line the beds dip at a maximum of 

62° to a synclinal axis, beyond which they rise to a low anticline,

SECTION ALONG LINE A 

Scale oFmap and section

FIGURE 12. Reconnaissance map and cross section of part of Shoshone anticline (No. 49, PI. I).

referred to heretofore as the Cody anticline. Judging from the 

exposures along Shoshone River this anticline is without doubt the 

southeast end of that which brings the Sundance formation to the 

surface 5 miles northwest of the river.

Three wells have been drilled along the Shoshone anticline north 

of the river, in sees. 28, 21, and 17. There is no record of the log of 

the oldest well, No. 2, but it is reported to have attained a depth of 

850 feet; and in 1911 small amounts of oil, water, and gas spasmodically issued from the casing. Well No. 1 of the Shoshone Oil Co. c 

was drilled intermittently from 1909 to 1912 and is reported to have
188 ANTICLINES IN SOUTHERN PART OF BIG HORN BASIN, WYO.

reached a sandstone in the Morrison formation at a depth of 1,720 

feet. This well was started about 200 feet from the top of the 

Frontier formation and found small amounts of oil in the Mowry 

and Thermopolis formations and gas in the Thermopolis, Cloverly, 

and Morrison formations. The greatest amount of oil came from the 

sandstone near the middle of the Thermopolis shale, but the total 

production from the well, which was not pumped, did not exceed 

200 barrels.1 Both this and the foregoing well were located close 

to the crest line of the anticline.

Little information is available concerning well. No. 7, which is 

reported to have been drilled during the summer of 1914 by the 

Montana-Wyoming Oil Co. It was started in the Cody shale but 

apparently did not reach the Frontier sandstones. Water at present 

stands in it about 250 feet below the surface.

Since 1914 six wells have been drilled on the south side of the river 

by the Mountain States Oil Co. Five of these wells were drilled on 

an area scarcely 700 feet in diameter, but nothing is known about the 

logs of two, Nos. 3 and 5. Well No. 4 struck oil in the lowest Frontier 

sand at 175 feet, and for the first few days that it was pumped yielded 

10 barrels of oil a day. The well was shot, and after yielding 40 

barrels water came in and shut off the flow of oil. The drilling rig 

was then moved 25 feet east and another well sunk 700 feet without 

striking any oil or gas. Well No. 6 was drilled 200 feet but did not 

strike oil or gas. The sixth well, whose location is not shown on 

figure 12, was drilled about 4,000 feet southwest of No. 6 to a depth of 

1,350 feet. Water having a sulphurous odor and alkaline taste was 

struck in a sand that is probably the uppermost of the Frontier formation and now flows from the mouth at the rate of 10 gallons a minute. 

Gas bubbles freely from the surface of the water. This well is located 

near the trough of the syncline which lies between the Shoshone and 

Cody anticlines.

In 1916 the Ohio Oil Co. drilled a well in the W. £ sec. 27, T. 53 N., 

R. 101 W. The exact position of this well was not determined, and 

complete information concerning the log is not available. It is 

reported to have reached a depth of 2,115 feet and to have passed 

through the entire section of the Frontier formation without finding 

important quantities of oil or gas.

The position of the highest area on the crest of the Shoshone anticline is not known, but from available data it would appear to lie in 

the NE. 1 sec. 20, T. 53 N., R. 101 W. If, as seems probable, the 

well of the Montana-Wyoming Oil Co. did not penetrate deeper than 

the top sandstone of the Frontier formation the possibilities of this 

anticline have not been determined. Its position with respect to the 

central trough of the Big Horn Basin is sufficiently favorable to warrant further exploration near its crest, in sec. 20, T. 53 N., R. 101 W.

» Hewett, D. F., op. cit., pp. Ill, 112.
INDEX.

