Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Hopkinton Family Medical Center | Hospital | 263 | Delaware | 42 20 38 N | 091 14 56 W |
| Hopkinton Feed and Grain Incorporated Elevator | Locale | 263 | Delaware | 42 20 28 N | 091 14 39 W |
| Hopkinton Post Office | Post Office | 263 | Delaware | 42 20 38 N | 091 14 55 W |
| Hopkinton Public Library | Building | 262 | Delaware | 42 20 36 N | 091 14 52 W |
| Hopkirk Cemetery | Cemetery | 205 | Jefferson | 41 00 11 N | 091 45 25 W |
| Hopper Gymnasium | Building | 294 | Warren | 41 21 57 N | 093 33 57 W |
| Hoprig | Populated Place | 383 | Emmet | 43 16 12 N | 094 37 10 W |
| Hoprig Post Office (historical) | Post Office | 383 | Emmet | 43 16 12 N | 094 37 10 W |
| Horace (historical) | Locale | 384 | Audubon | 41 39 46 N | 094 49 15 W |
| Horace Greeley - Editor Historical Marker | Park | 310 | Poweshiek | 41 44 32 N | 092 43 24 W |
| Horace Mann School | School | 177 | Clinton | 41 52 06 N | 090 10 56 W |
| Horace Post Office (historical) | Post Office | 384 | Audubon | 41 39 46 N | 094 49 15 W |
| Horan School | School | 217 | Wapello | 40 54 49 N | 092 23 28 W |
| Horizon Elementary School | School | 296 | Polk | 41 39 60 N | 093 45 21 W |
| Horizon Park | Park | 293 | Polk | 41 44 30 N | 093 37 11 W |
| Horn (historical) | Locale | 265 | Jasper | 41 47 58 N | 093 02 21 W |
| Horn Cemetery | Cemetery | 288 | Davis | 40 39 25 N | 092 37 32 W |
| Horn Elementary School | School | 229 | Johnson | 41 39 03 N | 091 33 47 W |
| Horn Memorial Hospital | Hospital | 382 | Ida | 42 20 20 N | 095 27 35 W |
| Horn Post Office (historical) | Post Office | 278 | Jasper | 41 48 50 N | 093 02 21 W |
| Hornick | Populated Place | 324 | Woodbury | 42 13 50 N | 096 05 51 W |
| Hornick (historical) | Locale | 325 | Woodbury | 42 13 40 N | 096 05 48 W |
| Hornick City Hall | Building | 324 | Woodbury | 42 13 50 N | 096 05 51 W |
| Hornick Fire Department | Building | 324 | Woodbury | 42 13 50 N | 096 05 51 W |
| Hornick Post Office | Post Office | 324 | Woodbury | 42 13 50 N | 096 05 51 W |
| Horridge House | Building | 244 | Benton | 42 09 55 N | 092 01 27 W |
| Horse Creek | Stream | | Fremont | 40 40 13 N | 095 49 40 W |
| Horse Creek Ditch | Canal | 281 | Fremont | 40 42 59 N | 095 47 39 W |
| Horse Grove - Rietz Forest Area | Park | 351 | Wright | 42 44 00 N | 093 34 11 W |
| Horse Island | Island | 170 | Scott | 41 28 00 N | 090 39 14 W |
| Horse Shoe Lake | Lake | 179 | Jefferson | 41 03 29 N | 091 43 40 W |
| Horseshoe Bend County Recreation Area | Park | 429 | Dickinson | 43 18 30 N | 095 12 01 W |
| Horseshoe Bend Trail | Trail | 430 | Dickinson | 43 18 31 N | 095 12 02 W |
| Horseshoe Bend Wildlife Area - West Unit | Park | 315 | Greene | 42 06 55 N | 094 36 01 W |
| Horseshoe Bluff | Cliff | 235 | Dubuque | 42 27 46 N | 090 38 06 W |
