Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| The Beach Ottumwa | Building | 195 | Wapello | 41 00 44 N | 092 24 56 W |
| The Central Market | Building | 266 | Marion | 41 24 07 N | 092 55 08 W |
| The Chapel | Building | 267 | Marion | 41 24 08 N | 092 55 13 W |
| The Church of God of Prophecy | Church | 222 | Scott | 41 34 26 N | 090 35 23 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 240 | Benton | 41 53 60 N | 092 17 21 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 272 | Black Hawk | 42 28 47 N | 092 21 13 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 279 | Black Hawk | 42 30 48 N | 092 24 32 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 349 | Boone | 42 04 41 N | 093 52 14 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 277 | Buchanan | 42 27 60 N | 091 53 51 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 395 | Carroll | 42 04 35 N | 094 52 51 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 372 | Cass | 41 24 15 N | 094 59 03 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 341 | Cerro Gordo | 43 08 20 N | 093 10 51 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 377 | Cerro Gordo | 43 08 16 N | 093 22 40 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 348 | Clarke | 41 01 55 N | 093 46 14 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 403 | Clay | 43 08 55 N | 095 10 03 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 215 | Clinton | 41 51 30 N | 090 14 00 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 211 | Des Moines | 40 50 10 N | 091 07 40 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 312 | Fayette | 42 50 41 N | 091 48 29 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 323 | Greene | 42 00 15 N | 094 22 42 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 332 | Harrison | 41 38 35 N | 095 47 20 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 290 | Jasper | 41 42 35 N | 093 02 09 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 207 | Jefferson | 40 58 48 N | 091 59 49 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 217 | Johnson | 41 38 48 N | 091 29 48 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 172 | Lee | 40 23 45 N | 091 23 02 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 238 | Linn | 41 59 10 N | 091 36 18 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 255 | Linn | 42 01 60 N | 091 37 21 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 254 | Linn | 41 55 58 N | 091 25 55 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 276 | Marion | 41 19 55 N | 093 06 56 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 279 | Marshall | 42 02 24 N | 092 55 57 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 292 | Marshall | 42 06 45 N | 092 59 19 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 216 | Muscatine | 41 25 29 N | 091 04 31 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 210 | Muscatine | 41 34 13 N | 091 15 40 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 332 | Page | 40 45 18 N | 095 21 37 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 247 | Polk | 41 30 41 N | 093 21 27 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 293 | Polk | 41 43 54 N | 093 35 21 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 278 | Polk | 41 37 47 N | 093 44 10 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 278 | Polk | 41 33 06 N | 093 34 59 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 262 | Polk | 41 36 13 N | 093 36 31 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 288 | Polk | 41 35 08 N | 093 45 00 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 300 | Pottawattamie | 41 16 13 N | 095 52 38 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 198 | Scott | 41 31 37 N | 090 34 27 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 225 | Scott | 41 34 17 N | 090 38 53 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 293 | Story | 42 02 50 N | 093 37 46 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 174 | Van Buren | 40 43 49 N | 091 57 45 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 255 | Wapello | 41 03 37 N | 092 24 51 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 293 | Warren | 41 21 47 N | 093 33 56 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 232 | Washington | 41 17 55 N | 091 41 36 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 340 | Webster | 42 31 10 N | 094 08 55 W |
| The Church of Jesus Christ of Latter Day Saints | Church | 348 | Woodbury | 42 31 38 N | 096 25 21 W |
| The Church of Jesus Christ of Latter-Day Saints | Church | 230 | Dubuque | 42 29 00 N | 090 41 35 W |
| The Commons | Building | 271 | Linn | 41 55 33 N | 091 25 33 W |
