Spatial Coverage
- China1
- Clark County (Ark.)1
- Clay County (N.C.)1
- Clayton County (Iowa)1
- Coal County1
- Coeur d'Alene Mining District (Idaho)1
- Coeur d'Alene Mining District.1
- Connecticut1
- Crater Lake National Park (Or.)1
- Crater Lake National Park.1
- Crawford County (Wis.)1
- Croatia1
- Curry County1
- Dallas County (Ark.)1
- Davidson County (Tenn.)1
- Dekalb County (Ala.)1
- Delaware County (Iowa)1
- Dorchester County (Md.)1
- Easton (Wash.)1
- Edwards County (Ill.)1