A. Pago.

Accessibility of the Big Horn Basin.......... 14

Accumulation of oil and gas, hypotheses as to. 46-47 

Acknowledgments for aid.................... 12-13

Ahrens, Otto, acknowledgment to............ 12

Amsden formation, nature of................ 17

Analyses of gas.'......................-... 53,65,66

Analyses of oil.................. 51-52,64-65,80,157

Anticlinal theory, essentials of............... 42-43

Anticline, definition of....................... 30

Anticlines, data concerning.................. 48-49

productiveness of........................ 43-46

structure of.............................. 33-36

wells on................................. 42

Axis, definition of........................... 30-31

B.

Ball, M.W., work of......................... 13

Basin, use of gas in.......................... 12

Bentonlte, occurrence of............... 154,170-175

Big Horn Basin, map of southern part of..... 14

Big Horn River, Peay sandstone member of 

Frontier formation on, plate 

showing......................... 21

Big Muddy oil field, position of.............. 46

B igtrails, section of Frontier formation near.. 22

Black Mountain anticline, description of 123-124,125

plate showing............................ 121

structure-contour map of................ 126

structure of............................ 124-125

Blue Spring anticline, description of... 129-130,131 

structure of............................ 130-131

structure-contour map of................. 134

Bonanza, section of Frontier formation near.. 21 

Thermopolis and Mowry shales near,

plate showing................... 20

Bonanza anticline, description of............. 93-94

development of.......................... 96-97

structure-contour map of................. 98

structure of.............................. 94-96

Bonanza region, drilling in................... 33-54

Brokenback anticline, description of... 102-103,105 

structure-contour map of.................. 102

structure of............................ 103-104

Tensleep sandstone on, plate showing.... 16

Bud Kimball anticline,description of..... 115-116,

118-119 

structure-contour map of................. 114

structure of............................ 116-118

Buffalo Basin anticline, drilling in........... 55

Byron oil field, drillingin ................... 54

position of............................... 46

C.

Campbell, M. B., organization and supervision by....................... 7-8,13

Carboniferous system, formations of.......... 17-18

Page. 

Cherry, L. E., acknowledgment to........... 12

Cherry anticline, description of........... 67-68,69

development of.......................... 69-70

structure-contour map of................. 68

testing of................................ 55

Chugwater formation, nature of.............. 18

oil in.................................... 41

on No Wood Creek, plate showing....... 17

Climate of the Big Horn Basin............... 15

Cloud Peak, elevation of..................... 32

Cloverly formation, nature of................ 19

oil and gas in............................ 41

unconformable contact of, with Morrisou

formation, plate showing........ 20

Cody, section of Frontier formation near..... 23

Cody shale, nature of........................ 24-25

Cottonwood anticline, description of... 147-148,149 

section of Frontier formation on.......... 24

structure-contour map of................. 150

structure of............................ 148-149

Cottonwood Creek, section of Frontier formation south of.................. 24

Crest, definition of........................... 31

Crestline, definitionof....................... 31

Crest trace, definition of..................... 31

Cretaceous system, formations of............. 18-27

D.

Dome, definition of.......................... 30

Domes, data concerning..................... 48-49

productiveness of........................ 43-46

structureof.............................. 33-36

wells on................................. 42

Drilling rig, portable, plate showing......... 78

standard, plate showing................. 152

Dry Creek, Fort Union and Lance formations

on, plate showing................ 26

Dry Dome, description of................... 81-83

E.

East Buffalo anticline, description of...... 161,164

development of........................ 163-164

structure-contour map of................ 162

structure.of........................... 161-163

Economic reports on areas in Wyoming,

list of........................... Sr-9

Edgett, C. M., acknowledgment to.......... 12

Elk Basin oil field, drilling in............... 55

position of............................... 46

Embar formation, nature of................. 17-18

near head of No Wood Creek, plate showing.............................. 17

Emery, W. B., work of...................... 13

Enalpac Oil & Gas Co., logs of wells of, in

Oregon Basin................. 183-184

189
190 INDEX.

Enos Creek anticline, description of....... 158-159

testing of................................ 55

Escape of oil and gas from outcrops.......... 42

Evans, H. C., work of....................... 13

F.

