California 68
Colorado 47
Alaska 32
Wyoming 31
Nevada 26
Utah 21
Arizona 16
North America 16
New Mexico 15
Washington (State) 14
Mexico 12
Baja California (Peninsula) 11
Montana 11
Panama 11
Piceance Creek Basin 11
Texas 11
United States 11
Canal Zone 10
Oregon 10
Puerto Rico 10
West (U.S.) 9
Southern States 8
Uinta Basin (Utah and Colo.) 8
Fremont County 6
Maryland 6
New Jersey 6
Olympic Peninsula 6
Virginia 6
Florida 5
Inyo County 5
Natrona County 5
San Joaquin Valley 5
Atlantic States 4
California, Southern 4
Coast Ranges 4
Japan 4
Kootznahoo Formation (Alaska) 4
Lincoln County 4
Mississippi Embayment 4
North Carolina 4
Nye County 4
San Juan Basin (N.M. and Colo.) 4
South Carolina 4
Cook Inlet Region 3
Georgia 3
Green River Formation 3
Mays Landing Region 3
North Slope 3
Okinawa-ken 3
Piceance Creek Basin (Colo.) 3
Powder River Watershed (Wyo. and Mont.) 3
San Andreas Fault (Calif.) 3
Santa Maria Basin 3
Teton County 3
Alabama 2
Atlantic Coast (U.S.) 2
Bighorn Basin (Mont. and Wyo.) 2
Book Cliffs Region (Utah and Colo.) 2
Borneo Region 2
Burke County 2
Caribbean Area 2
Carlin region 2
Carson City 2
Catron County 2
Churchill County 2
Clark County 2
Cook Inlet 2
Dakota Territory 2
Delaware 2
Elko Region 2
Fort Pillow Region 2
Front Range (Colo. and Wyo.) 2
Gallatin County 2
Grand Canyon Region 2
Grand County 2
Guam 2
Hillsborough County 2
Hopi Indian Reservation 2
Juab County 2
Kansas 2
Kent County 2
Kern County 2
Kodiak Island Region 2
Kootznahoo Formation 2
Kootznahoo Inlet Region 2
La Sal Mountains 2
Lander County 2
Los Angeles Region 2
Massachusetts 2
Middle Atlantic States 2
Midway Islands 2
Mineral County 2
Missouri 2
Navajo Indian Reservation 2
Nevada County 2
Nevada Test Site 2
New Madrid Region 2
New York (State) 2
North Dakota 2
Oceania 2