Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Coffman Cemetery | Cemetery | 201 | Washington | 41 29 20 N | 091 45 31 W |
| Coffman Wood Preserve | Park | 241 | Keokuk | 41 28 10 N | 092 04 59 W |
| Cog Railway Elevator Historical Marker | Park | 197 | Dubuque | 42 29 50 N | 090 40 05 W |
| Coggon | Locale | 278 | Linn | 42 16 51 N | 091 32 01 W |
| Coggon | Populated Place | 284 | Linn | 42 16 51 N | 091 31 50 W |
| Coggon Cemetery | Cemetery | 302 | Linn | 42 16 18 N | 091 31 47 W |
| Coggon City Fire Department | Building | 286 | Linn | 42 16 44 N | 091 31 49 W |
| Coggon City Town Hall | Building | 284 | Linn | 42 16 51 N | 091 31 51 W |
| Coggon Elementary Center | School | 282 | Linn | 42 16 53 N | 091 31 40 W |
| Coggon Police Department | Building | 284 | Linn | 42 16 51 N | 091 31 51 W |
| Coggon Post Office | Post Office | 284 | Linn | 42 16 51 N | 091 31 51 W |
| Coggon Public Library | Building | 283 | Linn | 42 16 50 N | 091 31 46 W |
| Cogley Physicians Clinic | Hospital | 317 | Mills | 41 02 52 N | 095 44 24 W |
| Cogley Physicians Clinic | Hospital | 308 | Mills | 41 00 10 N | 095 35 04 W |
| Cogley Physicians Clinic | Hospital | 338 | Pottawattamie | 41 26 59 N | 095 36 58 W |
| Cogley Physicians Clinic | Hospital | 326 | Pottawattamie | 41 16 06 N | 095 50 03 W |
| Cohen Cemetery | Cemetery | 250 | Mahaska | 41 10 01 N | 092 48 17 W |
| Coin | Populated Place | 302 | Page | 40 39 16 N | 095 13 49 W |
| Coin (historical) | Locale | 304 | Page | 40 39 20 N | 095 13 51 W |
| Coin City Hall | Building | 302 | Page | 40 39 16 N | 095 13 49 W |
| Coin Library | Building | 302 | Page | 40 39 16 N | 095 13 49 W |
| Coin Post Office | Post Office | 302 | Page | 40 39 16 N | 095 13 49 W |
| Colbyville Post Office (historical) | Post Office | 317 | Story | 41 53 30 N | 093 37 11 W |
| Colcord Point | Cape | 427 | Dickinson | 43 24 21 N | 095 09 31 W |
| Cold Springs | Lake | 341 | Cass | 41 17 30 N | 095 05 08 W |
| Cold Springs State Park | Park | 347 | Cass | 41 17 24 N | 095 05 10 W |
| Cold Stream | Stream | | Linn | 41 59 49 N | 091 40 36 W |
| Cold Water Creek | Stream | | Winneshiek | 43 25 44 N | 091 56 32 W |
| Cold Water Post Office (historical) | Post Office | 323 | Delaware | 42 33 55 N | 091 27 41 W |
| Cold Water Springs State Wildlife Area | Area | 339 | Winneshiek | 43 26 28 N | 091 57 38 W |
| Coldville Post Office (historical) | Post Office | 326 | Tama | 42 16 15 N | 092 42 29 W |
| Coldwater Cemetery | Cemetery | 298 | Butler | 42 50 38 N | 092 47 18 W |
| Coldwater Creek | Stream | | Butler | 42 50 40 N | 092 45 36 W |
| Coldwater Post Office (historical) | Post Office | 341 | Cerro Gordo | 42 56 10 N | 093 02 43 W |
| Coldwater Post Office (historical) | Post Office | 332 | Franklin | 42 53 30 N | 093 03 01 W |
| Cole Creek | Stream | | O'Brien | 42 54 41 N | 095 43 41 W |
