Region
United States
20
Alaska
8
California
5
Sun
5
Nevada
4
Colorado
3
Florida
3
Hawaii
3
Massachusetts
3
Montana
3
Columbia River Watershed
2
Earth (Planet)
2
Kilauea Volcano (Hawaii)
2
Massachusetts Bay
2
Mexico, Gulf of
2
New Mexico
2
North America
2
North Pacific Region
2
Outer space
2
Stellwagen Bank National Marine Sanctuary (Mass.)
2
Wyoming
2
Yucca Mountain Region
2
Africa
1
Alaska Peninsula
1
Aleutian Islands
1
Appalachian Basin
1
Arizona
1
Bear Lake (Utah and Idaho)
1
Beaufort Sea
1
Belly River Region (Mont. and Alta.)
1
Big Thompson River Valley
1
Cascade Range
1
Central America
1
China
1
Cook Inlet Region
1
East Asia
1
Everglades Region
1
Fort Huachuca
1
Great Plains
1
Great Smoky Mountains National Park (N.C. and Tenn.)
1
Idaho
1
Illinois
1
Illinois Basin
1
Indiana
1
Kansas
1
Kentucky
1
Kilauea Volcano
1
Klamath River Watershed (Or. and Calif.)
1
Loma Prieta Region
1
Long Valley Caldera
1
more ...