Petroleum Potential of 

Wilderness Lands in 

Wyoming

By Charles W. Spencer

With a section on The Wyoming part of the WyomingUtah-Idaho Thrust Belt, by Richard B. Powers

PETROLEUM POTENTIAL OF WILDERNESS LANDS IN THE 

WESTERN UNITED STATES

GEOLOGICAL SURVEY CIRCULAR 902-M

This chapter on the petroleum 

geology and resource potential of 

Wilderness Lands in Wyoming is 

also provided as an accompanying 

pamphlet for Miscellaneous Investigations Series Map 1-1547

CONTENTS

Abstract Ml

Methods of evaluation 2

Petroleum province potentials 5

Southwestern Wyoming Basins province 5 

Wyoming part of the Wyoming-Utah-Idaho Overthrust Belt province , by Richard B.

Powers 6

Wind River Basin province 7

Bighorn Basin province 7

Powder River Basin province 8

References cited

ILLUSTRATIONS

Page

FIGURE 1. Map of Wyoming showing selected basins and uplifts, Wilderness Lands, and oil and gas potentials for the Wilderness Lands M2

2. Map of Wyoming showing USGS petroleum provinces (Dolton and others 1981, p. 75), Wilderness Lands, and

the ott and gas potentials for the Wilderness Lands 3

3. Map of Wyoming showing location of Wilderness Lands and oil and gas fields 4

III

PETROLEUM POTENTIAL OF WILDERNESS LANDS IN THE WESTERN UNITED STATES

Petroleum Potential of Wilderness Lands in Wyoming

By Charles W. Spencer

ABSTRACT

A comprehensive review of the geology of 6,006,903 acres 

has been made to assess the petroleum potential of the Wilderness Lands in Wyoming. The potential for oil and gas accumulations in Wilderness Lands in Wyoming ranges from high to 

zero. Lands with high potential are located mostly within 

sedimentary basins where thick sequences of good reservoir 

rocks and hydrocarbon source beds are present. High potential 

tracts are also present in the Wyoming Thrust belt in western 

Wyoming. Areas with zero oil and gas potential are located 

mostly on mountain uplifts where Precambrian igneous and 

metamorphic rocks are exposed. A large portion of Yellowstone National Park lands has unknown potential owing to 

a thick cover of Tertiary and Quaternary volcanic and volcaniclastic rocks and sediments.

The petroleum potential for Wilderness Lands in Wyoming 

can be summarized by acreage as follows: high potential, 661.8 

thousand acres; medium potential, 391.8 thousand acres; low 

potential, 723.3 thousand acres; low to zero potential, 19.0 

thousand acres; zero potential, 1,759.3 thousand acres; and unknown potential, 2,451.8 thousand acres.

INTRODUCTION

An assessment has been made of the oil and gas 

potential of Wilderness Lands in Wyoming. The 

types of Wilderness Lands are shown on a map of 

Wyoming prepared by the U.S. Bureau of Land 

Management (1981). These Wyoming Wilderness 

Lands include: USFS Designated Wilderness, 

USFS and NFS Administratively Endorsed as 

Suitable (prior to 1981), BLM and USFS Further

Planning or Study Areas, and BLM Lands Under 

Appeal.

The tectonic elements of Wyoming and other 

Rocky Mountain States are identified and discussed by Grose (1972). The oil and ga* map of 

Wyoming by VerPloeg and others (1980) shows a 

structure contour map of Wyoming. The general 

surface geology of the State is shown by Love and 

others (1955). The structure and stratigraphy of 

Wyoming and other Rocky Mountain S'ates are 

discussed in Mallory (1972).

The State of Wyoming is a structurally complex 

area consisting of low to high mountain uplifts 

with adjacent basins. Selected uplifts and basins 

are shown in figure 1. Some of the major basins 

are the northern Denver basin in the southeast, 

the Powder River basin in the northeast, the 

Green River, Washakie, and Great DivMe basins 

in the southwest, the Wind River bas'n in the 

west-central, and the Bighorn basin in tV northwest part of the State. The Wyoming Tl ~ust belt 

is present on the west and southwest nargin of 

the State. As shown in figure 1, most of these 

large basins and other smaller basins are separated by major uplifts or arches. The cores of 

many of the uplifts are Precambrian igr^ous and 

metamorphic rocks. Some of the wilderness and 

wilderness study areas are located on exposed 

Precambrian rocks and therefore have ze~o oil and

Ml
YELLOWSTONEABSAROKA

VOLCANIC 

AREA

SO

I

100 MILES

FIGURE 1.

