Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Swisher City Hall | Building | 237 | Johnson | 41 50 45 N | 091 41 55 W |
| Swisher Creek | Stream | | Johnson | 41 48 21 N | 091 39 48 W |
| Swisher Post Office | Post Office | 240 | Johnson | 41 50 50 N | 091 41 41 W |
| Swiss Cemetery | Cemetery | 348 | Humboldt | 42 50 57 N | 094 01 29 W |
| Swiss Valley | Valley | | Dubuque | 42 26 33 N | 090 43 47 W |
| Swiss Valley Nature Center | Locale | 233 | Dubuque | 42 25 20 N | 090 45 30 W |
| Swiss Valley Park | Park | 233 | Dubuque | 42 25 20 N | 090 45 30 W |
| Switzer Cemetery | Cemetery | 238 | Jefferson | 41 02 13 N | 091 54 36 W |
| Swope Hall | Building | 436 | Buena Vista | 42 38 31 N | 095 12 35 W |
| Sycamore Creek | Stream | | Scott | 41 34 55 N | 090 22 17 W |
| Sycamore Mall | Locale | | Johnson | 41 38 28 N | 091 30 42 W |
| Sycamore Mall | Locale | 220 | Washington | 41 14 11 N | 091 33 53 W |
| Sycamore Park | Park | 244 | Polk | 41 40 41 N | 093 40 15 W |
| Sycamore Village | Populated Place | 355 | Cass | 41 24 25 N | 094 59 51 W |
| Sylvan Lake (historical) | Lake | 440 | Dickinson | 43 21 32 N | 095 15 47 W |
| Sylvan Post Office (historical) | Post Office | 356 | Clayton | 42 40 50 N | 091 29 31 W |
| Sylvan Retreat | Locale | 343 | Humboldt | 42 40 27 N | 094 11 06 W |
| Sylvan Retreat Post Office (historical) | Post Office | 343 | Humboldt | 42 40 27 N | 094 11 06 W |
| Sylvia Enarson Elementary School | School | 330 | Montgomery | 40 56 01 N | 094 58 56 W |
| Synder Access Recreation Area | Park | 304 | Bremer | 42 49 36 N | 092 15 06 W |
| Synod Cemetery | Cemetery | 385 | Winnebago | 43 24 34 N | 093 31 26 W |
| Synod Cemetery | Cemetery | 396 | Winnebago | 43 29 16 N | 093 37 05 W |
| Synod Lutheran Church | Church | 381 | Winnebago | 43 24 52 N | 093 31 31 W |
| Syracuse State Wildlife Management Area | Park | 204 | Clinton | 41 50 25 N | 090 47 51 W |
| Syrian Cemetery | Cemetery | 234 | Linn | 41 58 27 N | 091 38 51 W |
| T F Clark State Park | Park | 269 | Tama | 42 13 35 N | 092 25 15 W |
| T'lam Cemetery | Cemetery | 241 | Marion | 41 23 06 N | 092 58 55 W |
| Tabernacle Baptist Church | Church | 262 | Davis | 40 45 07 N | 092 25 21 W |
| Tabernacle Baptist Church | Church | 241 | Johnson | 41 41 50 N | 091 35 06 W |
| Tabernacle Baptist Church | Church | 417 | Lyon | 43 20 30 N | 095 59 57 W |
| Tabernacle Baptist Church | Church | 301 | Pottawattamie | 41 15 47 N | 095 51 53 W |
| Tabernacle Church of God | Church | 358 | Woodbury | 42 30 11 N | 096 25 19 W |
| Table Mound Mobile Home Park | Populated Place | 235 | Dubuque | 42 27 20 N | 090 40 20 W |
| Table Mound School | School | 246 | Dubuque | 42 27 36 N | 090 40 48 W |
| Table Rock Site of July 4 1838 Celebration Historical Marker | Park | 219 | Clayton | 42 50 60 N | 091 23 45 W |
