Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Clinton Plaza West Shopping Center | Locale | 196 | Clinton | 41 48 55 N | 090 14 00 W |
| Clinton Police Department | Building | 180 | Clinton | 41 50 23 N | 090 11 13 W |
| Clinton Post Office | Post Office | 181 | Clinton | 41 50 34 N | 090 11 09 W |
| Clinton Public Library | Building | 181 | Clinton | 41 50 17 N | 090 11 27 W |
| Clinton School | School | 286 | Lucas | 40 59 58 N | 093 27 38 W |
| Clinton Stock Yards | Populated Place | 187 | Clinton | 41 49 00 N | 090 13 21 W |
| Clinton-Garfield Cemetery | Cemetery | 359 | Pocahontas | 42 48 20 N | 094 31 13 W |
| Clio | Locale | 336 | Wayne | 40 38 15 N | 093 27 19 W |
| Clio | Populated Place | 339 | Wayne | 40 38 06 N | 093 27 05 W |
| Clio Cemetery | Cemetery | 333 | Wayne | 40 38 03 N | 093 27 56 W |
| Clio Post Office | Post Office | 340 | Wayne | 40 38 05 N | 093 26 56 W |
| Clipper | Locale | 304 | Ringgold | 40 34 54 N | 094 20 21 W |
| Clipper Post Office (historical) | Post Office | 331 | Ringgold | 40 34 43 N | 094 20 04 W |
| Clive | Locale | 273 | Polk | 41 36 30 N | 093 44 23 W |
| Clive | Populated Place | 254 | Polk | 41 36 11 N | 093 43 27 W |
| Clive City Hall | Building | 268 | Polk | 41 36 28 N | 093 46 31 W |
| Clive Fire Department | Building | 265 | Polk | 41 36 29 N | 093 44 09 W |
| Clive Police Department | Building | 265 | Polk | 41 36 29 N | 093 44 09 W |
| Clive Post Office (historical) | Post Office | 254 | Polk | 41 36 11 N | 093 43 27 W |
| Clive Public Library | Building | 268 | Polk | 41 36 28 N | 093 46 31 W |
| Clive School | School | 260 | Polk | 41 36 30 N | 093 43 05 W |
| Cloie Branch | Stream | | Dubuque | 42 33 15 N | 090 44 46 W |
| Clore Cemetery | Cemetery | 312 | Lucas | 41 06 57 N | 093 27 41 W |
| Close Cemetery | Cemetery | 302 | Madison | 41 18 53 N | 093 51 09 W |
| Clothier Cemetery | Cemetery | 247 | Iowa | 41 32 08 N | 092 02 27 W |
| Cloud | Populated Place | 286 | Marion | 41 10 30 N | 093 14 07 W |
| Cloud (historical) | Locale | 286 | Marion | 41 10 30 N | 093 14 07 W |
| Cloud Post Office (historical) | Post Office | 286 | Marion | 41 10 30 N | 093 14 07 W |
| Clover Hill School | School | 270 | Warren | 41 30 18 N | 093 36 57 W |
| Clover Hills Shopping Center | Locale | 214 | Clinton | 41 51 32 N | 090 12 35 W |
| Clover Ridge United Methodist Church | Church | 246 | Benton | 41 52 44 N | 091 50 05 W |
| Cloverdale | Populated Place | 466 | Osceola | 43 20 49 N | 095 41 09 W |
| Cloverdale (historical) | Locale | 466 | Osceola | 43 20 45 N | 095 41 06 W |
| Cloverdale Park | Park | 264 | Black Hawk | 42 31 50 N | 092 21 46 W |
| Cloverdale Post Office (historical) | Post Office | 466 | Osceola | 43 20 49 N | 095 41 09 W |
| Clucas | Populated Place | 300 | Madison | 41 29 48 N | 094 03 07 W |
| Clutier | Populated Place | 270 | Tama | 42 04 46 N | 092 24 08 W |
