Public Sites
| State | County | Name |
|---|---|---|
| Iowa | Delaware | Coffins Grove County Park |
| Iowa | Keokuk | Coffman Woods |
| Iowa | Linn | Coggon |
| South Dakota | Fall River | Cold Brook Lake |
| Iowa | Cass | Cold Springs Park |
| Iowa | Winneshiek | Cold Water Springs State Preserve |
| Iowa | Jasper | Colfax |
| Iowa | Jasper | Colfax Wildlife Area |
| Iowa | Black Hawk | College Square Mall |
| Iowa | Story | Collins |
| Iowa | Story | Colo Bogs |
| Iowa | Tama | Columbia Wildlife Area |
| Iowa | Lucas | Colyn Wildlife Management Area |
| Colorado | Las Animas | Comanche National Grassland |
| Iowa | Jasper | Conard Environmental Research Area |
| Iowa | Louisa | Cone Marsh State Wildlife Management Area |
| Iowa | Muscatine | Conesville |
| Iowa | Muscatine | Conesville Fen |
| Iowa | Johnson | Conklin Quarry |
| Iowa | Winneshiek | Coon Creek Wildlife Management Area |
| Iowa | Polk | Cooper Creek Lake Park |
| West Virginia | Monongalia | Cooper Rock State Forest |
| Iowa | Pocahontas | Cooper's Cove County Park |
| Iowa | Kossuth | Copp Prairie Waterfowl Production Area |
| Iowa | Washington | Coppock Access |