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