Vitrinite Reflectance Data for the Wind 

River Basin, Central Wyoming

By, Thomas M. Finn, Laura N.R. Roberts, and Mark J. Pawlewicz

Open-File Report 2006–1015

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

P. Patrick Leahy, Acting Director

U.S. Geological Survey, Reston, Virginia: 2006

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Suggested citation:

Finn, T.M., Roberts, L.N.R., and Pawlewicz, M.J., 2006, Vitrinite reflectance data for the Wind River Basin, central, 

Wyoming: U.S. Geological Survey Open-File Report 2006-1015.
iii

Contents

Introduction.....................................................................................................................................................1

References Cited............................................................................................................................................2

Figures

1. Map showing general outline of the Wind River Basin, central Wyoming.........................3

2. Generalized stratigraphic chart of Jurassic through lower Tertiary rocks in the Wind 

River Basin, central Wyoming ....................................................................................................4

Table

1. Vitrinite reflectance data and sample locations for the Wind River Basin,

central Wyoming...........................................................................................................................5
Introduction

The Wind River Basin is a large Laramide (Late Cretaceous through Eocene) structural and sedimentary basin that 

encompasses about 7,400 mi2 in central Wyoming (fig. 1). The 

basin boundaries are defined by fault-bounded Laramide uplifts 

that surround it, including the Owl Creek and Bighorn Mountains to the north, Wind River Range to the west, Granite Mountains to the south, and Casper Arch to the east (fig. 1). Important 

conventional oil and gas resources have been discovered and 

produced from reservoirs ranging in age from Cambrian through 

Tertiary (Keefer, 1969; Fox and Dolton, 1989, 1996; De Bruin, 

1993). In addition, an extensive overpressured basin-centered 

gas accumulation has also been identified in Cretaceous and 

Tertiary sandstone reservoirs by numerous researchers including 

Spencer (1987), Johnson and others (1996), Surdam (1997), and 

Surdam and others (1997, 2004). The purpose of this report is 

to present new vitrinite reflectance data to be used in support of 

the U.S Geological Survey assessment of undiscovered oil and 

gas resources of the Wind River Basin.

One hundred and nineteen samples were collected from 

Jurassic through Tertiary rocks, mostly coal-bearing strata 

(figs. 1, 2), in an effort to better understand and characterize 

the thermal maturation and burial history of potential source 

rocks. The results of the analyses are presented in table 1. 

One sample was from core and the remainder are from well 

cuttings. These data were collected and analyzed to supplement previously published data by Johnson and others (1991), 

Barker and Crysdale (1993); Barker and others (1993), Katz 

and Liro (1993), Nuccio and others (1993), Pawlewicz (1993), 

Nuccio (1994), and Nuccio and others (1996). 

The coal samples were analyzed by vitrinite reflectance 

to determine levels of thermal maturation. Preparation of the 

coal for reflectance analysis required (1) crushing the larger 

coal pieces into 0.25- to 1-millimeter pieces, (2) casting the 

pieces with epoxy in pre-cut and drilled plugs, and (3) curing 

the samples overnight. Subsequently, a four-step grinding 

process was implemented − two with progressively finer sandpaper (60 and 600 grit), and two polishing steps (0.3 and 0.05 

micron). Vitrinite reflectance measurements were determined 

at 500 X magnification using plane-polarized incident white 

light and a 546-nanometer monochromatic filter in immersion 

oil. For samples with sufficient quality vitrinite, at least 25 

measurements were recorded. For samples of poorer quality, 

either due to a poor polish or to the presence of mineral or 

other inorganic material, fewer measurements were recorded. 

Vitrinite Reflectance Data for the Wind River Basin, 

Central Wyoming

By Thomas M. Finn, Laura N.R. Roberts, and Mark J. Pawlewicz
References Cited

Barker, C.E., and Crysdale, B.L., 1993, Burial and temperature 

history of gas generation from coaly organic matter in the 

Late Cretaceous Mesaverde Formation and associated rocks 

in the deeper portions of the Wind River Basin, Wyoming, 

in Stroock, Betty, and Andrew, Sam, eds., Jubilee Anniversary Field Conference: Wyoming Geological Association, 

Casper, Wyoming, p. 233-258. 

