Spatial Coverage
- Clarence Strait Region1
- Clark County1
- Clermont-Ferrand1
- Clermont-Ferrand (France)1
- Cleveland1
- Congo (Brazzaville)1
- Connecticut River1
- Coosaw River (S.C.)1
- Core Sound (N.C.)1
- Costilla County1
- Cottonwood River Watershed1
- Cottonwood River Watershed (Minn.)1
- Cuyahoga River (Ohio)1
- Damariscotta River (Me.)1
- De Tour Passage (Mich.)1
- Denali National Park and Preserve Region1
- Dismal Swamp Canal (N.C. and Va.)1
- Duxbury1
- Duxbury Bay (Mass.)1
- East (U.S.)1