| Tabor | Populated Place | 382 | Fremont | 40 53 54 N | 095 40 17 W |
| Tabor (historical) | Locale | 382 | Fremont | 40 53 54 N | 095 40 17 W |
| Tabor Cemetery | Cemetery | 376 | Mills | 40 54 14 N | 095 40 46 W |
| Tabor Cemetery | Cemetery | 388 | Montgomery | 41 03 34 N | 095 03 33 W |
| Tabor Church | Church | 392 | Montgomery | 41 03 32 N | 095 03 24 W |
| Tabor City Park | Park | 383 | Fremont | 40 53 59 N | 095 40 30 W |
| Tabor College (historical) | School | 382 | Fremont | 40 53 54 N | 095 40 17 W |
| Tabor Manor Care Center | Hospital | 382 | Fremont | 40 53 54 N | 095 40 17 W |
| Tabor Post Office | Post Office | 382 | Fremont | 40 53 54 N | 095 40 17 W |
| Tabor Public Library | Building | 382 | Fremont | 40 53 54 N | 095 40 17 W |
| Taft Junior High School | School | 255 | Linn | 41 58 49 N | 091 44 18 W |
| Taft Park | Park | 332 | Humboldt | 42 43 30 N | 094 12 59 W |
| Taintor | Populated Place | 269 | Mahaska | 41 30 04 N | 092 44 19 W |
| Taintor (historical) | Locale | 269 | Mahaska | 41 30 04 N | 092 44 19 W |
| Taintor Community Church | Church | 269 | Mahaska | 41 30 04 N | 092 44 19 W |
| Taintor Post Office | Post Office | 269 | Mahaska | 41 30 04 N | 092 44 19 W |
| Tait Cummins Memorial Park | Park | 219 | Linn | 41 56 50 N | 091 38 23 W |
| Talbert Family Cemetery | Cemetery | 193 | Des Moines | 40 44 55 N | 091 07 21 W |
| Talisman Park | Park | 329 | Humboldt | 42 43 53 N | 094 12 51 W |
| Tallahoma Post Office (historical) | Post Office | 311 | Lucas | 41 05 20 N | 093 28 17 W |
| Talleyrand | Populated Place | 237 | Keokuk | 41 17 42 N | 091 57 55 W |
| Talleyrand Cemetery | Cemetery | 232 | Keokuk | 41 17 43 N | 091 58 17 W |
| Talleyrand Post Office (historical) | Post Office | 237 | Keokuk | 41 17 42 N | 091 57 55 W |
| Tallman Cemetery | Cemetery | 226 | Henry | 41 05 50 N | 091 29 51 W |
| Tallman Museum | Building | 416 | Cherokee | 42 45 26 N | 095 34 22 W |
| Tallview Terrace Mobile Home Park | Populated Place | 364 | Woodbury | 42 31 25 N | 096 21 26 W |
| Talmage | Populated Place | 328 | Union | 41 01 37 N | 094 06 43 W |
| Talmage Hill Park | Park | 349 | Union | 41 01 32 N | 094 05 36 W |
| Talmage Hill Wildlife Area | Park | 320 | Union | 41 01 47 N | 094 05 51 W |
| Talmage Junction | Locale | 328 | Union | 41 01 21 N | 094 07 01 W |
| Talmage Post Office (historical) | Post Office | 328 | Union | 41 01 37 N | 094 06 43 W |
| Tama | Locale | 247 | Tama | 41 57 40 N | 092 34 19 W |
| Tama | Populated Place | 256 | Tama | 41 58 00 N | 092 34 37 W |
| Tama Airport | Airport | 247 | Tama | 41 56 60 N | 092 34 36 W |
| Tama Beach Access | Locale | 158 | Des Moines | 40 52 45 N | 091 02 46 W |
| Tama Civic Center | Building | 250 | Tama | 41 57 46 N | 092 34 48 W |
| Tama County | Civil | 313 | Tama | 42 04 00 N | 092 32 01 W |