| Cole Hall | Building | 293 | Polk | 41 36 04 N | 093 39 06 W |
| Cole Landing Strip | Airport | 370 | Mills | 40 57 05 N | 095 23 56 W |
| Cole Park | Park | 197 | Jackson | 42 15 35 N | 090 25 52 W |
| Coleman Memorial County Park | Park | 224 | Lee | 40 47 59 N | 091 42 12 W |
| Coleman School | School | 339 | Webster | 42 28 53 N | 094 10 29 W |
| Colenbrander Hall | Building | 438 | Sioux | 42 59 55 N | 096 03 22 W |
| Colesburg | Populated Place | 352 | Delaware | 42 38 22 N | 091 12 07 W |
| Colesburg City hall | Building | 352 | Delaware | 42 38 22 N | 091 12 07 W |
| Colesburg Library | Building | 352 | Delaware | 42 38 22 N | 091 12 07 W |
| Colesburg Post Office | Post Office | 352 | Delaware | 42 38 22 N | 091 12 07 W |
| Colesburg Roadside Park | Park | 324 | Delaware | 42 37 00 N | 091 11 40 W |
| Colesburg United Methodist Church | Church | 352 | Delaware | 42 38 22 N | 091 12 07 W |
| Colfax | Locale | 242 | Jasper | 41 40 42 N | 093 14 50 W |
| Colfax | Populated Place | 244 | Jasper | 41 40 40 N | 093 14 43 W |
| Colfax Cemetery | Cemetery | 345 | Webster | 42 31 21 N | 094 01 11 W |
| Colfax Center Cemetery | Cemetery | 329 | Grundy | 42 25 39 N | 092 49 40 W |
| Colfax Center Church | Church | 329 | Grundy | 42 25 42 N | 092 49 40 W |
| Colfax City Hall | Building | 244 | Jasper | 41 40 39 N | 093 14 44 W |
| Colfax Family Care Associates Center | Hospital | 244 | Jasper | 41 40 40 N | 093 14 40 W |
| Colfax Golf Club | Locale | 277 | Jasper | 41 39 55 N | 093 15 11 W |
| Colfax Number Three School (historical) | School | 292 | Grundy | 42 20 30 N | 092 40 31 W |
| Colfax Post Office | Post Office | 249 | Jasper | 41 40 43 N | 093 14 35 W |
| Colfax Presbyterian Church | Church | 245 | Jasper | 41 40 39 N | 093 14 41 W |
| Colfax Public Hunting Area | Area | 238 | Jasper | 41 41 42 N | 093 13 01 W |
| Colfax Public Library | Building | 245 | Jasper | 41 40 37 N | 093 14 47 W |
| Colfax Townhall | Building | 341 | Webster | 42 30 56 N | 094 01 47 W |
| Colfax Township Hall | Locale | 382 | Pocahontas | 42 36 09 N | 094 44 14 W |
| Colfax Township Hall | Locale | 340 | Webster | 42 30 56 N | 094 01 48 W |
| Colfax United Methodist Church | Church | 244 | Jasper | 41 40 36 N | 093 14 50 W |
| Colfax-Mingo Elementary School | School | 249 | Jasper | 41 40 33 N | 093 14 44 W |
| Colfax-Mingo High School | School | 281 | Jasper | 41 40 43 N | 093 13 53 W |
| Colfax-Mingo Middle School | School | 273 | Jasper | 41 45 51 N | 093 17 16 W |
| Colgrove-Walker Hall | Building | 315 | Fayette | 42 50 25 N | 091 47 56 W |
| College Avenue Christian Church | Church | 295 | Polk | 41 36 28 N | 093 40 41 W |
| College Avenue Friends Church | Church | 254 | Mahaska | 41 18 12 N | 092 38 54 W |
| College Cemetery | Cemetery | 293 | Story | 42 01 50 N | 093 39 15 W |
| College Courts | Building | 274 | Black Hawk | 42 30 36 N | 092 27 49 W |