| Horseshoe Lake | Lake | 305 | Clinton | 41 37 55 N | 096 03 12 W |
| Horseshoe Lake | Lake | 439 | Dickinson | 43 26 26 N | 095 08 59 W |
| Horseshoe Lake | Lake | 305 | Harrison | 41 37 57 N | 096 03 08 W |
| Horseshoe Lake | Lake | 178 | Louisa | 41 22 58 N | 091 24 50 W |
| Horseshoe Lake | Lake | 244 | Polk | 41 39 06 N | 093 39 29 W |
| Horseshoe Lake | Lake | 188 | Washington | 41 14 03 N | 091 50 01 W |
| Horseshoe Lake | Lake | 332 | Woodbury | 42 21 14 N | 095 53 37 W |
| Horseshoe Pond County Park | Park | 206 | Jackson | 42 03 20 N | 090 39 40 W |
| Horst Farm Cemetery | Cemetery | 245 | Jackson | 42 06 00 N | 090 17 00 W |
| Horstman School | School | 244 | Marion | 41 13 53 N | 093 18 25 W |
| Horticulture Hall | Building | 288 | Story | 42 01 40 N | 093 38 41 W |
| Horton | Populated Place | 291 | Bremer | 42 50 51 N | 092 28 32 W |
| Horton Baptist Church | Church | 299 | Bremer | 42 50 52 N | 092 28 22 W |
| Horton Cemetery | Cemetery | 291 | Bremer | 42 50 31 N | 092 28 36 W |
| Horton Cemetery | Cemetery | 330 | Clarke | 40 58 18 N | 093 38 01 W |
| Horton Creek | Stream | | Bremer | 42 49 29 N | 092 30 24 W |
| Horton Creek | Stream | | Lee | 40 31 49 N | 091 24 35 W |
| Horton Post Office (historical) | Post Office | 291 | Bremer | 42 50 51 N | 092 28 32 W |
| Horton Township Cemetery | Cemetery | 483 | Osceola | 43 26 36 N | 095 32 38 W |
| Horton Township Cemetery Prairie Preserve | Park | 484 | Osceola | 43 26 30 N | 095 32 43 W |
| Hoskins (historical) | Locale | 360 | Woodbury | 42 28 32 N | 096 16 51 W |
| Hoskins Cemetery | Cemetery | 232 | Van Buren | 40 41 13 N | 092 02 05 W |
| Hoskins Creek | Stream | | Ida | 42 20 07 N | 095 23 50 W |
| Hoskins Post Office (historical) | Post Office | 360 | Woodbury | 42 28 32 N | 096 16 51 W |
| Hospers | Locale | 409 | Sioux | 43 04 22 N | 095 54 25 W |
| Hospers | Populated Place | 411 | Sioux | 43 04 19 N | 095 54 16 W |
| Hospers Cemetery | Cemetery | 416 | Sioux | 43 04 24 N | 095 55 12 W |
| Hospers Christian School | School | 415 | Sioux | 43 04 15 N | 095 54 01 W |
| Hospers Elementary School | School | 414 | Sioux | 43 04 12 N | 095 54 15 W |
| Hospers Fire Department | Building | 411 | Sioux | 43 04 19 N | 095 54 16 W |
| Hospers Hall | Building | 437 | Sioux | 42 59 57 N | 096 03 22 W |
| Hospers Medical Clinic | Hospital | 411 | Sioux | 43 04 18 N | 095 54 17 W |
| Hospers Memorial Cemetery | Cemetery | 415 | Sioux | 43 04 10 N | 095 53 06 W |
| Hospers Post Office | Post Office | 410 | Sioux | 43 04 20 N | 095 54 21 W |
| Hottes Lake Wildlife Management Area | Park | 427 | Dickinson | 43 28 46 N | 095 08 12 W |
| Houg Cemetery | Cemetery | 253 | Clayton | 42 56 40 N | 091 34 04 W |
| Hough Cemetery | Cemetery | 287 | Monroe | 40 57 00 N | 092 42 31 W |
| Houghton | Populated Place | 218 | Lee | 40 47 01 N | 091 36 11 W |
