Region
United States
462
Carbon County
171
Wyoming
120
Utah
52
Colorado
51
California
25
Pennsylvania
25
Emery County
23
Sweetwater County
22
Montana
20
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
Carbon County (Wyo.)
6
Idaho
6
Kentucky
6
Pacific Ocean
6
Australia
5
Bahamas
5
Delta Region
5
Great Basin
5
Indian Ocean
5
Mexico
5
Middle West
5
North Dakota
5
Oregon
5
Stillwater County
5
Uintah 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
Alabama
3
Book Cliffs (Utah and Colo.)
3
Brazoria County
3
Calcasieu Parish
3
Denver
3
Denver Metropolitan Area
3
Developing countries
3
more ...