Feature Name | Class | Elev. meters | County | Latitude DMS | Longitude DMS |
| Magor Township Cemetery | Cemetery | 352 | Hancock | 42 57 37 N | 093 54 39 W |
| Mahanay Bell Tower | Tower | 320 | Greene | 42 01 24 N | 094 22 36 W |
| Maharishi International University | School | 227 | Jefferson | 41 01 00 N | 091 57 53 W |
| Maharishi Patanjali Golden Dome | Building | 230 | Jefferson | 41 01 17 N | 091 57 56 W |
| Maharishi University of Management Library | Building | 231 | Jefferson | 41 01 04 N | 091 58 10 W |
| Maharishi Veda Bhavan Building | Building | 230 | Jefferson | 41 01 01 N | 091 58 02 W |
| Maharishi Vedic City | Populated Place | 241 | Jefferson | 41 03 09 N | 091 59 42 W |
| Maharry Lake | Reservoir | 383 | Taylor | 40 53 44 N | 094 33 16 W |
| Mahaska County | Civil | 247 | Mahaska | 41 20 00 N | 092 39 01 W |
| Mahaska County Courthouse | Building | 257 | Mahaska | 41 17 42 N | 092 38 37 W |
| Mahaska County Farm | Building | 225 | Mahaska | 41 17 02 N | 092 45 56 W |
| Mahaska County Farm Cemetery | Cemetery | 220 | Mahaska | 41 16 55 N | 092 46 05 W |
| Mahaska County Hospital | Hospital | 252 | Mahaska | 41 17 57 N | 092 37 47 W |
| Mahaska County Hospital Heliport | Airport | 274 | Mahaska | 41 18 02 N | 093 37 48 W |
| Mahaska County Sheriffs Office | Building | 257 | Mahaska | 41 17 42 N | 092 38 37 W |
| Mahaska Hall | Building | 250 | Wapello | 41 02 42 N | 092 23 41 W |
| Mahaska Physicians Clinic | Hospital | 248 | Mahaska | 41 18 00 N | 092 37 46 W |
| Mahoneys Bend | Bend | 219 | Jones | 42 10 25 N | 090 56 06 W |
| Main Building | Building | 289 | Winneshiek | 43 18 40 N | 091 48 23 W |
| Main Ditch | Canal | 365 | Palo Alto | 43 06 55 N | 094 37 01 W |
| Main Ditch Number 6 | Canal | 279 | Fremont | 40 41 32 N | 095 44 08 W |
| Main Residence Hall | Building | 312 | Poweshiek | 41 44 49 N | 092 43 03 W |
| Main Street Mall | Locale | 378 | Palo Alto | 43 06 52 N | 094 41 27 W |
| Main Street School | School | 268 | Black Hawk | 42 31 37 N | 092 26 42 W |
| Maine | Populated Place | 301 | Appanoose | 40 51 22 N | 092 51 42 W |
| Maine (historical) | Locale | 299 | Appanoose | 40 51 20 N | 092 51 51 W |
| Maintenance and Custodial Offices | Building | 260 | Dubuque | 42 29 40 N | 090 41 51 W |
| Maintenance and Power Building | Building | 232 | Dubuque | 42 30 14 N | 090 40 40 W |
| Maintenance Building | Building | 280 | Bremer | 42 43 37 N | 092 28 51 W |
| Maintenance Building | Building | 255 | Linn | 41 55 23 N | 091 25 37 W |
| Maintenance Building | Building | 293 | Polk | 41 44 10 N | 093 37 36 W |
| Maintenance Building | Building | 265 | Polk | 41 37 16 N | 093 36 16 W |
| Maintenance Building | Building | 319 | Pottawattamie | 41 16 13 N | 095 47 57 W |
| Maintenance Building | Building | 445 | Sioux | 43 05 00 N | 096 10 11 W |
| Maintenance Building | Building | 270 | Winneshiek | 43 18 31 N | 091 48 25 W |
| Maintenance Building | Building | 381 | Woodbury | 42 28 23 N | 096 21 33 W |
| Maintenance Storage and Horticulture Building | Building | 247 | Wapello | 41 02 45 N | 092 23 41 W |
| Makee Post Office (historical) | Post Office | 387 | Allamakee | 43 17 60 N | 091 28 41 W |
| Makee Township Cemetery | Cemetery | 386 | Allamakee | 43 17 54 N | 091 28 42 W |
| Malanaphy Springs | Spring | 281 | Winneshiek | 43 21 19 N | 091 50 06 W |
| Malanaphy Springs State Preserve | Park | 313 | Winneshiek | 43 20 40 N | 091 50 16 W |
| Malchow Mounds Preserve | Park | 167 | Des Moines | 40 59 30 N | 091 01 51 W |
| Malcolm Number Six School (historical) | School | 308 | Poweshiek | 41 43 35 N | 092 43 11 W |
| Malcom | Locale | 273 | Poweshiek | 41 42 18 N | 092 33 19 W |
| Malcom | Populated Place | 280 | Poweshiek | 41 42 30 N | 092 33 33 W |
| Malcom City Hall | Building | 287 | Poweshiek | 41 42 25 N | 092 33 21 W |
| Malcom Fire Department | Building | 287 | Poweshiek | 41 42 25 N | 092 33 21 W |
| Malcom Post Office | Post Office | 283 | Poweshiek | 41 42 23 N | 092 33 21 W |
| Malcom Presbyterian Church | Church | 286 | Poweshiek | 41 42 30 N | 092 33 11 W |
