Region
Montana
14
Black Hills (S.D. and Wyo.)
13
South Dakota
13
Colorado
11
Alaska
10
Missouri
8
Fall River County
7
Utah
7
Wyoming
7
Kentucky
6
New Jersey
6
Balochistan Region
5
New Mexico
5
Pakistan
5
United States
5
Kansas
4
Powder River Basin (Wyo. and Mont.)
4
San Juan County
4
Vermont
4
Wisconsin
4
Iowa
3
McLean County
3
Mexico
3
Michigan
3
Mississippi River Valley
3
New Madrid Region
3
New York (State)
3
Big Horn County
2
Bighorn Basin (Mont. and Wyo.)
2
British Columbia
2
California
2
Connecticut
2
Garfield County
2
Hopkins County
2
Illinois
2
Kane County
2
Massachusetts
2
Muhlenberg County
2
Nebraska
2
Nevada
2
New London County
2
North Atlantic Ocean
2
North Dakota
2
Oklahoma
2
Paradox Basin
2
Pennsylvania
2
Puget Sound Region
2
Rio Arriba County
2
Rio Blanco County
2
San Miguel County
2
more ...