| The Dragoon Trail in Marion County Historical Marker | Park | 254 | Marion | 41 22 32 N | 093 06 36 W |
| The Dragoons - Mitchell County Historical Marker | Park | 352 | Mitchell | 43 17 56 N | 092 48 41 W |
| The Dragroon Trail Historical Marker | Park | 254 | Wapello | 41 03 35 N | 092 25 01 W |
| The Hogback | Summit | 251 | Linn | 42 05 33 N | 091 48 41 W |
| The Inn Golf Course | Locale | 445 | Dickinson | 43 23 20 N | 095 08 46 W |
| The Inn Post Office (historical) | Post Office | 431 | Dickinson | 43 23 15 N | 095 09 03 W |
| The Legacy Golf Course | Locale | 280 | Warren | 41 29 35 N | 093 40 31 W |
| The Mainstay | Building | 289 | Polk | 41 36 16 N | 093 39 08 W |
| The Maples | Park | 421 | Sac | 42 16 05 N | 095 14 41 W |
| The Meadows | Populated Place | 259 | Polk | 41 30 52 N | 093 39 16 W |
| The Mormon Trail Historical Marker | Park | 298 | Lucas | 41 00 02 N | 093 18 31 W |
| The Mormon Trail State Historical Marker | Park | 333 | Clarke | 41 00 50 N | 093 47 51 W |
| The Mormon Trail State Historical Marker | Park | 294 | Decatur | 40 39 20 N | 093 51 16 W |
| The Narrows | Channel | 297 | Pottawattamie | 41 17 45 N | 095 53 48 W |
| The Narrows Point | Cape | 426 | Dickinson | 43 24 41 N | 095 04 47 W |
| The Pahoja Recreation Trail | Trail | 428 | Lyon | 43 22 50 N | 096 27 51 W |
| The Phelps House | Building | 195 | Des Moines | 40 48 44 N | 091 06 21 W |
| The Playhouse | Building | 436 | Sioux | 42 59 57 N | 096 03 33 W |
| The Residence | Building | 282 | Bremer | 42 43 45 N | 092 28 51 W |
| The Secret Garden | Locale | 214 | Des Moines | 40 49 50 N | 091 18 51 W |
| The Shaw Center | Building | 340 | Decatur | 40 36 57 N | 093 55 28 W |
| The Valley Church | Church | 223 | Scott | 41 35 22 N | 090 27 50 W |
| The Willow Patch Post Office (historical) | Post Office | 161 | Des Moines | 40 49 16 N | 091 06 01 W |
| The Yellow Banks Cemetery | Cemetery | 183 | Lee | 40 24 31 N | 091 29 12 W |
| Theatre Arts Wing/New World Theatre | Building | 446 | Sioux | 43 04 56 N | 096 10 06 W |
| Theatre Building | Building | 198 | Johnson | 41 40 00 N | 091 32 22 W |
| Theatre Museum of Repertoire Americana | Building | 220 | Henry | 40 57 18 N | 091 32 51 W |
| Thelman Wildlife Area | Park | 328 | Fayette | 42 58 20 N | 092 02 01 W |
| Theophile Brughier Log Cabin | Building | 332 | Woodbury | 42 29 45 N | 096 28 36 W |
| Thie Farm Cemetery | Cemetery | 200 | Des Moines | 40 55 10 N | 091 11 21 W |
| Third Creek | Stream | | Boone | 42 00 05 N | 093 54 38 W |
| Third Missionary Baptist Church | Church | 217 | Scott | 41 32 03 N | 090 34 33 W |
| Third Presbyterian Church | Church | 231 | Dubuque | 42 31 45 N | 090 40 10 W |
| Third Presbyterian Church | Church | 364 | Woodbury | 42 29 11 N | 096 22 13 W |
| Third Reformed Church | Church | 261 | Marion | 41 24 08 N | 092 53 53 W |
| Third Street Cemetery | Cemetery | 195 | Dubuque | 42 29 47 N | 090 40 02 W |
| Third Ward Park | Park | 228 | Jackson | 42 03 45 N | 090 39 47 W |
| Thirty | Populated Place | 311 | Appanoose | 40 41 46 N | 092 52 04 W |
| Thirty Acre Park | Park | 269 | Jasper | 41 41 10 N | 093 01 16 W |
| Thomas | Locale | 330 | Ringgold | 40 36 37 N | 094 13 27 W |
| Thomas Cemetery | Cemetery | 311 | Appanoose | 40 42 39 N | 092 54 06 W |
| Thomas Cemetery | Cemetery | 322 | Wayne | 40 38 00 N | 093 18 37 W |
| Thomas Ditch | Stream | | Fremont | 40 43 21 N | 095 01 15 W |
| Thomas Edison Educational Center | School | 176 | Scott | 41 31 35 N | 090 30 36 W |
| Thomas Jefferson Elementary School | School | 282 | Jasper | 41 42 03 N | 093 04 35 W |
| Thomas Lake | Lake | 227 | Marion | 41 28 28 N | 093 18 08 W |
| Thomas Mitchell County Park | Park | 275 | Polk | 41 38 38 N | 093 22 41 W |
| Thomas Park | Park | 234 | Linn | 42 01 46 N | 091 36 39 W |
| Thomas Pit Access | Locale | 442 | Osceola | 43 21 15 N | 095 31 26 W |
| Thomas Post Office (historical) | Post Office | 330 | Ringgold | 40 36 37 N | 094 13 27 W |
| Thomas Rest Haven | Hospital | 358 | Carroll | 41 52 17 N | 094 40 28 W |
| Thomas Rhodes Historical Marker | Park | 175 | Van Buren | 40 42 05 N | 091 48 31 W |
| Thomas Roberts High School | School | 262 | Winneshiek | 43 18 24 N | 091 47 06 W |
| Thomasville | Populated Place | 308 | Clayton | 42 45 14 N | 091 34 52 W |
| Thompson | Locale | 455 | Audubon | 41 48 13 N | 094 55 01 W |
| Thompson | Populated Place | 387 | Winnebago | 43 22 17 N | 093 46 25 W |
| Thompson (historical) | Locale | 386 | Winnebago | 43 22 25 N | 093 46 16 W |
| Thompson Cemetery | Cemetery | 371 | Adams | 41 03 09 N | 094 54 54 W |
| Thompson Cemetery | Cemetery | 336 | Greene | 42 02 30 N | 094 30 06 W |