Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| First Church of Christ Scientist | Church | 272 | Black Hawk | 42 31 58 N | 092 27 13 W |
| First Church of Christ Scientist | Church | 377 | Cerro Gordo | 43 08 17 N | 093 22 44 W |
| First Church of Christ Scientist | Church | 178 | Clinton | 41 50 30 N | 090 11 54 W |
| First Church of Christ Scientist | Church | 229 | Linn | 41 59 06 N | 091 39 20 W |
| First Church of Christ Scientist | Church | 302 | Pottawattamie | 41 15 24 N | 095 51 11 W |
| First Church of Christ Scientist | Church | 285 | Story | 42 01 58 N | 093 36 49 W |
| First Church of God | Church | 279 | Polk | 41 37 47 N | 093 40 34 W |
| First Church of God | Church | 199 | Wapello | 41 00 58 N | 092 26 21 W |
| First Church of God | Church | 227 | Washington | 41 10 15 N | 091 49 23 W |
| First Church of the Nazarene | Church | 265 | Black Hawk | 42 33 45 N | 092 28 21 W |
| First Church of the Nazarene | Church | 345 | Cerro Gordo | 43 08 49 N | 093 11 26 W |
| First Church of the Nazarene | Church | 210 | Clinton | 41 53 40 N | 090 12 29 W |
| First Church of the Nazarene | Church | 219 | Clinton | 41 52 28 N | 090 12 34 W |
| First Church of the Nazarene | Church | 234 | Jefferson | 41 00 32 N | 091 58 08 W |
| First Church of the Nazarene | Church | 251 | Jones | 42 14 18 N | 091 11 14 W |
| First Church of the Nazarene | Church | 253 | Linn | 41 58 04 N | 091 42 46 W |
| First Church of the Nazarene | Church | 251 | Mahaska | 41 17 35 N | 092 37 53 W |
| First Church of the Nazarene | Church | 281 | Marshall | 42 02 06 N | 092 54 47 W |
| First Church of the Nazarene | Church | 303 | Mills | 41 02 34 N | 095 44 45 W |
| First Church of the Nazarene | Church | 287 | Polk | 41 37 47 N | 093 40 56 W |
| First Church of the Nazarene | Church | 299 | Pottawattamie | 41 15 47 N | 095 53 05 W |
| First Church of the Nazarene | Church | 202 | Scott | 41 31 50 N | 090 37 28 W |
| First Church of the Nazarene | Church | 196 | Wapello | 41 00 02 N | 092 24 57 W |
| First Church of the Nazarene | Church | 338 | Webster | 42 31 08 N | 094 09 56 W |
| First Church of the Nazarene | Church | 371 | Woodbury | 42 28 42 N | 096 20 41 W |
| First Church of the Open Bible | Church | 258 | Black Hawk | 42 29 29 N | 092 20 13 W |
| First Church of the Open Bible | Church | 236 | Linn | 41 58 40 N | 091 41 59 W |
| First Church of the Open Bible | Church | 255 | Mahaska | 41 17 29 N | 092 38 46 W |
| First Church of the Open Bible | Church | 254 | Mahaska | 41 17 15 N | 092 44 11 W |
| First Church of the Open Bible | Church | 297 | Polk | 41 36 52 N | 093 40 23 W |
| First Church of the Open Bible | Church | 212 | Wapello | 41 00 32 N | 092 26 49 W |
| First Church United | Church | 215 | Muscatine | 41 34 46 N | 091 15 48 W |
| First Church/Cemetery Historical Marker | Park | 330 | Hardin | 42 18 56 N | 093 11 18 W |
| First Co-op Association Elevator | Locale | 377 | Clay | 42 55 04 N | 095 20 43 W |
| First Co-op Association Elevator | Locale | 428 | Sac | 42 30 03 N | 095 17 39 W |
| First Co-op Elevator | Locale | 384 | Buena Vista | 42 53 36 N | 095 09 04 W |
| First College in Kossuth County Historical Marker | Park | 358 | Kossuth | 43 05 45 N | 094 13 41 W |
