California 24
Washington (State) 9
North America 8
Alaska 6
Colorado 6
Idaho 6
Nevada 6
New York (State) 6
Wyoming 6
Great Basin 5
Michigan 5
North Carolina 5
West (U.S.) 5
Wisconsin 5
Amchitka Island 4
Utah 4
Kansas 3
Long Island 3
Maryland 3
Montana 3
New England 3
New Mexico 3
Snake River Plain (Idaho and Or.) 3
South Dakota 3
Virginia 3
Arizona 2
Bonneville, Lake 2
Chesapeake Bay Region (Md. and Va.) 2
Clinton County 2
Connecticut 2
Deep Springs Valley 2
Delmarva Peninsula 2
Enewetak Atoll 2
Essex County 2
Franklin County 2
Fulton County 2
Georgia 2
Glacier National Park Region 2
Glenns Ferry Formation (Idaho) 2
Graham County 2
Great Lakes (North America) 2
Great Plains 2
Gros Ventre River Valley 2
Illinois 2
Inyo County 2
Iowa 2
Isle Royale National Park 2
Kentucky 2
Louisiana 2
Manix Lake 2
Manix Lake (Calif.) 2
Marshall Islands 2
Missoula, Lake 2
New Jersey 2
North Dakota 2
Northeastern States 2
Quinebaug, Lake 2
Rocky Mountains 2
Russia (Federation) 2
Saint Helens, Mount 2
Sanpoil River Valley 2
Scotland 2
South America 2
Tularosa Valley (N.M. and Tex.) 2
Upper Peninsula 2
White Sands National Monument 2
White Sands National Park (N.M.) 2
Altai Mountains 1
America 1
Andes Region 1
Arctic regions 1
Argentina 1
Australia 1
Beaufort Sea 1
Belize 1
Boulder County 1
California, Southern 1
Central Valley (Valley) 1
Chile 1
Chowan River Watershed 1
Colorado River Valley (Colo.-Mexico) 1
Delaware 1
Denver 1
Denver Basin 1
Denver Region 1
England 1
Eurasia 1
Florida 1
Fremont County 1
Front Range (Colo. and Wyo.) 1
Great Lakes Region (North America) 1
Great Salt Lake 1
Hawaii 1
Hungary 1
Indian Ocean 1
Indiana 1
Isle Royale National Park (Mich.) 1
Jackson Hole 1
Japan 1
Jefferson County 1