O 5O 1OO KILOMETERS

-Map of Wyoming showing selected basins and uplifts, Wilderness Lands, and the oil and gas potentials for the Wilderness Lands.

gas potential. However, in some Wyoming 

localities Precambrian rocks are thrust over prospective sediments; consequently, some Precambrian outcrop areas have oil and gas potential 

(Gries, 1983). The Yellowstone-Absaroka Tertiary 

and Quaternary volcanic area is present in the 

northwest corner of Wyoming.

Figure 1 shows the location and qualitative oil 

and gas potential of the Wilderness Lands in 

Wyoming and selected basins and uplifts. These 

boundaries are denned on geologic features and 

are slightly different from the USGS petroleum 

province boundaries shown in figure 2 which were 

used by Dolton and others (1981) and generally 

follow along county lines in Wyoming.

Through 1981, oil and gas fields in Wyoming had 

produced 4,944 million barrels of oil and 9,002 billion cubic feet of gas (Wyoming O'1 and Gas Conservation Commis., 1981). Most of the oil and gas 

was produced from reservoirs of Mississippian, 

Pennsylvanian, Permian, Triassic, Jurassic, Cretaceous, and Tertiary age. The location of Wyoming basins, oil and gas fields, ancf the age of producing formations are shown in VerPloeg and 

others (1980). Figure 3 is a m?^ of Wyoming 

showing the location of oil and gas fields.

METHODS OF EVALUATION

This evaluation is based on botv published and 

unpublished data and takes into consideration the 

distribution and types of oil and gr<* accumulations 

in both producing and abandoned fields. The analysis is primarily based on the known or interpreM2
ted distribution of reservoir rocks and hydrocarbon source beds, geologic history, and stratigraphic and structural style favorable for oil and 

gas accumulations in Wyoming and adjacent 

States.

Hydrocarbon accumulations require four critical 

factors: (1) reservoir (porous) rocks, (2) hydrocarbon (organic-rich) source beds, (3) a relatively impermeable seal or barrier to prevent upward and 

(or) lateral migration of hydrocarbons, and (4) 

favorable thermal history. It is a generally accepted fact that temperature and time are required to thermochemically alter organic material 

(kerogen) and yield oil and (or) gas. Shallow, lowtemperature gas of biologic origin is not believed 

to have any significant resource potential within 

any of the Wyoming Wilderness Lands.

Two main types of hydrocarbon traps exist: (1) 

structural traps, usually related to tector;<» movement and include, but are not limited to, folds 

(anticlines) and faults or combinations of folds and 

faults; and (2) stratigraphic traps, thc-^e traps 

formed by an updip change of porous sandstone or 

carbonate into relatively impermeable rocks. In 

many fields the hydrocarbon trap is a combination 

of both structure and stratigraphy.

The relative ratings of hydrocarbon potential 

used in this evaluation are as follows:

High potential. Geologic environmen* highly 

favorable for occurrence of oil and gas ^"cumulations. Area is within or on trend with existing 

production from structural and (or) stratigraphic 

traps.

110

50 10O MILES 

_J

10O KILOMETERS

FIGURE 2. Map of Wyoming showing USGS petroleum provinces (Dolton and others 1981, p. 75), Wilderness Lands and the

oil and gas potentials for the Wilderness Lands.

M3
11O'

1OO MILES

I 

so 100 KILOMETERS

FIGURE 3. Map of Wyoming showing location of Wilderness Lands (outlined) and oil and gas fields (shown in black) from VerPloeg and others (1980). Some additional fields are posted from recent drilling data. Not all new fields are shown.

Medium potential. Geologic environment favorable for the occurrence of oil and gas accumulations. Contains known reservoir rocks and hydrocarbon source beds. Includes some areas of sparse 

subsurface control or areas where expected field 

size will be small.

Low potential. Geologic environment interpreted 

to have low potential for the occurrence of oil and 

gas accumulations. Includes areas of poor or unknown hydrocarbon source bed and (or) reservoir 

quality. Generally includes areas of sparse or with 

no well control and (or) expected thin sequence of 

sedimentary rocks.

Zero potential. Areas generally with exposed 

Precambrian rocks or with very thin sedimentary

section with no potential for occurrence of sealed 

structural or stratigraphic traps with hydrocarbons.