| Clutier (historical) | Locale | 262 | Tama | 42 04 40 N | 092 24 16 W |
| Clutier Cemetery | Cemetery | 277 | Tama | 42 04 45 N | 092 23 10 W |
| Clutier City Hall | Building | 266 | Tama | 42 04 45 N | 092 24 15 W |
| Clutier Community Church | Church | 268 | Tama | 42 04 44 N | 092 24 08 W |
| Clutier Fire Department | Building | 266 | Tama | 42 04 45 N | 092 24 15 W |
| Clutier Post Office | Post Office | 266 | Tama | 42 04 45 N | 092 24 15 W |
| Clutier Public Library | Building | 266 | Tama | 42 04 45 N | 092 24 15 W |
| Clutterville Post Office (historical) | Post Office | 305 | Butler | 42 42 03 N | 092 59 46 W |
| Clutterville School (historical) | School | 333 | Hardin | 42 33 15 N | 093 02 57 W |
| Clyde | Populated Place | 298 | Jasper | 41 50 31 N | 093 15 55 W |
| Clyde P Mease Elementary School | School | 344 | Humboldt | 42 43 19 N | 094 12 10 W |
| Clyde Post Office (historical) | Post Office | 298 | Jasper | 41 50 31 N | 093 15 55 W |
| Clyde Williams Field | Park | 294 | Story | 42 01 25 N | 093 39 11 W |
| CMC at West Ninth Heliport | Airport | 279 | Black Hawk | 42 27 47 N | 092 20 42 W |
| Co-op Elevator Association - Sibley Elevator | Locale | 460 | Osceola | 43 23 49 N | 095 45 06 W |
| Co-op Grain and Product Company Elevator | Locale | 391 | Emmet | 43 17 41 N | 094 30 42 W |
| Co-operative Grain and Product Company Elevator | Locale | 381 | Emmet | 43 23 46 N | 094 28 42 W |
| Coal Bank Hill Bridge | Bridge | 289 | Hardin | 42 22 52 N | 093 05 48 W |
| Coal City | Populated Place | 250 | Appanoose | 40 35 50 N | 092 43 08 W |
| Coal City Post Office (historical) | Post Office | 256 | Appanoose | 40 35 40 N | 092 43 08 W |
| Coal Creek | Populated Place | 260 | Keokuk | 41 26 16 N | 092 23 37 W |
| Coal Creek | Stream | | Dallas | 41 33 02 N | 094 06 03 W |
| Coal Creek | Stream | | Keokuk | 41 20 13 N | 092 18 30 W |
| Coal Creek | Stream | | Mahaska | 41 14 41 N | 092 45 42 W |
| Coal Creek | Stream | | Monroe | 41 02 03 N | 092 51 46 W |
| Coal Creek | Stream | | Polk | 41 27 57 N | 093 20 57 W |
| Coal Creek Bridge | Bridge | 232 | Warren | 41 25 45 N | 093 20 46 W |
| Coal Creek Cemetery | Cemetery | 223 | Mahaska | 41 14 23 N | 092 46 41 W |
| Coal Creek Post Office | Post Office | 260 | Keokuk | 41 26 16 N | 092 23 37 W |
| Coal Glen | School | 248 | Lucas | 41 07 05 N | 093 06 60 W |
| Coal Glen Church | Church | 296 | Lucas | 41 07 20 N | 093 07 38 W |
| Coal Glen School | School | 288 | Lucas | 41 05 19 N | 093 06 48 W |
| Coal Port | Locale | 220 | Jefferson | 40 59 46 N | 091 45 57 W |
| Coal Ridge Cemetery | Cemetery | 251 | Marion | 41 22 42 N | 093 01 26 W |
| Coal Ridge Church Cemetery | Cemetery | 253 | Marion | 41 22 41 N | 093 01 24 W |
| Coal Ridge School | School | 255 | Marion | 41 10 32 N | 092 59 18 W |
