Texas 35 Idaho 27 New Mexico 27 Phosphoria Formation 26 Montana 19 Utah 19 Wyoming 18 Colorado 16 Kansas 10 Alaska 9 California 8 Oklahoma 8 Cutler Formation 5 United States 5 Antarctica 4 Arizona 4 Brown County 4 Coleman County 4 Manzano Mountains 4 Baylor County 3 China 3 Maroon Formation (Colo.) 3 Nevada 3 Pakistan 3 Pennsylvania 3 Powder River Basin (Wyo. and Mont.) 3 Powder River Watershed (Wyo. and Mont.) 3 West (U.S.) 3 White Rim Sandstone (Utah) 3 Afton Region 2 Alaska Range 2 Argus Range Region 2 Bernalillo County 2 Brazos River Valley 2 Butte County 2 Canyonlands National Park 2 Caribou County 2 Central Oklahoma Aquifer (Okla.) 2 Chinle Formation 2 Cutler Group 2 Eagle County 2 East Tintic Mountains 2 Glass Mountains 2 Great Basin 2 Greece 2 Guadalupe Mountains National Park 2 Guadalupe Mountains National Park (Tex.) 2 Hydra Island 2 Inyo Mountains 2 Kent County 2 Lisbon Valley 2 Mesaverde Group 2 Permian Basin (Tex. and N.M.) 2 Piceance Creek Basin 2 Piceance Creek Basin (Colo.) 2 Pitkin County 2 Prehistoric Trackways National Monument 2 Prehistoric Trackways National Monument (N.M.) 2 Rocky Mountains 2 San Juan Basin (N.M. and Colo.) 2 San Miguel County 2 Sandoval County 2 Santa Fe County 2 Scurry County 2 Seven Devils Mountains 2 Snake River Valley (Wyo.-Wash.) 2 Snowdrift Mountain 2 Torrance County 2 Uinta Basin (Utah and Colo.) 2 Valencia County 2 Washington Region 2 Weber County 2 Wrangell Mountains 2 Yeso Formation (N.M. and Tex.) 2 Afghanistan 1 Alaska, Southeast 1 Amador County 1 Belden Formation (Colo.) 1 Brown County (Tex.) 1 Calaveras County 1 California, Southern 1 Central Oklahoma Aquifer 1 Central Oklahoma Aquifer Region 1 Chaves County 1 Coleman County (Tex.) 1 Cowley County 1 Denver Basin 1 Eagle Mountains region 1 Eagle River Watershed 1 Eagle Valley Formation (Colo.) 1 Eddy County 1 Elk County 1 Glass Mountains (Tex.) 1 Gondwana (Continent) 1 Grand Canyon 1 Grand Canyon Region 1 Greer County 1 Guadalupe Mountains (N.M. and Tex.) 1 Hardin County 1 Idaho, South Central 1