Region
United States
460
Carbon County
169
Wyoming
120
Colorado
51
Utah
51
California
25
Pennsylvania
25
Emery County
23
Sweetwater County
22
Montana
19
China
16
Nevada
15
Alaska
13
Albany County
9
Florida
9
Texas
9
West Virginia
9
Louisiana
7
Mexico, Gulf of
7
Carbon County (Utah)
6
Idaho
6
Kentucky
6
Pacific Ocean
6
Australia
5
Bahamas
5
Carbon County (Wyo.)
5
Delta Region
5
Great Basin
5
Indian Ocean
5
Mexico
5
Middle West
5
North Dakota
5
Oregon
5
Stillwater County
5
Washington (State)
5
Arizona
4
Fort Union Formation
4
Fremont County
4
Great Plains
4
Illinois
4
New York (State)
4
Tennessee
4
Uintah County
4
Alabama
3
Book Cliffs (Utah and Colo.)
3
Brazoria County
3
Calcasieu Parish
3
Denver
3
Denver Metropolitan Area
3
Developing countries
3
more ...