Fault in sec. 2, T. 50 N., R. 100 W., plate

showing......................... 182

Faults, influence of.......................... 60-61

position and extent of................... 36-37

Field work, division of...................... 13-14

Fisher, C. A., acknowledgment to........... 13

Formations, correlation of................... 16

Fort Union formation, angular unconformity 

of, with Lance formation, plate 

showing......................... 26

nature of................................ 28-29

uncomfonnable relations of.............. 33

Fourbear anticline, compiled map of........ 168

description of..................... 168-169,170

structure of........................... 169-170

Frontier formation, in Lysite Mountain anticline, plate showing............. 21

nature of.......................-..--...- 20-24

oilandgasin............................ 41,42

on Big Horn River, plate showing....... 21

outcrop of uppermost sandstone of, plate

showing......................... 183

Frost Ridge dome, compiled map of......... 178

description of......................... 177,178

structure of........................... 177-178

Fuel resources of the Big Horn Basin........ 16

G. '

Gas, analyses of.......................... 53,0.3,66

mode of occurrence of................... 41-49

occurrence of............................ 50

small proportion of...................... 43

utilization of............................ 50

Gastroliths, occurrence of.................... 18-19

Gebo dome, description of................. 136-137

developmentof.......................... 138

. position of..-..---....................... 42,43

structure of........................... 137-138

testing of................................ 55

George, R. H., acknowledgment to.......... 12

Gilmore, C. W., fossils determined by....... 28,30

Good & Dray ton, acknowledgment to....... 12

Gooseberry anticline, testing of.............. 55

Gooseberry dome and anticline, description of......................... 164-165

structure-contour map of................ 162

Grant, J. A., acknowledgment to............ 12

Grass Creek anticline, description of...... 151-152,

157-158 

development of........................ 155-157

drilling in............................... 55

log of well on............................ 154

structure of........................... 152-154

structure-contour map. of................ 160

Grass Creek field, productive area of......... 43

standard drilling rig in, plate showing... 152 

Greybull, use of gas in....................... 12

Greybull dome, drilling in................... 54

Page.

Greybull field, description of................ 58-59

development of.................... 62-64,66-67

productive area of....................... 43

quality of oil and gas in................. 64-66

structure of............................. 59-62

Greybull sand, oil and gas in................ 42

stratigraphic position of................. 19

H.

Half Moon anticline, compiled map of....... 178

description of..................... 178-179,180

structure of........................... 179-180

Hares, C. J., work of........................ 13

Harrison, T. L., acknowledgment to......... 12

J.

Jackson No. 7 well, log of.................... 78

Jurassic system, rocksof.................... 18

K. 

Kimball No. 2 well, log of................... 78

Kimball sand, oil from....................... 75,77

Knowlton, F. H., fossils determined by.. .19,27,28

L.

Lake Creek anticline, description of..... 125-126,127

structure-contour map of................ 12U

structure of............................ 126-127

Lamb, Homer T., acknowledgement to..... 12

Lamb anticline, description of............... 70-71

development of......................... 73-75

drilling in............................... 54

structure-contour map of................. 78

structure of.............................. 71-73

Lance formation, angular unconformity of, 

with Fort Union formation, plato 

showing......................... 26

nature of................................ 27-28

Lands, mineral, classification of............... 7-8

Lane No. 1 well, log of....................... 73

Levi, Kendrick, acknowledgment to....;.... 12

Levi, Nathan, acknowledgment to.......... 12

Levi No. 3 well, log of.......................1 14C

Little Buffalo Basin, description of........ 101,164

drilling in............................... 55

Little Grass Creek dome, description of..... 159-161

structure-contour map of................. 160

testing of................................ 55

Location of the Big Horn Basin................ 14

Lucerne anticline, description of.......... 136-137

development of.......................... 138

structure-contour map of................. 146

structure of........................... 137-138

testing of................................ 55

Lysite Mountain anticline, description of. 121-122,123 

Frontier formation in.................... 21

structure-contour map of.....:.......... 126

structure of............................ 122-123

M.

McFayden, John, acknowledgment to........ 12

McGrath, Martin, acknowledgment to........ 12

Madison limestone, nature of................. 17
INDEX. 191

Page. 