Barker, C.E., Bartck, T.D., Hatcher, P.G., and Daws, T.A., 

1993, An empirical correlation between coal bed gas with 

Rock-Eval pyrolysis and 13C NMR results, Cretaceous 

Mesaverde and Meeteetse Formation, Wind River Basin, 

Wyoming: in Keefer, W.R., Metzger, W.J., and Godwin, 

L.H., eds., Oil and gas and other resources of the Wind 

River Basin, Wyoming: Wyoming Geological Association 

Special Symposium, 1993, Casper, Wyoming, p. 243-256. 

De Bruin, R.H., 1993, Overview of oil and gas geology of 

Wyoming, in Snoke, A.W., Steidtmann, J.R., and Roberts, 

S.M., eds., Geology of Wyoming: Geological Survey of 

Wyoming Memoir No. 5, p. 836-873. 

Fox, J.E., and Dolton, G.L., 1989, Petroleum geology of the 

Wind River and Bighorn Basins, Wyoming and Montana: 

U.S. Geological Survey Open-File Report 87-450P, 41 p.

Fox, J.E., and Dolton, G.L., 1996, Wind River Basin Province; 

in Gautier, D.L., Dolton, G.L., Takahashi, K.I., and Varnes, 

K.L., eds., 1995 National assessment of United States oil 

and gas resources-results, methodology, and supporting 

data: U.S. Geological Survey Digital Data Series DDS-30, 

release 2.

Johnson, R.C., Barker, C.E., Pawlewicz, M.J., Crysdale, B.L., 

Clark, A.C., and Rice, D.D., 1991, Preliminary results of 

coalbed methane assessment of the Wind River Indian Reservation, Wyoming: in Schwochow, S.D., Murray, D,K., and 

Fahy, M.F., eds., Coalbed methane of western North America, 

Rocky Mountain Association of Geologists, p. 273-284.

Johnson, R.C., Finn, T.M., Crovelli, R.A., and Balay, R.H., 

1996, An assessment of in-place gas resources in low-permeability Upper Cretaceous and Lower Tertiary sandstone 

reservoirs, Wind River Basin, Wyoming: U.S. Geological 

Survey Open-File Report 96-264, 58 p.

Katz, B.J., and Liro, L.M., 1993, The Waltman Shale Member, 

Fort Union Formation, Wind River Basin: A Paleocene clastic lacustrine source system: in Keefer, W.R., Metzger, W.J., 

and Godwin, L.H., eds., Oil and gas and other resources

of the Wind River Basin, Wyoming: Wyoming Geological 

Association Special Symposium, 1993, Casper, Wyoming, 

p. 163-174.

Keefer, W.R., 1969, Geology of petroleum in Wind River 

Basin, central Wyoming: American Association of Petroleum Geologists Bulletin, v. 53, no. 9, p. 1839-1865. 

Nuccio, V. F., 1994, Vitrinite reflectance data for the Paleocene Fort Union and Eocene Wind River Formations, and 

burial history of a drill hole located in central Wind River 

Basin, Wyoming: U.S. Geological Survey Open-File Report 

94-220, 43 p. 

Nuccio, V.F., Finn, T.M., and Pawlewicz, M.J., 1993, Surface 

vitrinite reflectance study of the Wind River Basin, central 

Wyoming: in Keefer, W.R., Metzger, W.J., and Godwin, 

L.H., eds., Oil and gas and other resources of the Wind 

River Basin, Wyoming: Wyoming Geological Association 

Special Symposium, 1993, Casper, Wyoming, p. 307-317. 

Nuccio, V.F., Finn, T.M., and Johnson, R.C., 1996, Thermal 

maturity data for the assessment of gas resources in the 

Wind River Basin, Wyoming: U.S. Geological Survey 

Open-File Report 96-064, 57 p.

Pawlewicz, M.J., 1993, Vitrinite reflectance and geothermal gradients in the Wind River Basin: in Keefer, W.R., 

Metzger, W.J., and Godwin, L.H., eds., Oil and gas and 

other resources of the Wind River Basin, Wyoming: Wyoming Geological Association Special Symposium, 1993, 

Casper, Wyoming, p. 295-306.