| First College West of the Mississippi Historical Marker | Park | 222 | Henry | 40 58 21 N | 091 33 09 W |
| First Congregational Church | Church | 260 | Benton | 41 53 54 N | 092 16 37 W |
| First Congregational Church | Church | 264 | Black Hawk | 42 29 31 N | 092 20 43 W |
| First Congregational Church | Church | 385 | Buena Vista | 42 36 14 N | 094 59 59 W |
| First Congregational Church | Church | 298 | Butler | 42 34 24 N | 092 47 22 W |
| First Congregational Church | Church | 402 | Clay | 43 09 02 N | 095 08 46 W |
| First Congregational Church | Church | 213 | Clayton | 43 01 06 N | 091 10 58 W |
| First Congregational Church | Church | 317 | Clayton | 42 51 48 N | 091 14 04 W |
| First Congregational Church | Church | 232 | Clayton | 42 51 17 N | 091 24 04 W |
| First Congregational Church | Church | 189 | Clinton | 41 51 11 N | 090 11 36 W |
| First Congregational Church | Church | 171 | Des Moines | 40 48 38 N | 091 06 16 W |
| First Congregational Church | Church | 195 | Dubuque | 42 30 09 N | 090 40 08 W |
| First Congregational Church | Church | 307 | Floyd | 43 04 13 N | 092 40 38 W |
| First Congregational Church | Church | 351 | Franklin | 42 44 26 N | 093 12 30 W |
| First Congregational Church | Church | 342 | Hardin | 42 31 20 N | 093 15 60 W |
| First Congregational Church | Church | 330 | Hardin | 42 21 41 N | 093 05 53 W |
| First Congregational Church | Church | 395 | Howard | 43 22 31 N | 092 06 55 W |
| First Congregational Church | Church | 251 | Jones | 42 14 18 N | 091 11 14 W |
| First Congregational Church | Church | 261 | Jones | 42 06 22 N | 091 17 05 W |
| First Congregational Church | Church | 368 | Kossuth | 43 03 60 N | 094 14 07 W |
| First Congregational Church | Church | 238 | Linn | 41 58 15 N | 091 41 41 W |
| First Congregational Church | Church | 395 | Lyon | 43 16 46 N | 096 13 58 W |
| First Congregational Church | Church | 285 | Marshall | 42 02 56 N | 092 55 08 W |
| First Congregational Church | Church | 317 | Mills | 41 02 54 N | 095 44 33 W |
| First Congregational Church | Church | 328 | Montgomery | 41 00 34 N | 095 13 28 W |
| First Congregational Church | Church | 297 | Polk | 41 40 10 N | 093 21 23 W |
| First Congregational Church | Church | 332 | Pottawattamie | 41 18 33 N | 095 23 54 W |
| First Congregational Church | Church | 304 | Pottawattamie | 41 15 36 N | 095 51 11 W |
| First Congregational Church | Church | 362 | Woodbury | 42 32 57 N | 096 24 16 W |
| First Congregational United Church | Church | 211 | Clayton | 43 01 06 N | 091 10 57 W |
| First Congregational United Church | Church | 218 | Clinton | 41 49 35 N | 090 32 19 W |
| First Congregational United Church | Church | 319 | Hamilton | 42 27 59 N | 093 49 09 W |
| First Congregational United Church of Christ | Church | 344 | Cerro Gordo | 43 09 11 N | 093 11 57 W |
| First Conservative Baptist Church | Church | 300 | Buchanan | 42 28 35 N | 092 03 43 W |
| First Cooperative Association Elevator | Locale | 417 | Buena Vista | 42 43 45 N | 095 10 58 W |
| First Cooperative Association Elevator | Locale | 412 | Cherokee | 42 46 50 N | 095 33 46 W |