Unknown potential. Generally includes areas 

with no well control where Tertiary volcanic intrusions and volcaniclastic rocks are present on the 

surface. This cover, plus lack of subsurface control, makes prediction of hydrocarbon potential 

extremely difficult. Includes sone areas where 

Precambrian igneous and metanmrphic rocks are 

thrust over Phanerozoic (Cambrian and younger) 

sedimentary rocks of unknown potential. Lack of 

subsurface control does not mear that no oil and 

gas potential exists, but only that the hydrocarbon 

potential cannot reasonably be determined with 

present data.

M4
PETROLEUM PROVINCE 

POTENTIALS

Figure 2 shows resource province names and

-umdaries as used in Dolton and others (1981). 

"le boundaries of these provinces are placed 

^ ostly along county lines and do not exactly agree 

Mth the basins and uplifts shown in figure 1 which 

 e placed along geologic boundaries.

SOUTHWESTERN WYOMING BASINS 

PROVINCE

The Southwestern Wyoming Basins province is 

£ major oil and gas producing region. Skeeters 

s nd Hale (1972) summarized the petroleum geology of this province. Oil and gas are produced 

f ~om both structural and stratigraphic traps. Cretnceous and Tertiary sandstones are the major 

1 reducing reservoirs, but production has also been 

established from Cambrian sandstone, Mississip- 

] ;an carbonate rocks, Pennsylvanian carbonate 

rocks and sandstone, and Jurassic sandstone.

This province includes the Laramie, Medicine 

Fow, and Sierra Madre uplifts (fig. 1). Wilderness 

Lands on these uplifts are in areas of exposed 

] recambrian rocks and have zero oil and gas potential. However, unpublished data and data from 

Gries (1983) indicate that the Precambrian rocks 

; long the west flank of the Sierra Madre uplift 

(ng. 1) are thrust an unknown distance westward 

rnd southwestward over Paleozoic and Triassic 

sedimentary rocks. This thrust, however, is not 

sufficiently denned to indicate that the Sierra 

Madre tracts have any potential.

Two tracts along the southwest flank of the 

iVeetwater (Granite Mountains) uplift (fig. 1) are 

rnown as having unknown potential. The EmiI Trant Trail thrust bounds the southwest and west 

:"ank of the northwest part of this uplift (Gries, 

983). Wells drilled through the Emigrant Trail 

'hrust have confirmed the presence of Precambrian rocks thrusted over Paleozoic and Mesozoic 

rudimentary rocks (Gries, 1983). This thrust trend 

probably continues southeastward and forms the 

north edge of the Hanna basin (Gries, 1983, fig. 

'). The presence of sedimentary rocks with petro- 

<nim potential beneath the tracts rated as un- 

~nown cannot presently be determined. Other 

' Tacts on the Sweetwater uplift have zero potenial because they are in areas of exposed Precamb-

*ian rocks which are probably not thrust over 

^edimentary rocks with petroleum potential.

The Greater Green River basin in Wyoming 

consists of three basins or subbasinr the 

Washakie basin, the Great Divide basin (Red Desert basin of oil industry usage), and the Green 

River basin proper. The Green River brsin is 

bounded on the west by the Wyoming Thrurt belt.

Tracts in the Green River basin prope~ have 

high potential for gas accumulations in s+.ratigraphic and structural traps in Cretaceous 

sandstone. However, there is low potential for 

structurally controlled oil and gas accumulations 

in Jurassic sandstone and Permian and Penrsylvanian sandstones and carbonates. Tracts in the 

Washakie basin have high potential for gas in Cretaceous sandstone and low potential for oil in 

Paleozoic reservoirs. Tracts in the Great Divide 

basin have high potential for gas and some oil in 

stratigraphic traps in Cretaceous and TMiary 

sandstone. A small portion of Bureau of Land 

Management tract 040-323 lies within the Wind 

River Basin province of Dolton and others (1981) 

and all of tract 040-325 lies within the Wine1 River 

Basin province. Geologically these tracts ar^ within the Great Divide basin. These tracts have high 

and medium potential for hydrocarbon accumulations in stratigraphic traps in front of and beneath 

the thrust that bounds the southwest flank of the 

Wind River uplift (Gries, 1983). The best potential 

is for gas accumulations in Cretaceous and Tertiary sandstone stratigraphic traps. To the northwest, a few tracts on the southwest flank of the 

Wind River uplift have unknown potential I iscause 

the presence of potentially oil and gas productive 

rocks beneath the thrust cannot be determined. 