Spencer, C.W., 1987, Hydrocarbon generation as a mechanism 

for overpressuring in Rocky Mountain basins: American 

Association of Petroleum Geologists Bulletin, v. 71, no. 4, 

p. 368-388.

Surdam, R.C., 1997, A new paradigm for gas exploration in 

anomalously pressured “Tight Gas Sands” in the Rocky 

Mountain Laramide basins, in Surdam, R.C., ed., Seals, 

traps, and the petroleum system: American Association of 

Petroleum Geologists Memoir 67, p. 283-298.

Surdam, R.C., Jiao, Z.S., and Heasler, H.P., 1997, Anomalously pressured gas compartments in Cretaceous rocks of 

the Laramide basins of Wyoming: A new class of hydrocarbon accumulation, in Surdam, R.C., ed., Seals, traps, and 

the petroleum system: American Association of Petroleum 

Geologists Memoir 67, p. 199-222.

Surdam, R.C., Jiao, Z.S., and Ganshin, Y., 2004, Reducing the 

risk of exploring for anomalously pressured gas assets: Gas 

Technology Institute, Gas Tips, v. 10, no. 1, 5 p.

 Vitrinite Reflectance Data for the Wind River Basin, Wyoming
MT

ID WY

0 15 30 MILES

WYOMING

110° W

43° N

44° N

109° W 108° W 107° W















 4

5

6

7

8

2

3

1

Granite Mountains

Bighorn Mountains Owl Creek Mountains

Wind River Range

Figure 1. Map showing general outline of the Wind River Basin, central Wyoming, and locations of samples for vitrinite reflectance analysis. N1 in table 1. 
Figure 2. Generalized 

stratigraphic chart of Jurassic 

through lower Tertiary rocks in 

the Wind River Basin, central 

Wyoming. Inset map shows 

locations of samples for 

vitrinite reflectance analysis; 

numbers refer to column 1 in 

table 1.

Shotgun

Member

Unnamed middle member

Parkman Sandstone Member

Fales Sandstone Member

Wallace Creek Tongue of Cody Shale

PALEOCENE LATE 

Western Wind River Basin Eastern Wind River Basin Southern and central

Wind River Basin

Lance

Formation

Teapot Sandstone Member

Cody Shale Cody Shale Cody Shale

Lance

Formation

Lance

Formation

Meeteetse Formation

Meeteetse Formation Meeteetse

Formation

Teapot Sandstone Member Teapot Sandstone Member Mesaverde Formation

Mesaverde Formation

Mesaverde Formation

lower part

lower part

Fort Union FormationFort Union Formation

Fort Union Formation

CRETACEOUS TERTIARY (part)

EOCENE

 (part)

Wind River and 

Indian Meadows Formations

undivided

Wind River and 

Indian Meadows Formations

undivided

Wind River and 

Indian Meadows Formations

undivided

Mowry Shale

Frontier Formation

JURASSIC

(part)

EARLY 

Muddy Sandstone

Thermopolis Shale

Morrison Formation

Cloverly Formation

Frontier Formation Frontier Formation

Waltman Shale

Member

Waltman Shale

Member

Shotgun

Member

Shotgun

Member

Lower member Lower member Lower member

and

Lewis Shale undivided

Waltman Shale

Member

System Series

Southern and

central Wind 

River Basin

Eastern

Wind

River Basin

















 4

5

6 7

8

2

3

9

1

Western Wind 

River Basin

 Vitrinite Reflectance Data for the Wind River Basin, Wyoming
Table 1. Vitrinite reflectance data and sample locations for the Wind River Basin; central Wyoming

[All data are from well cuttings except for sample at Map no. 6, which is from core. Map no. refers to numbers plotted in figure 1. Depth range, in feet. Abbreviations: API, well number assigned by AmTN, Township North; RW, Range West; Sec., section; Ro, vitrinite reflectance; N, number of readings per sample; Std. dev., standard deviation; Fm, Formation; Mbr, Member; Lith., lithology; carb sh, car

Map no. API TN RW Sec. Operator Well Depth range %Ro N Std. dev. Formation or Member Lith. 

