Region
California
18
Nevada
13
Utah
8
San Francisco Bay Area
5
Arkansas
2
Hayward Fault (Calif.)
2
Missouri
2
New Madrid Region
2
Salt Lake County
2
San Andreas Fault
2
San Andreas Fault (Calif.)
2
Washington (State)
2
Alameda County
1
Arctic regions
1
Arizona
1
Atlanta Region
1
Beaverhead County
1
Bernalillo County
1
Blytheville Region
1
Cache County
1
California, Southern
1
Colorado
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
Georgia
1
Goldfield quadrangle
1
Idaho
1
Imperial County
1
Inyo County
1
Juab County
1
Kitsap County
1
Las Vegas Region
1
Lemhi County
1
Los Angeles County
1
Los Angeles Region
1
Lovelock quadrangle
1
Lund quadrangle
1
Maryland
1
McDermitt quadrangle
1
Millett quadrangle
1
Mississippi River Valley
1
Mono County
1
Montana
1
Montgomery County
1
Nebraska
1
more ...