| Tama County Courthouse | Building | 274 | Tama | 41 59 46 N | 092 34 44 W |
| Tama County Fairgrounds | Locale | 297 | Tama | 42 11 23 N | 092 43 31 W |
| Tama County Historical Museum | Building | 274 | Tama | 41 59 49 N | 092 34 43 W |
| Tama County Home | Building | 308 | Tama | 42 02 02 N | 092 33 46 W |
| Tama County Lake Dam | Dam | 281 | Tama | 42 02 31 N | 092 31 10 W |
| Tama County Lake Park | Park | 282 | Tama | 42 02 49 N | 092 31 17 W |
| Tama County Sheriff Office | Building | 271 | Tama | 41 59 45 N | 092 34 47 W |
| Tama Fire Department | Building | 250 | Tama | 41 57 46 N | 092 34 48 W |
| Tama Hall | Building | 281 | Black Hawk | 42 25 53 N | 092 19 46 W |
| Tama Intermediate School | School | 259 | Tama | 41 58 05 N | 092 34 46 W |
| Tama Medical Center | Hospital | 250 | Tama | 41 57 46 N | 092 34 44 W |
| Tama Mud Creek | Stream | | Tama | 41 56 60 N | 092 33 44 W |
| Tama Police Headquarters | Building | 250 | Tama | 41 57 46 N | 092 34 48 W |
| Tama Post Office | Post Office | 250 | Tama | 41 57 48 N | 092 34 36 W |
| Tama Primary School | School | 260 | Tama | 41 58 01 N | 092 34 34 W |
| Tama Public Library | Building | 250 | Tama | 41 57 47 N | 092 34 48 W |
| Tama School | School | 158 | Des Moines | 40 52 36 N | 091 03 23 W |
| Tama Toledo Country Club | Locale | 262 | Tama | 41 58 02 N | 092 35 00 W |
| Tamaville Post Office (historical) | Post Office | 269 | Tama | 41 58 40 N | 092 28 26 W |
| Tando-Winslow Cemetery | Cemetery | 394 | Taylor | 40 49 60 N | 094 37 01 W |
| Tangeman Cemetery | Cemetery | 280 | Clayton | 42 51 30 N | 091 08 30 W |
| Tank Pond Creek | Stream | | Webster | 42 13 17 N | 094 21 15 W |
| Tankersly Park | Park | 272 | Marshall | 42 03 01 N | 092 56 09 W |
| Tara | Locale | 350 | Webster | 42 30 02 N | 094 17 51 W |
| Tara | Populated Place | 348 | Webster | 42 30 01 N | 094 17 45 W |
| Tara Hills Country Club | Locale | 278 | Benton | 42 00 30 N | 092 07 21 W |
| Tara Post Office (historical) | Post Office | 356 | Webster | 42 28 58 N | 094 19 59 W |
| Tarecoat Creek | Stream | | Jackson | 42 10 51 N | 090 40 05 W |
| Tarkio City (historical) | Populated Place | 337 | Page | 40 43 57 N | 095 11 44 W |
| Tarkio Post Office (historical) | Post Office | 342 | Page | 40 44 35 N | 095 12 51 W |
| Tarr Residence Hall | Building | 268 | Linn | 41 55 27 N | 091 25 30 W |
| Tater Hill School | School | 302 | Appanoose | 40 53 29 N | 093 03 37 W |
| Tauher Park | Park | 259 | Linn | 42 02 40 N | 091 34 46 W |
| Taylor | Populated Place | 339 | Pottawattamie | 41 16 17 N | 095 31 12 W |
| Taylor Cemetery | Cemetery | 284 | Appanoose | 40 48 08 N | 092 38 31 W |
| Taylor Cemetery | Cemetery | 244 | Washington | 41 26 17 N | 091 49 51 W |
| Taylor County | Civil | 370 | Taylor | 40 45 02 N | 094 40 01 W |
| Taylor County Courthouse | Building | 348 | Taylor | 40 40 06 N | 094 43 12 W |