1 49013209380000 4 2 11 Husky Oil Tribal 16-11 3330-3340 0.52 30 0.04 Mesaverde Fm coal

49013209380000 4 2 11 Husky Oil Tribal 16-11 3620-3630 0.46 29 0.02 Mesaverde Fm coal49013209380000 4 2 11 Husky Oil Tribal 16-11 3910-3920 0.50 35 0.06 Mesaverde Fm coal49013209380000 4 2 11 Husky Oil Tribal 16-11 4220-4270 0.52 25 0.04 Cody Shale coal49013209380000 4 2 11 Husky Oil Tribal 16-11 4670-4690 0.59 23 0.06 Cody Shale coal po49013209380000 4 2 11 Husky Oil Tribal 16-11 5020-5070 0.56 25 0.05 Cody Shale coal49013209380000 4 2 11 Husky Oil Tribal 16-11 8990-9030 0.53 20 0.09 Frontier Fm coal49013209380000 4 2 11 Husky Oil Tribal 16-11 10020-10110 0.39 8 0.13 Frontier Fm/Mowry Shale coal few 49013209380000 4 2 11 Husky Oil Tribal 16-11 10390-10420 0.40 18 0.09 Muddy Sandstone coal pro

2 49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 4300-4360 0.58 19 0.01 Fort Union Fm coal

49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 4900-5000 0.59 21 0.03 Fort Union Fm coal49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 5520-5600 0.59 17 0.04 Fort Union Fm coal49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 5920-6000 0.62 23 0.03 Fort Union Fm coal49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 6360-6400 0.59 23 0.03 Fort Union Fm coal low 49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 7560-7620 0.68 15 0.03 Lance Fm coal low 49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 7660-7760 0.69 21 0.04 Lance Fm coal mi49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 7860-7960 0.79 18 0.02 Lance Fm coal mi49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 8640-8680 0.63 19 0.04 Mesaverde Fm coal mi49013205650000 36 94 25 Pancanadian Pet. Co. Fuller Reservoir II 22-25 9200-9300 0.75 25 0.03 Cody Shale coal

3 49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 1090-1210 0.46 2 0.00 Fort Union Fm coal on

49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 1520-1550 0.47 27 0.04 Fort Union Fm coal49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 2000-2090 0.45 19 0.04 Fort Union Fm coal po49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 3270-3330 0.48 27 0.04 Lance Fm coal fai49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 4140-4230 0.56 21 0.04 Lance Fm coal fai49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 5000-5030 0.57 27 0.05 Meeteetse Fm coal49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 6020-6110 0.55 21 0.04 Mesaverde Fm coal fai49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 7120-7240 0.59 31 0.04 Cody Shale coal fai49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 8620-8680 0.56 13 0.04 Cody Shale coal fai49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 10900-10950 0.56 13 0.06 Cody Shale coal po49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 11050-11120 0.80 13 0.30 Frontier Fm coal po49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 11700-11800 0.54 17 0.03 Muddy Sandstone coal on49025209780000 35 88 27 Diamond Shamrock 1-27 Coal Bank 12170-12180 0.58 11 0.05 Thermopolis Shale coal po

4 49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 2080-2200 0.44 4 0.04 Shotgun Mbr carb sh po

49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 2470-2530 0.47 17 0.05 Shotgun Mbr coal fai49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 2620-2830 0.67 9 0.12 Shotgun Mbr coal po49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 5020-5060 0.54 25 0.05 Lower Fort Union coal fai49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 6800-6870 0.64 14 0.05 Lower Fort Union coal fai49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 7900-7930 0.67 29 0.06 Lance Fm coal49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 8820-8910 0.70 25 0.08 Lance Fm coal fai49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 9900-10000 0.53 25 0.02 Lance Fm coal49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 11260-11280 0.74 31 0.05 Lance Fm coal49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 11400-11450 0.68 27 0.04 Lance Fm coal fai