Most of the Wilderness Lands on the uplift have 

zero potential because they are in areas of exposed Precambrian rocks and (or) thin Prleozoic 

rocks that have not been thrust over sediir«ntary 

rocks with petroleum potential.

The Gros Ventre Wilderness area is located adjacent to the extreme northwest corner of the 

Green River basin (fig. 1) and is partly within the 

Wyoming Thrust belt. Simons and others (1980) 

studied the geology and mineral potential of the 

Gros Ventre Wilderness Study Area in considerable detail. They concluded that the southwest 

flank of the Gros Ventre Wilderness (uplift) is 

bounded by the Cache Creek thrust fault and that 

this thrust had moved from north and nortl ?ast to 

south and southwest and had overridden petroleum potential Paleozoic and Mesozoic rock:". They 

noted that hydrocarbon accumulations nay be 

present in structural and stratigraphic traps in

M5
front of (southwest of) the Cache Creek thrust as 

well as in structural and stratigraphic traps beneath the thrust (Simons and others, 1980, p. 57). 

They also note that several wells in the area have 

reported oil and gas "shows." The area adjacent to 

and in front of the Cache Creek fault is rated in 

the present study as having high oil and gas potential. The area north and east of the fault, on 

the main part of the uplift, has some structurally 

high exposures of Precambrian and Cambrian 

rocks as well as extensive outcrops of Permian 

and older sedimentary rocks. This area was rated 

as having low to zero potential. The potential is 

downgraded because of the absence of a good reservoir sealing cover of Mesozoic rocks and because of structurally high exposures of Precambrian and Lower Paleozoic rocks.

The Southwestern Wyoming Basins province 

(fig. 2) extends northward into the YellowstoneAbsaroka Tertiary and Quaternary volcanic area 

and to the Montana-Wyoming border in Yellowstone National Park. The Gros Ventre Wilderness borders the northwest end of the Green 

River basin proper (fig. 1) and forms the south 

edge of a geologic transition area that includes the 

Teton uplift, Washakie uplift, and Jackson Hole 

(Grose, 1972). Love and others (1973) summarize 

the geology of the Teton region and show a threedimensional diagram of the area. Wilderness 

Lands on the Teton uplift have zero potential 

owing to the presence of extensive exposures of 

Precambrian igneous and metamorphic rocks and 

Paleozoic carbonate rocks, sandstone, and shale 

(Love and others, 1955; Love and others, 1973). 

The northernmost part of this area of zero potential does have some exposures of rocks ranging in 

age from Paleozoic to Quaternary, but any reservoirs in these rocks are probably flushed with 

freshwater.

The area rated as having low potential, located 

northeast of the Wilderness Lands on the Teton 

uplift (fig. 1), has potential for gas production 

from structural and stratigraphic traps in Cretaceous and Tertiary sandstone and coal beds. Most of 

these lands lie within the Jackson Hole coal field 

as shown in Hausel and others (1979) and as described by Jones (1982). Coal beds are one of the 

principal sources of natural gas. Love and others 

(1975) have studied the geology and mineral resources of the Teton Corridor which is located in 

the western part of the area of low potential. 

They noted that the potential of the Teton Corridor was difficult to determine owing to lack o: 

drilling. However, adequate g^s and oil source 

beds are present in Paleozoic and Cretaceous 

rocks (Love and others, 1975, p. A15). They alsc 

reported that a flammable gas seep is present ir 

the Teton Corridor.

Most of the land east of and north of the area 

of low potential within and adj^ent to the Teton 

Corridor is rated as having unknown potential. 

Much of the land rated as having unknown potential lies within Yellowstone National Park. These 

lands have unknown potential because they are 

mostly in areas where a thick cover of Tertiary 

and Quaternary igneous and volcaniclastic rocks 

and sediments obscure the underlying structure 

and stratigraphy of any potentially productive 

older rocks. Some exposures of Precambrian, 

Paleozoic, and Mesozoic rocks rre present in the 

area of unknown potential. The presence of hydrocarbon source beds and reservoir rocks in most oi 

the area having unknown potential cannot be determined. A few hot water springs in and adjacent 

to Yellowstone National Park have, historically, 

yielded small amounts of oil and (or) gas (Love 

and Good, 1970; Love and Good, 1982). These surface shows indicate the presence of subsurface hydrocarbon source beds that ha^e been contacted 

by thermal waters and do not irean that free hydrocarbons exist in reservoirs, The areas with 

zero potential are about centered in Yellowstone 

National Park and are the approximate site of a 

very large caldera formed by a volcanic eruption 

during the Quaternary Period (Reefer, 1971, fig. 

