California 56
Nevada 17
Arizona 16
Utah 16
Alaska 13
Colorado 13
Idaho 13
New Mexico 10
Montana 9
North America 9
West (U.S.) 9
United States 8
Oregon 7
Washington (State) 6
San Joaquin Valley 5
Antarctica 4
Delmarva Peninsula 4
Islands of the Pacific 4
Monterey County 4
Northwest, Pacific 4
Texas 4
Coast Ranges 3
Massachusetts 3
Mojave Desert 3
Oceania 3
Rocky Mountains 3
Sacramento Valley 3
Sangre de Cristo Mountains (Colo. and N.M.) 3
Santa Maria Basin 3
Sierra Nevada (Calif. and Nev.) 3
South America 3
South Carolina 3
Wet Mountain Valley 3
Wyoming 3
Arctic regions 2
Atlantic Coast (U.S.) 2
Barstow Region 2
Blackfoot Region 2
Bonneville, Lake 2
California, Southern 2
China 2
Churchill County 2
Coast Range 2
Colorado Plateau 2
Colorado River Region (Colo.-Mexico) 2
Death Valley Region (Calif. and Nev.) 2
Feather River Region 2
Fisher Valley 2
Flagstaff Region 2
Fox Mountain (Nye County) 2
Fresno County 2
Granite Mountains 2
Grant County 2
Great Basin 2
Gulf Coast (U.S.) 2
Gulf States 2
Harney County 2
High Plains (U.S.) 2
Honcut Creek Region 2
Hopewell Region 2
Hopi Indian Reservation 2
Horry County 2
Iceland 2
Martha's Vineyard 2
Mediterranean Region 2
Merced River Valley 2
Mexico 2
Mid-Atlantic Bight 2
Midway Islands 2
Mississippi River Valley 2
Navajo Indian Reservation 2
Nebraska 2
New Jersey 2
North Carolina 2
North Dakota 2
Owyhee County 2
Richland County 2
Salinas River Valley 2
San Joaquin River Watershed 2
Santa Maria Basin (Calif.) 2
Santa Rita Mountains 2
Seaman Range 2
Searles Valley 2
Sespe Formation (Calif.) 2
Trans-Pecos (Tex. and N.M.) 2
Ventura Basin 2
Victoria Land 2
Virginia 2
Yuba River Region 2
Yucca Mountain Region 2
Adams County 1
Agate Fossil Beds National Monument 1
Agate Fossil Beds National Monument (Neb.) 1
Ajo Region 1
Alameda County 1
Alaska Range 1
Amargosa Desert (Nev. and Calif.) 1
America 1
Antarctic Ocean 1
Apache County 1