Region
Wyoming
Sweetwater County
13
Johnson County
10
Carbon County
9
Fremont County
8
Natrona County
8
Campbell County
6
Utah
6
Colorado
5
Crook County
3
Caribou County
2
Granite Mountains
2
Idaho
2
Lincoln County
2
Niobrara County
2
Powder River Basin (Wyo. and Mont.)
2
Pumpkin Buttes
2
Rich County
2
Shirley Basin
2
South Dakota
2
Wind River Basin
2
Browns Park Formation
1
Converse County
1
Great Divide Basin
1
Green River Watershed
1
Lusk
1
Lusk Region
1
Medicine Bow Mountains (Colo. and Wyo.)
1
Moffat County
1
New Mexico
1
North Dakota
1
Red Desert
1
Red Desert Region
1
West (U.S.)
1
Wind River Watershed
1