22). It is unlikely that this cakkra has any oil and 

gas potential.

WYOMING PART CT THE

WYOMING-UTAH-IDAHO

OVERTHRUST BELT PROVINCE

By RICHARD B. PO^VERS

The Wyoming-Utah-Idaho Ov^rthrust Belt province straddles parts of Wyoming, Utah, and 

Idaho (Dolton and others, 1981) and covers a total 

area of 15,000 square miles (39,000 km2). The 

Wyoming part of the province r the approximate 

eastern half of the thrust belt. T^ eastern boundary of the Wyoming thrust bel*: (fig.l) is marked 

by the surface trace of the Darl ^-Prospect thrusl 

plate, which separates the structurally deformed 

thrust belt from the Green Riv«*r basin in southwestern Wyoming.

M6
The thrust belt is the newest oil and gas producing province in the State of Wyoming. Production was first established in 1975 at the Pineview 

field in adjacent Summit County, Utah, and the 

initial discovery in the Wyoming part of the thrust 

belt was in July, 1976. The petroleum geology and 

resource potential of this province is summarized 

by Monley (1971), Royse and others (1975), Powers (1977; 1982; and chapter N, this circular).

Eighteen fields were discovered between 1975 

and mid-1983 in the southern Wyoming part of the 

thrust belt, and four additional new-field wildcat 

gas discoveries were recently announced in the 

central part of the Wyoming thrust belt. All oil 

and gas production in the Wyoming thrust belt 

comes from anticlinal structures in the hanging 

walls of thrust plates. The main producing reservoirs are of Jurassic and Mississippian age from 

both sandstone and carbonate rocks, with additional producing reservoirs of Cretaceous, Triassic, Permian, Pennsylvania!!, Devonian, and Ordovician age.

Four wilderness tracts with high oil and gas potential are located in the central and northwest 

parts of the thrust belt on trend with producing 

fields in various thrust plates. Two of the tracts 

are directly adjacent to new-field wildcat gas discovery wells. The same formations, similar reservoir and petroleum source rocks, and trapping 

structures, as well as a favorable thermal-maturation history, are interpreted to be present under 

these tracts in a framework similar to that in the 

highly productive southern part of the thrust belt.

WIND RIVER BASIN PROVINCE

The Wind River basin is a prolific producer of 

oil and gas from Paleozoic sandstone and carbonates, Mesozoic sandstone, and Tertiary 

sandstone. Benner (1972) noted that most of the 

oil and gas occurs in structural traps and that 

stratigraphic traps will become important producers in the future. This basin has very high potential for deep-basin gas production from Tertiary 

and Cretaceous conventional and low-permeability 

(unconventional) sandstone stratigraphic traps. 

Wilderness Lands with no potential in the westcentral, south, and southeast parts of this province are in areas where Precambrian igneous and 

metamorphic rocks are exposed on various uplifts 

flanking the basin. A small tract on the Owl Creek 

uplift (fig. 1) has low potential. This tract is in an

area of exposed lower Paleozoic rocks (Love and 

others, 1955). The south flank of the Owl Creek 

uplift is thrust from north to south over the north 

edge of the Wind River basin (Gries, 1983, fig. 1). 

This tract has potential for oil and gas in subthrust Mesozoic and Paleozoic rocks. The best potential is for structural and stratigraphic traps in 

Tertiary and Cretaceous sandstones beneath the 

thrust. Older reservoirs could contain som* hydrocarbons.

Wilderness Lands with low and medium potential are located in the northwest part of tve Wind 

River Basin province (fig. 2). Most of the^e lands 

are in areas of Tertiary cover but a few erix>sures 

of older sedimentary rocks are present (Love and 

others, 1955). It is interpreted that Mesozoic and 

Paleozoic rocks with petroleum potential are present throughout much of the area (Ketner and 

others, 1966; Prostka and others, 1979).

BIGHORN BASIN PROVINCE

The Big Horn Basin province of Dofton and 

others (1981) shown in figure 2 covers considerably more area than the Bighorn basin structural 

boundaries as shown in figure 1. The nanm of this 

basin is variously spelled Big Horn and Bighorn. 