| Coal Siding (historical) | Populated Place | 248 | Jasper | 41 40 15 N | 093 03 22 W |
| Coal Valley | Populated Place | 273 | Boone | 42 01 54 N | 093 57 03 W |
| Coal Valley Creek | Stream | | Boone | 42 01 40 N | 093 56 41 W |
| Coalfield (historical) | Locale | 223 | Monroe | 41 07 06 N | 092 41 51 W |
| Coalfield Post Office (historical) | Post Office | 223 | Monroe | 41 07 06 N | 092 41 51 W |
| Coalton Post Office (historical) | Post Office | 269 | Monroe | 41 06 33 N | 092 59 35 W |
| Coalville | Populated Place | 340 | Webster | 42 26 43 N | 094 07 33 W |
| Coalville (historical) | Locale | 340 | Webster | 42 26 43 N | 094 07 33 W |
| Coalville Post Office (historical) | Post Office | 340 | Webster | 42 26 43 N | 094 07 33 W |
| Cobb Creek | Stream | | Harrison | 41 50 12 N | 095 55 49 W |
| Cobb Farm Airport | Airport | 333 | Wayne | 40 43 41 N | 093 20 36 W |
| Cobb Memorial Park | Park | 371 | Ida | 42 21 03 N | 095 28 31 W |
| Cobbville Creek | Stream | | Decatur | 40 48 18 N | 093 40 06 W |
| Coburg | Locale | 306 | Montgomery | 40 54 60 N | 095 16 01 W |
| Coburg | Populated Place | 307 | Montgomery | 40 55 03 N | 095 15 52 W |
| Coburg Post Office (historical) | Post Office | 307 | Montgomery | 40 55 03 N | 095 15 52 W |
| Cochran Cemetery | Cemetery | 287 | Warren | 41 12 26 N | 093 22 01 W |
| Cochran Park | Park | 299 | Pottawattamie | 41 15 37 N | 095 52 34 W |
| Cocklin Fish Farm | Park | 337 | Cass | 41 15 15 N | 095 08 06 W |
| Codfish Cemetery | Cemetery | 228 | Jackson | 42 04 22 N | 090 34 46 W |
| Codner Cemetery | Cemetery | 279 | Butler | 42 34 30 N | 092 43 31 W |
| Cody Chute | Stream | | Des Moines | 41 01 08 N | 090 57 25 W |
| Cody School | School | 223 | Scott | 41 36 42 N | 090 22 10 W |
| Coe Apartments | Building | 228 | Linn | 41 59 15 N | 091 39 23 W |
| Coe College | School | 230 | Linn | 41 59 11 N | 091 39 26 W |
| Coe College Nursing Education Building | Building | 230 | Linn | 41 59 11 N | 091 39 35 W |
| Coe Creek | Stream | | Montgomery | 41 08 46 N | 095 10 33 W |
| Coe House | Building | 227 | Linn | 41 59 19 N | 091 39 28 W |
| Coe's Grove Post Office (historical) | Post Office | 335 | Montgomery | 41 07 01 N | 095 10 29 W |
| Coelo Post Office (historical) | Post Office | 356 | Union | 40 55 53 N | 094 24 56 W |
| Coffee Creek | Stream | | Dubuque | 42 32 42 N | 091 06 58 W |
| Coffin's Grove Post Office (historical) | Post Office | 295 | Delaware | 42 29 40 N | 091 32 01 W |
| Coffin's Grove Stagecoach House (historical) | Building | 298 | Delaware | 42 29 37 N | 091 32 01 W |
| Coffins Creek | Stream | | Delaware | 42 29 56 N | 091 28 21 W |
| Coffins Grove Cemetery | Cemetery | 293 | Delaware | 42 29 57 N | 091 31 47 W |
| Coffins Grove County Park | Park | 293 | Delaware | 42 29 40 N | 091 31 51 W |
| Coffman Cemetery | Cemetery | 266 | Marion | 41 21 30 N | 093 00 31 W |