49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 11600-11620 0.82 29 0.05 Lance Fm coal49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 11760-11780 0.73 25 0.05 Lance Fm coal49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 11910-11930 0.72 31 0.05 Meeteetse Fm coal fai49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 12140-12180 0.72 19 0.05 Meeteetse Fm coal fai49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 12430-12460 0.61 31 0.05 Meeteetse Fm coal49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 12660-12740 0.60 29 0.05 Meeteetse Fm/Teapot Sandstone coal49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 12820-12890 0.66 27 0.05 Mesaverde Fm coal fai49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 13110-13150 0.66 5 0.02 Mesaverde Fm carb sh po49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 13300-13350 0.57 13 0.05 Mesaverde Fm carb sh litt49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 13650-13740 0.73 17 0.06 Mesaverde Fm coal49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 14870-14930 0.89 3 0.06 Cody Shale carb sh litt49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 16300-16450 1.25 16 0.26 Cody Shale shale wh49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 18520-18560 1.21 2 0.05 Frontier Fm coal on49025208370000 35 86 11 Union Oil of Calif. Hells Half Acre 1-K-II 19650-19700 1.40 2 0.04 Muddy Sandstone coal
Table 1. Vitrinite reflectance data and sample locations for the Wind River Basin; central Wyoming.-Continued

Map no. API TN RW Sec. Operator Well Depth range %Ro N Std. dev. Formation or Member Lith. 

5 49025058080000 34 85 30 True Oil 1 Sun Ranch 3400-3520 0.45 23 0.05 Fort Union Fm coal

49025058080000 34 85 30 True Oil 1 Sun Ranch 3820-4000 0.50 31 0.03 Fort Union Fm coal49025058080000 34 85 30 True Oil 1 Sun Ranch 5620-5720 0.43 10 0.10 Lance Fm coal49025058080000 34 85 30 True Oil 1 Sun Ranch 6990-7040 0.56 31 0.06 Lance Fm coal49025058080000 34 85 30 True Oil 1 Sun Ranch 7290-7370 0.63 33 0.04 Lance Fm coal49025058080000 34 85 30 True Oil 1 Sun Ranch 7720-7780 0.67 25 0.06 Meeteetse Fm coal49025058080000 34 85 30 True Oil 1 Sun Ranch 8070-8110 0.64 15 0.06 Meeteetse Fm coal lea49025058080000 34 85 30 True Oil 1 Sun Ranch 8500-8550 0.64 31 0.03 Mesaverde Fm coal49025058080000 34 85 30 True Oil 1 Sun Ranch 8600-8630 0.59 31 0.03 Mesaverde Fm coal49025058080000 34 85 30 True Oil 1 Sun Ranch 8970-9020 0.54 33 0.04 Fales Sandstone Mbr coal

6 49025220540000 33 86 23 Diamond Shamrock 23-23 N. Grieve 10269 0.52 33 0.02 Muddy Sandstone coal cor7 49025200590000 33 84 11 Union Oil WPS Unit 8 5840-6310 0.58 33 0.07 Fort Union Fm coal

49025200590000 33 84 11 Union Oil WPS Unit 8 6970-7240 0.57 35 0.05 Lance Fm coal49025200590000 33 84 11 Union Oil WPS Unit 8 7710-7770 0.62 13 0.05 Lance Fm coal po49025200590000 33 84 11 Union Oil WPS Unit 8 7830-7890 0.61 33 0.04 Lance Fm coal49025200590000 33 84 11 Union Oil WPS Unit 8 8120-8160 0.67 31 0.04 Lance Fm coal49025200590000 33 84 11 Union Oil WPS Unit 8 8490-8520 0.59 31 0.05 Meeteetse Fm coal49025200590000 33 84 11 Union Oil WPS Unit 8 9030-9100 0.53 29 0.05 Meeteetse Fm coal49025200590000 33 84 11 Union Oil WPS Unit 8 9260-9300 0.58 31 0.06 Mesaverde Fm coal49025200590000 33 84 11 Union Oil WPS Unit 8 9600-9660 0.60 31 0.04 Mesaverde Fm coal49025200590000 33 84 11 Union Oil WPS Unit 8 10190-10240 0.59 29 0.04 Cody Shale coal49025200590000 33 84 11 Union Oil WPS Unit 8 10390-10440 0.60 29 0.08 Cody Shale coal49025200590000 33 84 11 Union Oil WPS Unit 8 11030-11090 0.68 25 0.04 Cody Shale coal49025200590000 33 84 11 Union Oil WPS Unit 8 11900-11950 0.59 37 0.06 Cody Shale coal49025200590000 33 84 11 Union Oil WPS Unit 8 12710-12760 0.59 23 0.06 Cody Shale coal/shale49025200590000 33 84 11 Union Oil WPS Unit 8 12970-13040 0.52 33 0.03 Cody Shale coal/shale49025200590000 33 84 11 Union Oil WPS Unit 8 14130-14280 0.62 8 0.09 Cody Shale/Frontier Fm coal ver49025200590000 33 84 11 Union Oil WPS Unit 8 15340-15400 1.25 5 0.04 Muddy Sandstone/Thermopolis Shale coal/shale sha