The generally accepted spelling is Bighorn and is 

used in the following discussion.

The Bighorn basin of Wyoming and adjacent 

Montana is one of the most prolific oil and gas basins in the Rocky Mountain region. The petroleum 

geology of this basin is summarized by Weldon 

(1972). Much of the oil and gas production comes 

from structural traps located around the margins 

of the basin. The primary producing reservoirs 

are Mississippian carbonate rocks, Penns;Tlvanian 

sandstone, Permian carbonate rocks, and Cretaceous sandstone. The deep part of the basil is relatively unexplored by drilling but probfbly has 

been extensively mapped by seismic methods.

Wilderness Lands on the western side of this 

province (fig. 2) mostly lie beneath a thick Tertiary volcanic and volcaniclastic cover (Nelson and 

others, 1980; Love and others, 1955). These lands 

have been evaluated for their relative oil and gas 

potential by Spencer and Dersch (1981). The potential ranges from high for lands on trend with, 

and near existing fields, to unknown in areas of 

thick Tertiary volcanic cover. The high potential 

areas are on trend with, and adjacent to, known 

oil fields that produce from Paleozoic carbonates

M7
and sandstone. The presence of Paleozoic and 

Mesozoic rocks with petroleum potential can be 

predicted on the basis of limited outcrops and on 

well control adjacent to these areas. Areas where 

the presence of Paleozoic and (or) Mesozoic rocks 

can reasonably be predicted are rated as medium 

potential. The low potential areas include lands 

where favorable source beds and reservoir rocks 

are probably present. The unknown potential 

areas are remote from well or outcrop control and 

the presence of sedimentary rocks with petroleum 

potential cannot be predicted. An area with zero 

potential is situated on the northwestern edge of 

the Wyoming part of the province. This area of 

zero potential has extensive exposures of Precambrian rocks.

Lands in the center of the basin have high potential for gas and some oil in Cretaceous and Tertiary sandstone stratigraphic traps. These lands 

are located in and near the deepest part of the 

Bighorn basin. The deep part of the basin is only 

sparsely drilled, but stratigraphic conditions here 

are similar to those that exist in the deep basin 

gas areas of the Wind River, Great Divide, 

Washakie, and Green River basins. It is anticipated that extensive sequences of low-permeability (unconventional) gas reservoirs will be present 

in Tertiary and Cretaceous sandstones in addition 

to conventional reservoirs. Permian carbonates 

and Pennsylvanian sandstone and carbonate reservoirs also have some hydrocarbon potential.

A tract with medium potential is present south 

of the high potential tracts. This tract has slightly 

lower potential because the southern part of the 

basin is shallower and there are less potentially oil 

and gas bearing Tertiary sandstones present in 

the area. East of this tract is a wilderness tract 

with medium to low potential. This tract is located 

in the southeast part of the basin in an area where 

there are many oil and gas fields. These fields are 

shown in VerPloeg and others (1980). The production from these fields is dominantly oil and associated gas. Permian limestones are the major 

producing reservoirs and they produce from both 

stratigraphic and structural-stratigraphic traps. 

Pennsylvanian sandstone also is productive in 

many fields. Some production has been found in 

Cretaceous sandstones in this part of the basin.

Wilderness Lands on the east side of the province (fig. 2) are located on the west flank of the 

Bighorn uplift (fig. 1). These lands have zero potential because of extensive exposures of Precambrian rocks. Some tracts on the west side of 

this cluster of Wilderness LarHs are in areas 

where Pennsylvanian and older rocks crop out 

(Lowry and others, 1976). These tracts are interpreted to have zero potential, even though 

sedimentary rocks are present, because of flushing 

by meteoric (fresh) water and lacv of strong structural closures that might have th-> ability to facilitate the formation of hydrodyramically tilted oil 

accumulations.

POWDER RIVER BASIN PROVINCE

The Powder River basin (fig. 1) is a major oil 

producing basin with cumulative production exceeding 1 billion barrels of oil (I'cGregor, 1972). 

