National Assessment of Oil and Gas Fact Sheet

Assessment of Undiscovered

Oil and Gas Resources of the

Wind River Basin Province, 2005

Introduction

The U.S. Geological Survey (USGS) recently completed an 

assessment of the undiscovered oil and gas potential of the Wind 

River Basin Province (fig. 1), which encompasses about 4.7 million acres in central Wyoming. The assessment is based on the 

geologic elements of each total petroleum system (TPS) defined 

in the province, including hydrocarbon source rocks (source-rock 

maturation, hydrocarbon generation, and migration), reservoir 

rocks (sequence stratigraphy and petrophysical properties), and 

hydrocarbon traps (trap formation and timing). Using this geologic framework, the USGS defined three TPSs: (1) Phosphoria TPS, 

(2) Cretaceous-Tertiary TPS, and (3) Waltman TPS. Within these 

systems, 12 Assessment Units (AU) were defined and undiscovered oil and gas resources were quantitatively estimated within 10 

of the 12 AUs (table 1).

Using a geology-based assessment methodology, 

the U.S. Geological Survey estimated a mean of 2.4 

trillion cubic feet of undiscovered natural gas, a mean 

of 41 million barrels of undiscovered oil, and a mean of 

20.5 million barrels of undiscovered natural gas liquids 

in the Wind River Basin Province of Wyoming.

Resource Summary

The USGS assessed both undiscovered conventional 

oil and gas and undiscovered continuous (unconventional) 

oil and gas in the Wind River Basin Province, resulting in estimated means of 2.4 trillion cubic feet of gas 

(TCFG), 41 million barrels of oil (MMBO), and 20.5 

million barrels of total natural gas liquids (MMBNGL) 

for the three TPSs. The majority of the undiscovered gas 

resource, 81 percent or 1.9 TCFG, is interpreted as continuous and is contained within the Cretaceous-Tertiary 

TPS. The continuous gas is contained within seven AUs 

of the Cretaceous-Tertiary TPS; mean estimates include: 

Frontier-Muddy Continuous Gas AU (0.48 TCFG), Cody 

Sandstone Continuous Gas AU (0.12 TCFG), MesaverdeMeeteetse Sandstone Gas AU (0.38 TCFG), Lance-Fort 

Figure 1. Wind River Basin Province located in central Wyoming.

Wind River

Indian Reservation

Sweetwater 

River

Boysen 

Reservoir

Pathfinder

Reservoir

Bull Lake

Ocean

 Lake

Green River

Wind 

River

North

Platte

Powder

River

Carbon 

Natrona

Washakie Johnson Hot Springs

Fremont

Sublette

Park

Teton

25

Thermopolis

Pinedale

Riverton

Lander

Casper

Jeffrey 

City

Kaycee

Dubois

MT

ID WY

WYOMING 0 15 30 Miles

Major thrust 

faults–sawteeth

on upper fault plate

110° 

43° 

44° 109° 108° 107° 

Fish Creek

Basin

 thrust

GRANITE

 MOUNTAINS 

BIGHORN

 MOUNTAINS 

Casper 

Powder

River

Basin

Bighorn Basin

OWL CREEK MOUNTAINS

WIND

RIVER

 MOUNTAINS Wind

River 

arch

26

287

189 191

287

220

20

26

20

U.S. Department of the Interior

U.S. Geological Survey

USGS Fact Sheet FS-2005-3141

December 2005 Printed on recycled paper
Union Sandstone Gas AU (0.71 TCFG), Mesaverde Coalbed 

Gas AU (0.11 TCFG), Meeteetse Coalbed Gas AU (0.02 

TCFG), and Fort Union Coalbed Gas AU (0.12 TCFG) (table 

1). The remainder of the undiscovered gas is associated/

dissolved gas in oil accumulations (0.08 TCFG) or is in conventional nonassociated gas accumulations (0.37 TCFG) in 

the Tensleep-Park City, Cretaceous-Tertiary, and Upper Fort 

Union Sandstones Conventional Oil and Gas AUs (table 1).