Madison limestone in Sheep Mountain canyon

plate showing................... 16

Mahogany Butte, plate showing............. 98

Mahogany Butte anticline, description of.. 119-120,

121 

structure-contour map of................. 120

structure of............................ 120-121

Manderson anticline, description of...... 86-57,89

structure-contour map of................ 98

structure of.............................. 87-89

Massey, Millard, work of..................... 13

Meade No. 1 wen, Greybull field, record of... 62 

Meeteetse formation, nature of............... 27

Mercer anticline, description of............... 83

development of.......................... 85-86

t structured.............................. 84-85

Mesaverde formation, escarpment of basal

sandstone of plate showing...... 183

natureof................................ 25-27

near Zimmerman Butte, plate showing.. 26 

outcrop of basal sandstone of, plate show-

* ing.............................. 182

Minor Well, Greybull field, record of......... 62

Moorcrof t oil field, position of................. 46

Morrison formation, gas in................... 41

natureof................................ 18-19

unconformable contact of, with Cloverly

formation, plate showing........ 20

Mowry shale, nature of....................... 20

near Bonanza, plate showing............. 20

oil and gasin............................. 41,42

" Muddy sand," stratigraphic position of.... 19-20

N. 

Neiber, log of well near....................... 141

Neiber anticline, description of........ 139-140,142

development of.......................... 141

position of............................... 33

structure-contour map of.........'........ 140

structure of............................ 140-141

testing of................................ 55

No Wood anticline, description of........ 97-98,100

structure-contour map of................. 98

structure of.............................. 98-99

west of No Wood Creek, plate showing .. 98 

No Wood Creek, Chugwater formation on,

plate showing................... 17

Embar formation near head of, plate

showing......................... 17

North Oregon Basin dome, structure-contour

map of.......................... 184

Northrup, J. D., work of.................... 13

0. 

Octh Louie sand,oil from.................... 75,77

Oil, analyses of................. 51-52,64-65,80,157

chemical character of.................... 50-52

mode of occurrence of.................... 41-49

nature of................................ 12

physical character of..................... 50-52

Oil thrown into air when well was shot, plate

showing......................... 78

Oregon Basin, description of....... 181-182,185-186

development of........................ 184-185

structure of............................ 182-184

Oregon basin domes, drilling in.............. 55

Orton, Edward, cited........................ 42

P. Page.

Paintrock anticline, description of........... 90

development of.......................... 92-93

structure-contour map of................ 98

structure of.............................. 91-92

Parks, E. M., work of....................... 13

Peay sandstone member, plate showing...... 21

stratigraphic position of................. 20

Peerless Oil Co., log of well drilled by, on

Spring Creek anticline........... 176

Petroleum. See Oil.

Pipelines, data on........................... 56

Pitchfork anticline, description of.......... 171,173

structure of............................ 171-173

R. 

Rainfall, average of.......................... 15

Red Spring anticline, description of.... 133-134,135

fault trace at east end of, plate showing.. 124 

structure-contour map of................ 134

structure of............................ 134-135

Refineries, data on.......................... 56

Ruth well, log of............................ 73

S.

Salt Creek field, position of.................. 45-46

Sand Draw anticline, description of.... 142-143,144

structure-contour map of................ 146

structure of............................ 143-144

Scope of this report ......................... 11-12

Scoville, Sam, acknowledgment to........... 12

Sheep Mountain, section of Frontier formation

on............................... 21

Sheep Mountain anticline, description of..... 56-57

Sheep Mountain canyon, Madison limestone

in, plate showing................ 16

Shell Creek dome, description of............. 67-69

development of.......................... 69-70

stnjcture-contour map of................ 68

testing of................................ 55

Sherard, Henry M., acknowledgment to..... 12

Sherard dome, description of.......... 105-106,108

development of........................ 107-108

drilling In............. ft ................. 55

structure of............................ 106-107

Shooting of well, plate showing.............. 78

Shoshone anticline, description of........... 186-188

drilling in............................... 54

Shoshone River, section of Frontier formation

on............................... 23

South Oregon Basin dome, structure-contour

map of.......................... 184

South Sunshine anticline, description of... 165-166 

structure-contour map of................ 166

structure of............................ 166-167

Spring Creek anticline, cross section of northwest end of, plate showing....... 152