The basin extends northward into southeastern 

Montana but most of the oil and gas fields are in 

Wyoming. McGregor (1972) describes the general 

petroleum geology of the basin. Most of the oil 

(and associated gas) is produced f'om Permian and 

Pennsylvanian sandstone and doSmite, and Cretaceous sandstone reservoirs. In the past 20 years 

most of the new oil accumulations have been found 

in stratigraphic traps. The shallow eastern parts 

of the basin are extensively drilled but there is 

only sparse drilling in the deeper parts of the 

basin to the west. The tract in the geographical 

center of the basin, which has hijrh potential, is in 

an area of sparse drilling and hrs high potential 

for oil and gas in Cretaceous srndstone stratigraphic traps. There are many oil fields (VerPloeg 

and others, 1980) updip to the east which produce 

from Cretaceous sandstone and PennsylvanianPermian sandstone and dolomite.

Lands on the east side of the Bighorn uplift (fig. 

1) have low potential. These low potential tracts 

are in an area of exposed Precpmbrian igneous 

and metamorphic rocks and some steeply dipping 

Paleozoic and younger rocks. The east flank of the 

Bighorn uplift is interpreted to be thrust from 

west to east over the west side of the Powder 

River basin (Gries, 1983, fig. 1). Therefore, there 

is some potential for oil and gas ir Cretaceous and 

older rocks beneath the overthnrt. Data are not 

available to permit determination of the horizontal 

extent of overthrusting but it is probably about 

two to four miles (3-6 km).

Several low potential tracts on the west side of 

the province (fig. 2) are on the south plunge of the 

Bighorn uplift (fig. 1). These tracts are in an area 

where Mississippian carbonates and Pennsylvanian and Permian carbonates am? sandstone crop

M8
xut. There are also some local exposures of Or- 

'ovician and Cambrian rocks cropping out in areas

near these tracts so the oil and gas potential is

probably quite low.

SUMMARY

Of the 6,006,903 acres included in this study for 

1 he assessment of the petroleum potential of the 

1 Vilderness Lands in Wyoming, a summary of the 

potential follows: high potential, 661.8 thousand 

rsres; medium potential, 391.8 thousand acres; 

Hw potential, 723.3 thousand acres; low to zero 

potential, 19 thousand acres; zero potential, 

,759.3 thousand acres, and unknown potential, 

£,451.8 thousand acres. The petroleum potential 

1 y acreage of all Wilderness Land categories in 

i he Western United States is shown in this circular by B. M. Miller in table 1, chapter P.

REFERENCES CITED

"»enner, R. W., 1972, The Wind River basin, in Mallory, W. 

W., ed., Geologic atlas of the Rocky Mountain region: 

Rocky Mountain Association of Geologists, p. 273-274.

">olton, G. L., Carlson, K. H., Charpentier, R. R., Coury, A. 

B., Crovelli, R. A., Frezon, S. E., Khan, A. S., Lister, J. 

H., McMullin, R. H., Pike, R. S., Powers, R. B., Scott, 

E. W., and Varnes, K. L., 1981, Estimates of undiscovered recoverable conventional resources of oil and gas in 

the United States: U.S. Geological Survey Circular 860, 87

P-

"Sries, Robbie, 1983, Oil and gas prospecting beneath Precambrian of foreland thrust plates in Rocky Mountains: American Association of Petroleum Geologists Bulletin, v. 67, 

no. 1, p. 1-28.

^Jrose, L. T., 1972, Tectonics, in Mallory, W. W., ed., Geologic 

atlas of the Rocky Mountain Region: Rocky Mountain Association of Geologists, p. 35-44.

Tausel, W. D., Glass, G. B., Langeson, D. R., VerPloeg, A. 

J., and DeBruin, R. H., 1979, Wyoming mines and minerals: Wyoming Geological Survey, scale 1:500,000.

Tones, R. W., 1982, The Jackson Hole coal field, in Geology of 

Yellowstone Park area, 33rd Annual Field Conference 

Guidebook: Wyoming Geological Association, p. 315-321.

l"eefer, W. R., 1971, The geologic story of Yellowstone National Park: U.S. Geological Survey Bulletin 1347, 92 p.

Tetner, K. B., Reefer, W. R., Fisher, F. S., Smith, D. L., and 

Raabe, R. G., 1966, Mineral resources of the Stratified 

Primitive Area, Wyoming: U.S. Geological Survey Bulletin 1230-E, 56 p.

Love, J. D., Antweiler, J. C., and Williams, F. E., 1975, Mineral resources of the Teton Corridor, Teton County, 

Wyoming: U.S. Geological Survey Bulletin 1397-A, 51 p.

Love, J. D., and Good, J. M., 1970, Hydrocarbons in thermal 

areas, northwestern Wyoming: U.S. Geological Survey 

Professional Paper 644-B, 23 p.