For Further Information

Supporting geologic studies of total petroleum systems 

and assessment units, and reports on the methodology used in 

the Wind River Basin Province assessment, are in progress. 

Assessment results are available at the USGS Central Energy 

Team website: http://energy.cr.usgs.gov/oilgas/noga/

Wind River Basin Province Assessment Team

Mark A. Kirschbaum (Task Leader; mkirsch@usgs.gov), Thomas M. Finn, Ronald C. Johnson, Joyce Kibler, Paul G. Lillis, 

Philip H. Nelson, Laura N.R. Roberts, Stephen B. Roberts, Ronald R. Charpentier, Troy Cook, Timothy R. Klett, Richard M. 

Pollastro, and Christopher J. Schenk.

4 16 42 18 4 15 44 19 90 360 1,090 440

0.00 0.00 0.00 0.00 56 244 600 275 1,040 4,710 12,550 5,490

3 10 23 11

3 25 12

10 35 84 40 230 820 2,130 950

30 92 190 99 230 720 1,620 790

6 21 54 24 330 1,250 3,370 1,470

8.80 58.20 164.60 0 0 0 0 0 0 0 0

10 41 106 407 972 457 1,920 7,860 20,760 9,140

66.90 100.50 151.00 103.60 198 430 934 481 110 320 970 400

10 37 90 41 885 1,767 3,562 1,936 3,240 9,280 26,570 11,400

10 37 90 41 991 2,174 4,534 2,393 5,160 17,140 47,330 20,540

To Total undiscovered resources tal Petroleum Systems 

(TPS) 

and Assessment Units (AU)

Field

type

Oil (MMBO) Gas (BCFG) NGL (MBNGL)

Gas

Oil

Gas

Oil

Oil

Oil

Gas

Oil

Gas

Conventional Oil and Gas Resources Continuous Oil and Gas Resources

Total Continuous

Resources

 Phosphoria TPS

Total Conventional

Resources

Tensleep-Park City Conventional

Oil and Gas AU

Cretaceous-Tertiary TPS

Cretaceous-Tertiary TPS

Waltman Shale TPS

Waltman ShaleTPS

Cretaceous-Tertiary Conventional 

Oil and Gas AU

Upper Fort Union Sandstones

Conventional Oil and Gas AU

Waltman Fractured Shale 

Continuous Oil AU

Frontier-Muddy

Continuous Gas AU

Gas 66.90 100.50 151.00 103.60 48 103 224 115 10 30 10 40 Cody Sandstone

Continuous Gas AU

Cody Fractured Shale

Continuous Oil AU

Gas 66.90 100.50 151.00 103.60 163 345 732 383 360 960 2,580 1,150 Mesaverde-Meeteetse

Sandstone Gas AU

Gas 66.90 100.50 151.00 103.60 373 668 1,198 711 2,670 7,700 22,250 9,480 Lance-Fort Union

Sandstone Gas AU

CBG 66.90 100.50 151.00 103.60 45 96 205 107 70 210 570 250 Mesaverde

Coalbed Gas AU

CBG 66.90 100.50 151.00 103.60 9 19 41 21 10 40 120 50 Meeteetse

Coalbed Gas AU

CBG 49 106 228 118 10 20 70 30 Fort Union 

Coalbed Gas AU

Total Undiscovered

Oil and Gas Resources

Not quantitatively assessed

Not quantitatively assessed

37 90

11

Table 1. Wind River Basin Province assessment results.

[MMBO, million barrels of oil; BCFG, billion cubic feet of gas; MBNGL, thousand barrels of natural gas liquids; CBG, coal-bed gas.

Results shown are fully risked estimates. For gas fields, all liquids are included under the NGL (natural gas liquids) category. 

F95 represents a 95-percent chance of at least the amount tabulated. Other fractiles are defined similarly. Fractiles are additive 

under the assumption of perfect positive correlation. Gray shade indicates not applicable]