description of.................. 174-175,176-177

structure-contour map of................ 176

structure of............................ 175-176

testingof.................. .............. 55

Stanton, T. W., fossils determined by....... 25

Stomach stones, occurrence of............... 18-19

Stratigraphy of the Big Horn Basin.......... 16-30

Structural terms, definitions of.............. 30-32

Structural terrace, definition of.............. 31

Structure-contour maps, construction and use

of................................ 37-41
192 INDEX.

Page. 

Structure of the Big Horn Basin............. 32-37

Sundance formation, nature of............... 18

Sunshine, section of Frontier formation near.. 23

Sunshine anticline, description of.. 165-166,167-168

structure-contour map of................ 166

structure of............................ 166-167

Sutherland, A. C., work of................... 13

Syncline, definition of....................... 30

T.

Tanberg, J. C., acknowledgment to....... 1.. 12

Taylor, W. E., acknowledgment to.......... 13

Temperature, range of....................... 15

Tensleep anticline, description of...... 112-113,115

structure-contour map of, plate showing. 114 

structure of........................... 113-115

Tensleep sandstone, nature of............... 17

on Brokenback anticline, plate showing. 16 

Tertiary system, formations of.............. 27-30

Thermopolis, section of Frontier formation

near............................. 22

Thermopolis anticline, description of...... 135-136

structure-contour map of................ 146

Thermopolis shale, nature of................ 19-20

near Bonanza, plate showing............ 20

oil and gas in............................ 41

Thickness of beds, differences in, on limbs T>f

an anticline..................... 34-36

Topography of the Big Horn Basin.......... 14

Torchlight dome, description of............. 75-76

development of....................... 78,80-81

drilling in............................... 54

movable drilling rig on, plate showing... 78 

shooting of well on, plate showing....... 78

structure-contour map of................ 78

structure of............................. 76-78

Torchlight field, productive area of.......... 43

Torchlight sandstone member, stratigraphic

place of......................... 20

Triassic system, rocks of..................... 18

U. 

Upfolds, productiveness of.................. 43-46

V.

Vegetation of the Big Horn Basin.

W.

Wagonhound anticline^ description of. 149-150,151 

development of........................ 150-151

log of well No. 1 on...................... 151

structure-contour map of................ 150

structure of............................. 150

testing of................................ 55

Walker, W. L., acknowledgment to......... 12

Wasatchformation, dip of................... 32-33

nature of................................ 29-30

Water, influence of.......................... 60

Water resources of the Big Horn Basin...... 15-16

See also the anticlines and domes. 

Waugh anticline, description of........ 144-145,147

development of........................ 146-147

drilling in............................... 55

structure-contour map of................ M6

structure of........................... 145-146

Well area, description of........... 108-109,111-112

mapof................................... 108

structure of........................... 109-111

Wells, data on......................... 63-64,74,79

West Buffalo anticline, description of..."... 101,164 

development of........................ 163-164

structure-contour map of................ 162

structure of........................... 161-463

White, David, introduction by............. 7-9

Whiting, F. X., acknowledgment to......... 12

, Wildhorse Butte anticline, description of. 127-128,

129 

structure-contour map of................ 134

structure of........................... 128-129

Wood, B. H., work of....................... 13

Wood River, section of Frontier formation on. 23 

valley of, description of.................. 166

Woodring, W. P.,workof................... 13

Woolery, M. D., acknowledgment to........ 12

Wyoming, economic reports on, list of...... 8-9

Z.

Zeisman dome, description of.......... 100-101,102

structure-contour map of................ 102

structure of............................ 101-102

Zimmerman Butte anticline, description of 131-132,

133 

structure-contour maps of............... 132

structure of........................... 132-133

C