Region
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Colombia
1
Colorado
4
Colorado Plateau
2
Colorado River (Colo.-Mexico)
3
Columbia River Watershed
13
Cook County
1
Crater Lake National Park
1
Crater Lake National Park (Or.)
1
Craters of the Moon National Monument
1
Craters of the Moon National Monument (Idaho)
1
Craters of the Moon National Preserve
1
Craters of the Moon National Preserve (Idaho)
1
Crook County
1
Dauphin Island
3
Dauphin Island (Ala.)
1
Delaware River Watershed (N.Y.-Del. and N.J.)
2
Delta Region
3
Delta River
1
Denali National Park and Preserve (Alaska)
1
Des Plaines River Watershed (Wis. and Ill.)
1
Deschutes County
1
Deschutes River Valley
1
Deschutes River Watershed
1
Developing countries
1
EE.UU
1
Earth (Planet)
1
East Asia
1
Erie, Lake
2
Eureka County
2
Europe
1
Everglades
17
Everglades (Fla.)
12
Everglades National Park
5
Everglades National Park (Fla.)
5
Flagstaff Region
1
Flint River Watershed
1
Florida
40
Florida Bay
2
Fort Cronkhite (Calif.)
1
Fort Pulaski National Monument
1
Fort Pulaski National Monument (Ga.)
1
Gariep Basin
1
Gates of the Arctic National Park and Preserve (Alaska)
1
George Washington Carver National Monument
1
George Washington Carver National Monument (Mo.)
1
Georgia
2
Glen Canyon (Utah and Ariz.)
2
Glen Canyon Dam (Ariz.)
3
Golden Gate National Recreation Area (Calif.)
1
Great Barrier Reef (Qld.)
1
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