| College Creek | Stream | | Story | 42 01 30 N | 093 37 53 W |
| College Green Park | Park | 201 | Johnson | 41 39 36 N | 091 31 39 W |
| College Hall | Building | 282 | Linn | 41 55 26 N | 091 25 22 W |
| College Hall | Building | 293 | Warren | 41 21 50 N | 093 33 51 W |
| College Hill Lutheran Church | Church | 280 | Black Hawk | 42 30 58 N | 092 27 14 W |
| College Medical Associates Center | Hospital | 227 | Jefferson | 41 01 20 N | 091 58 11 W |
| College of Design | Building | 293 | Story | 42 01 43 N | 093 39 11 W |
| College of Medicine Administration Building | Building | 217 | Johnson | 41 39 40 N | 091 32 44 W |
| College of Veterinary Medicine | Building | 284 | Story | 42 00 26 N | 093 37 57 W |
| College Park | Park | 336 | Montgomery | 41 00 40 N | 095 13 25 W |
| College Relations Office | Building | 267 | Marion | 41 23 60 N | 092 55 09 W |
| College Springs | Populated Place | 351 | Page | 40 37 09 N | 095 07 15 W |
| College Springs City Hall | Building | 351 | Page | 40 37 09 N | 095 07 15 W |
| College Springs Post Office | Post Office | 351 | Page | 40 37 09 N | 095 07 15 W |
| College Square Mall | Locale | 284 | Black Hawk | 42 30 38 N | 092 25 44 W |
| Collegetowne Plaza | Locale | 285 | Bremer | 42 43 33 N | 092 28 59 W |
| Collegiate Church | Church | 294 | Polk | 41 35 49 N | 093 39 52 W |
| Collegiate Honor House | Building | 267 | Marion | 41 24 12 N | 092 55 09 W |
| Collegiate Presbyterian Church | Church | 296 | Story | 42 01 31 N | 093 39 18 W |
| Collegiate United Methodist Church | Church | 290 | Story | 42 01 18 N | 093 39 13 W |
| Coller Airstrip | Airport | 270 | Black Hawk | 42 23 60 N | 092 04 01 W |
| Collett | Populated Place | 228 | Jefferson | 40 54 22 N | 091 58 40 W |
| Collett (historical) | Locale | 228 | Jefferson | 40 54 22 N | 091 58 40 W |
| Collett Post Office (historical) | Post Office | 228 | Jefferson | 40 54 22 N | 091 58 40 W |
| Collin House | Building | 281 | Linn | 41 55 34 N | 091 25 41 W |
| Collins | Populated Place | 304 | Story | 41 54 10 N | 093 18 23 W |
| Collins (historical) | Locale | 307 | Story | 41 53 60 N | 093 18 21 W |
| Collins Cemetery | Cemetery | 240 | Davis | 40 38 40 N | 092 20 31 W |
| Collins Cemetery | Cemetery | 311 | Story | 41 53 54 N | 093 17 26 W |
| Collins Christian Church | Church | 306 | Story | 41 54 08 N | 093 18 19 W |
| Collins City Hall | Building | 307 | Story | 41 54 06 N | 093 18 18 W |
| Collins Grove | Locale | 297 | Tama | 42 08 58 N | 092 31 60 W |
| Collins Grove Post Office | Post Office | 286 | Tama | 42 08 45 N | 092 32 01 W |
| Collins Maxwell Middle School | School | 272 | Story | 41 53 28 N | 093 23 51 W |
| Collins Post Office | Post Office | 305 | Story | 41 54 04 N | 093 18 27 W |
| Collins Public Library | Building | 307 | Story | 41 54 06 N | 093 18 18 W |
| Collins-Maxwell Elementary School | School | 308 | Story | 41 54 13 N | 093 18 11 W |