 1982, Hydrocarbons in thermal areas, northwestern 

Wyoming, in Geology of Yellowstone Park area, 33rd Annual Field Conference: Wyoming Geological Association, 

p. 265-288.

Love, J. D., Reed, J. C., Jr., Christiansen, R. L., and Stacy, 

J. R., 1973, Geologic block diagram and tectonic 1 Hory of 

the Teton region, Wyoming-Idaho: U.S. Geologicr' Survey 

Miscellaneous Geologic Investigations Map 1-730.

Love, J. D., Weitz, J. L., and Hose, R. K., 1955, Geologic map 

of Wyoming: U.S. Geological Survey, scale 1:500,000.

Lowery, M. E. Lowham, H. W., and Lines, G. C., 1976, 

Water resources of the Bighorn basin, northwestern 

Wyoming: U.S. Geological Survey Hydrologic I^vestigations Atlas HA-512, 4 sheets.

Mallory, W. W., ed., 1972, Geologic atlas of the Rocky Mountain region: Rocky Mountain Association of Geologists, 331

PMcGregor, A. A., 1972, The Powder River basin, in Mallory, 

W. W., ed., Geologic atlas of the Rocky Mountan region: 

Rocky Mountain Association of Geologists, p. 268-270.

Monley, L. E., 1971, Petroleum potential of the Idah^-Wyoming Overthrust Belt, in Future petroleum provinces of the 

United States their geology and potential: American Association of Petroleum Geologists Memoir 15, v. 1, p. 509- 

537.

Nelson, W. H., Prostka, H. J., and Williams, F. P., 1980, 

Geology and mineral resources of the North Absamka Wilderness and vicinity, Park County, Wyomure U.S. 

Geological Survey Bulletin, 1447,101 p.

Powers, R. B., 1977, Assessment of oil and gas resources in 

the Idaho-Wyoming Thrust Belt, in Rocky fountain 

thrust belt geology and resources, 29th Annual F^'d Conference Guidebook: Wyoming Geological Association, p. 

629-638.

 , ed., 1982, Geologic studies of the Cordilleran Thrust 

Belt: Rocky Mountain Association of Geologists, 976 p.

Prostka, H. J., Antweiler, J. C., and Bieniewski, C. L., 1979, 

Mineral resources of the Du Noir Addition, Wash^kie Wilderness, Fremont County, Wyoming: U.S. Geolof'cal Survey Bulletin 1472, 35 p.

Royse, Frank, Jr., Warner, M. A., and Reese, D. L., 1975, 

Thrust belt structural geometry and related straMgraphic 

problems, Wyoming-Idaho-Northern Utah, in Bofyard, D. 

W., ed., Symposium on deep drilling frontiers in the central Rocky Mountains: Rocky Mountain Association of 

Geologists, p. 41-54.

Simons, F. S., Love, J. D., Keefer, W. R., Harwood, D. S., 

and Bieniewski, C. L., 1980, Mineral Resource" of the 

Gros Ventre Wilderness Study Area, Teton and Sublette 

Counties, Wyoming: U.S. Geological Survey Cien-File 

Report 80-510, 94 p.

Skeeters, W. W., and Hale, L. A., 1972, Southern V'yoming, 

in Mallory, W. W., ed., Geologic atlas of the rocl*^ Mountain region: Rocky Mountain Association of Geolo<rists, p. 

274-276.

Spencer, C. W., and Dersch, J. S., 1981, Map showing evaluation of oil and gas potential of the Shoshone National 

Forest, Wyoming: U.S. Geological Survey Open-File Report 81-667, scale 1:500,000.

U.S. Bureau of Land Management, 1981, State of Wyoming 

wilderness status map: U.S. Bureau of Land Management, 

scale 1:1,000,000.

M9
VerPloeg, A. J., DeBruin, R. H., and Langeson, D. R., 1980, Mountain Association of Geologists, p. 270-272.

Oil and gas map of Wyoming: Geological Survey of Wyom- Wyoming Oil and Gas Conservation Commission, 1981, Wy

ing, Map Series 6, scale 1:500,000. ing oil and gas statistics, 1981: Wyoming Oil and Gas O

Weldon, J. P., 1972, The Big Horn basin, in Mallory, W. W., servation Commission, 123 p. 

ed., Geologic atlas of the Rocky Mountain region: Rocky

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