Region
California
28
Nevada
15
Utah
8
San Francisco Bay Area
6
San Andreas Fault
5
Washington (State)
4
Arizona
2
Arkansas
2
California, Southern
2
Colorado
2
Hayward Fault (Calif.)
2
Idaho
2
Jefferson County
2
Missouri
2
Montana
2
New Madrid Region
2
Nye County
2
Salt Lake County
2
San Andreas Fault (Calif.)
2
San Joaquin Valley
2
West Virginia
2
Alameda County
1
Alaska
1
Arctic regions
1
Atlanta Region
1
Beaverhead County
1
Berkeley County
1
Bernalillo County
1
Blytheville Region
1
Cache County
1
Clark County
1
Cochise County
1
Contra Costa County
1
Crittenden County
1
Elko Region
1
Elko quadrangle
1
Elsinore Fault (Calif.)
1
Ely quadrangle
1
Fish Lake Watershed
1
Flathead Indian Reservation
1
Georgia
1
Glenn County
1
Goldfield quadrangle
1
Henrys Lake Region
1
Imperial County
1
Inyo County
1
Juab County
1
Kitsap County
1
Kittitas County
1
Lake County
1
more ...