| First Cooperative Association Elevator | Locale | 445 | Cherokee | 42 48 44 N | 095 42 46 W |
| First Court In Iowa Historical Marker | Park | 241 | Keokuk | 41 20 00 N | 092 12 16 W |
| First Courthouse in Iowa Historical Marker | Park | 223 | Henry | 40 57 58 N | 091 33 14 W |
| First Covenant Church | Church | 333 | Cerro Gordo | 43 08 52 N | 093 10 33 W |
| First Covenant Church | Church | 316 | Montgomery | 41 00 39 N | 095 13 46 W |
| First Covenant Church | Church | 342 | Webster | 42 29 36 N | 094 12 22 W |
| First Covenant Church | Church | 400 | Woodbury | 42 31 58 N | 096 23 33 W |
| First Creek | Stream | | Boone | 42 00 42 N | 093 55 23 W |
| First Eden Cemetery | Cemetery | 271 | Benton | 42 06 33 N | 091 59 04 W |
| First English Lutheran Church | Church | 402 | Clay | 43 08 53 N | 095 08 39 W |
| First Evangelical Church | Church | 413 | Cass | 41 19 51 N | 094 51 02 W |
| First Evangelical Church | Church | 331 | Clayton | 42 58 19 N | 091 10 33 W |
| First Evangelical Free Church | Church | 282 | Black Hawk | 42 27 60 N | 092 21 01 W |
| First Evangelical Free Church | Church | 268 | Black Hawk | 42 31 45 N | 092 26 45 W |
| First Evangelical Free Church | Church | 291 | Story | 42 02 39 N | 093 38 13 W |
| First Evangelical Free Church | Church | 345 | Webster | 42 30 59 N | 094 09 07 W |
| First Evangelical Free Church | Church | 347 | Woodbury | 42 29 59 N | 096 24 19 W |
| First Evangelical Lutheran Cemetery | Cemetery | 329 | Clayton | 42 58 17 N | 091 10 32 W |
| First Evangelical Lutheran Church | Church | 307 | Appanoose | 40 43 35 N | 092 52 16 W |
| First Farmers Co-op Company Elevator | Locale | 365 | Cherokee | 42 44 44 N | 095 33 33 W |
| First Farmers Co-op Elevator | Locale | 415 | Cherokee | 42 51 39 N | 095 32 43 W |
| First Farmers Cooperative Elevator | Locale | 430 | Cherokee | 42 47 41 N | 095 38 04 W |
| First Federated Church | Church | 265 | Linn | 41 55 20 N | 091 23 13 W |
| First Federated Church | Church | 294 | Polk | 41 36 42 N | 093 41 01 W |
| First Flour Mill in Iowa Historical Marker | Park | 165 | Henry | 40 49 45 N | 091 26 11 W |
| First Foursquare Church | Church | 215 | Wapello | 41 00 30 N | 092 23 21 W |
| First Free Methodist Church | Church | 278 | Polk | 41 37 48 N | 093 43 43 W |
| First Friends Church | Church | 304 | Marshall | 42 01 10 N | 092 55 21 W |
| First Friends Church | Church | 282 | Polk | 41 37 47 N | 093 40 02 W |
| First Friends Church | Church | 303 | Poweshiek | 41 42 60 N | 092 43 44 W |
| First Grace Brethern Church | Church | 252 | Polk | 41 36 43 N | 093 36 03 W |
| First Hebrew Church of the First Born | Church | 258 | Black Hawk | 42 29 16 N | 092 19 41 W |
| First Home in Mount Pleasant Historical Marker | Park | 208 | Henry | 40 57 40 N | 091 33 41 W |
| First House in Grinnell Historical Marker | Park | 310 | Poweshiek | 41 44 32 N | 092 43 24 W |
| First Iowa State Fair 1854 Historical Marker | Park | 236 | Jefferson | 41 00 36 N | 091 58 05 W |
| First Legislative Assembly of Iowa Territory Historical Marker | Park | 172 | Des Moines | 40 48 40 N | 091 06 09 W |
| First Log Cabin in Kossuth County Historical Marker | Park | 338 | Kossuth | 43 03 25 N | 094 14 41 W |