Region
Nevada
72
California
65
Colorado
48
Alaska
43
Montana
37
Earth (Planet)
35
Utah
30
Arizona
29
Vermont
24
New Mexico
21
West (U.S.)
21
Black Hills (S.D. and Wyo.)
20
Wyoming
20
United States
18
Washington (State)
17
New Hampshire
16
South Dakota
16
Appalachian Basin
15
Earth
15
Missouri
15
Virginia
15
Michigan
14
North America
14
Wisconsin
14
Mexico
13
Idaho
12
Kentucky
12
California, Southern
11
Massachusetts
11
New York (State)
11
Windsor County
11
Kansas
10
Piceance Creek Basin
10
Northwest, Pacific
9
Colorado Plateau
8
Illinois
8
Middle West
8
Nevada Test Site
8
New Madrid Region
8
New Madrid Seismic Zone
8
Oregon
8
South Carolina
8
Appalachian Mountains
7
Appalachian Region
7
Connecticut
7
Fall River County
7
Pakistan
7
Powder River Basin (Wyo. and Mont.)
7
Rhode Island
7
Southwest, New
7
more ...