Region
California
14
Nevada
9
Alaska
8
Arizona
8
Colorado
8
Montana
8
New Hampshire
6
New Madrid Seismic Zone
6
Rhode Island
6
Vermont
5
Grafton County
4
Michigan
4
New Mexico
4
New York (State)
4
Piceance Creek Basin
4
Virginia
4
Washington (State)
4
Wisconsin
4
Appalachian Basin
3
Atlantic Coast
3
Black Hills (S.D. and Wyo.)
3
Sullivan County
3
Uinta Basin (Utah and Colo.)
3
United States
3
West (U.S.)
3
Windsor County
3
Caledonia County
2
California, Northern
2
California, Southern
2
Canada
2
Essex County
2
Florida
2
Georgia
2
Idaho
2
Illinois
2
Kent County
2
Maine
2
Maryland
2
Middle West
2
Missouri
2
Mojave Desert
2
Newport County
2
Ohio
2
Pennsylvania
2
Piceance Creek Basin (Colo.)
2
San Pedro River Watershed (Mexico and Ariz.)
2
South Carolina
2
Utah
2
Washington County
2
Afghanistan
1
more ...