8 49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 1240-1270 0.34 25 0.02 (?) coal

49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 1690-1720 0.37 31 0.03 (?) coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 2530-2560 0.46 27 0.04 Lance Fm coal ox49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 3010-3040 0.43 31 0.03 Meeteetse Fm coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 3640-3670 0.45 29 0.06 Teapot Sandstone Mbr coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 4090-4120 0.45 29 0.03 Middle Mbr Mesaverde Fm coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 4600-4630 0.44 31 0.04 Fales Sandstone Mbr coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 5290-5320 0.43 29 0.05 Cody Shale coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 6040-6160 0.46 31 0.05 Cody Shale coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 7190-7280 0.42 25 0.03 Cody Shale coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 7970-8080 0.42 27 0.06 Cody Shale coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 10440-10450 0.43 31 0.04 Frontier Fm coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 10750-10790 0.44 31 0.04 Frontier Fm coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 11530-11600 0.61 25 0.04 Muddy Sandstone (?) coal49025211460000 32 84 20 Elf Aquitaine 21-20 Grayrock Federal 11760-11800 0.73 23 0.26 Cloverly Fm coal mi
Table 1. Vitrinite reflectance (Ro) data and sample locations for the Wind River Basin; central Wyoming.-Continued

Map no. API TN RW Sec. Operator Well Depth range %Ro N Std. dev. Formation or Member Lith. 

9 49025204400000 32 83 34 Union Oil 1-34 Young Ranch 3640-3720 0.49 3 0.12 Fort Union Fm coal ver

49025204400000 32 83 34 Union Oil 1-34 Young Ranch 4100-4160 0.43 4 0.05 Fort Union Fm coal lea49025204400000 32 83 34 Union Oil 1-34 Young Ranch 42804360 0.41 15 0.04 Fort Union Fm coal low 49025204400000 32 83 34 Union Oil 1-34 Young Ranch 4710-4740 0.49 19 0.05 Lance Fm coal low 49025204400000 32 83 34 Union Oil 1-34 Young Ranch 5400-5420 0.52 27 0.05 Lance Fm coal low 49025204400000 32 83 34 Union Oil 1-34 Young Ranch 5810-5820 0.55 41 0.03 Meeteetse Fm coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 6070-6080 0.73 17 0.16 Meeteetse Fm coal low 49025204400000 32 83 34 Union Oil 1-34 Young Ranch 6350-6370 0.56 8 0.03 Meeteetse Fm/Lewis Shale coal low 49025204400000 32 83 34 Union Oil 1-34 Young Ranch 6650-6680 0.47 9 0.05 Mesaverde Fm coal low 49025204400000 32 83 34 Union Oil 1-34 Young Ranch 6800-6830 0.58 29 0.05 Mesaverde Fm coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 7120-7130 0.48 25 0.03 Mesaverde Fm/Cody Shale coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 7450-7470 0.51 27 0.05 Fales Sandstone Mbr coal low 49025204400000 32 83 34 Union Oil 1-34 Young Ranch 7820-7860 0.51 21 0.07 Cody Shale coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 8110-8150 0.45 13 0.04 Cody Shale coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 9100-9130 0.46 21 0.04 Cody Shale coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 9800-9860 0.48 29 0.05 Cody Shale coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 10740-10800 0.48 25 0.04 Cody Shale coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 11750-11830 0.51 31 0.06 Frontier Fm coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 12870-12900 0.48 31 0.04 Muddy Sandstone coal49025204400000 32 83 34 Union Oil 1-34 Young Ranch 13250-13380 1.15 11 0.14 Morrison Fm coal ob