| Houghton (historical) | Locale | 219 | Lee | 40 47 04 N | 091 36 32 W |
| Houghton Cemetery | Cemetery | 278 | Benton | 42 06 32 N | 092 16 47 W |
| Houghton City Hall | Building | 218 | Lee | 40 47 01 N | 091 36 11 W |
| Houghton Library | Building | 218 | Lee | 40 47 01 N | 091 36 11 W |
| Houghton Post Office | Post Office | 218 | Lee | 40 47 01 N | 091 36 11 W |
| House of Dolls Museum | Building | 373 | Palo Alto | 43 06 44 N | 094 40 55 W |
| House of Praise Family Church | Church | 276 | Warren | 41 22 28 N | 093 33 29 W |
| House of Prayer Church | Church | 175 | Scott | 41 27 35 N | 090 48 25 W |
| House of the Lord Mission | Church | 216 | Scott | 41 32 05 N | 090 34 53 W |
| Houser Cemetery | Cemetery | 346 | Page | 40 36 37 N | 095 15 35 W |
| Houtz Cemetery | Cemetery | 216 | Muscatine | 41 24 54 N | 091 12 01 W |
| Hovey Cemetery | Cemetery | 349 | Webster | 42 37 47 N | 094 10 24 W |
| Hovey Cemetery | Cemetery | 348 | Webster | 42 37 47 N | 094 10 25 W |
| Hovie Island | Island | 187 | Clayton | 42 53 16 N | 091 06 37 W |
| Howar Junior High School | School | 301 | Appanoose | 40 43 32 N | 092 52 35 W |
| Howard Cemetery | Cemetery | 210 | Cedar | 41 44 55 N | 091 17 31 W |
| Howard Cemetery | Cemetery | 359 | Howard | 43 15 06 N | 092 26 15 W |
| Howard Cemetery | Cemetery | 261 | Mahaska | 41 20 30 N | 092 51 41 W |
| Howard Center Post Office (historical) | Post Office | 372 | Howard | 43 22 17 N | 092 13 12 W |
| Howard Center Township Cemetery | Cemetery | 380 | Howard | 43 22 43 N | 092 13 28 W |
| Howard County | Civil | 387 | Howard | 43 21 00 N | 092 19 01 W |
| Howard County Courthouse | Building | 395 | Howard | 43 22 25 N | 092 06 57 W |
| Howard County Equity Co-op Elevator | Locale | 352 | Chickasaw | 43 11 55 N | 092 24 60 W |
| Howard County Fairground | Locale | 394 | Howard | 43 22 36 N | 092 07 46 W |
| Howard County Farm | Building | 384 | Howard | 43 23 57 N | 092 08 46 W |
| Howard County Law Library | Building | 395 | Howard | 43 22 25 N | 092 06 57 W |
| Howard County Log Cabin Museum | Building | 396 | Howard | 43 22 17 N | 092 07 05 W |
| Howard County Museum | Building | 399 | Howard | 43 22 37 N | 092 07 17 W |
| Howard County Sherriffs Office | Building | 395 | Howard | 43 22 25 N | 092 06 56 W |
| Howard Creek | Stream | | Clayton | 42 55 46 N | 091 23 00 W |
| Howard District School (historical) | School | 392 | Allamakee | 43 19 06 N | 091 27 07 W |
| Howard Dormitory | Building | 232 | Jefferson | 41 01 00 N | 091 58 08 W |
| Howard Grove Cemetery | Cemetery | 226 | Jefferson | 41 08 56 N | 091 56 32 W |
| Howard Hall | Building | 293 | Polk | 41 36 04 N | 093 39 06 W |
| Howard Lake | Lake | 230 | Polk | 41 30 23 N | 093 20 32 W |
| Howard Park | Park | 235 | Jefferson | 41 00 37 N | 091 57 48 W |
| Howard Post Office (historical) | Post Office | 309 | Tama | 42 07 00 N | 092 33 41 W |