Region
Utah
Wyoming
Colorado
12
Idaho
6
Lincoln County
2
Montana
2
Nevada
2
Alaska
1
Arizona
1
Caribou County
1
Colorado Plateau
1
Colorado River (Colo.-Mexico)
1
Daggett County
1
Green River Formation
1
Green River Valley (Wyo.-Utah)
1
Moffat County
1
Mojave Desert
1
New Mexico
1
North Dakota
1
Rich County
1
South Dakota
1
Summit County
1
Sweetwater County
1
Uinta County
1
Uinta Mountains Region (Utah and Wyo.)
1