| Malcom United Methodist Church | Church | 286 | Poweshiek | 41 42 30 N | 092 33 11 W |
| Mall of the Bluffs | Locale | 306 | Pottawattamie | 41 14 45 N | 095 49 19 W |
| Mallard | Locale | 372 | Palo Alto | 42 56 15 N | 094 40 53 W |
| Mallard | Populated Place | 373 | Palo Alto | 42 56 11 N | 094 40 56 W |
| Mallard City Hall | Building | 378 | Palo Alto | 42 56 17 N | 094 41 16 W |
| Mallard Golf Course | Locale | 368 | Palo Alto | 42 56 05 N | 094 40 36 W |
| Mallard Marsh Dam Number One | Dam | 366 | Cerro Gordo | 43 14 36 N | 093 27 35 W |
| Mallard Marsh Dam Number Three | Dam | 368 | Cerro Gordo | 43 14 30 N | 093 28 04 W |
| Mallard Marsh Swamp | Swamp | 366 | Cerro Gordo | 43 14 31 N | 093 27 57 W |
| Mallard Post Office | Post Office | 377 | Palo Alto | 42 56 15 N | 094 41 07 W |
| Mallard Public Library | Building | 378 | Palo Alto | 42 56 17 N | 094 41 16 W |
| Mallard Schools | School | 372 | Palo Alto | 42 56 04 N | 094 40 55 W |
| Mallory (historical) | Locale | 390 | Shelby | 41 51 30 N | 095 18 56 W |
| Mallory Cemetery | Cemetery | 195 | Louisa | 41 08 59 N | 091 05 34 W |
| Mallory Memorial County Park | Park | 341 | Franklin | 42 39 46 N | 093 13 56 W |
| Mallory Post Office (historical) | Post Office | 390 | Shelby | 41 51 30 N | 095 18 56 W |
| Mallys Weh-Weh Neh-Kee Park | Park | 254 | Polk | 41 39 51 N | 093 32 50 W |
| Malmare Park | Park | 296 | Pottawattamie | 41 12 42 N | 095 54 21 W |
| Malone | Locale | 201 | Clinton | 41 48 47 N | 090 26 30 W |
| Malone | Locale | 200 | Crawford | 41 48 45 N | 090 26 29 W |
| Malone | Populated Place | 206 | Clinton | 41 49 15 N | 090 27 05 W |
| Malone Creek | Stream | | Buchanan | 42 27 29 N | 091 52 50 W |
| Malone Park | Park | 207 | Clinton | 41 48 37 N | 090 27 16 W |
| Malone Post Office (historical) | Post Office | 201 | Clinton | 41 48 48 N | 090 26 30 W |
| Malony Branch | Stream | | Crawford | 41 58 15 N | 095 10 16 W |
| Maloy | Populated Place | 337 | Ringgold | 40 40 28 N | 094 24 44 W |
| Maloy (historical) | Locale | 338 | Ringgold | 40 40 25 N | 094 24 36 W |
| Maloy Catholic Church | Church | 337 | Ringgold | 40 40 28 N | 094 24 44 W |
| Maloy Post Office | Post Office | 337 | Ringgold | 40 40 28 N | 094 24 44 W |
| Malta | Populated Place | 322 | Marshall | 41 58 15 N | 093 06 46 W |
| Malta (historical) | Locale | 321 | Marshall | 41 58 15 N | 093 07 01 W |
| Malta Post Office (historical) | Post Office | 321 | Marshall | 41 58 15 N | 093 07 01 W |
| Malton Post Office (historical) | Post Office | 369 | Plymouth | 42 42 17 N | 096 35 21 W |
| Malvern | Locale | 320 | Mills | 41 00 36 N | 095 35 05 W |
| Malvern | Populated Place | 307 | Mills | 41 00 10 N | 095 35 07 W |
| Malvern Cemetery | Cemetery | 340 | Mills | 40 59 19 N | 095 34 44 W |
| Malvern Family Medical Center | Hospital | 308 | Mills | 41 00 10 N | 095 35 04 W |
| Malvern Fire Station | Building | 307 | Mills | 41 00 06 N | 095 35 06 W |
| Malvern Junior-Senior High School | School | 333 | Mills | 41 00 50 N | 095 33 58 W |
| Malvern Post Office | Post Office | 304 | Mills | 41 00 09 N | 095 35 12 W |
| Malvern Public Library | Building | 311 | Mills | 41 00 13 N | 095 35 06 W |
| Mamie Creek | Stream | | Pottawattamie | 41 19 58 N | 095 39 44 W |
| Mamie Doud Eisenhower Birthplace | Building | 344 | Boone | 42 03 47 N | 093 53 07 W |
| Mamirelund Cemetery | Cemetery | 327 | Hamilton | 42 14 34 N | 093 32 28 W |
| Mammen | Populated Place | 425 | Plymouth | 42 51 05 N | 096 17 32 W |
| Mammen Post Office (historical) | Post Office | 423 | Plymouth | 42 51 03 N | 096 17 32 W |
| Mamre Cemetery | Cemetery | 379 | Montgomery | 40 59 11 N | 095 05 28 W |
| Mamrelund Cemetery | Cemetery | 363 | Montgomery | 40 58 52 N | 095 05 45 W |
| Mamrelund Lutheran Church | Church | 368 | Montgomery | 40 58 56 N | 095 05 60 W |
| Manatheka (historical) | Populated Place | 283 | Benton | 42 13 40 N | 091 52 14 W |
| Manawa Bend | Bend | 290 | Pottawattamie | 41 11 13 N | 095 51 14 W |
| Manawa City Park | Park | 296 | Pottawattamie | 41 12 40 N | 095 50 45 W |
| Manawa Power Centre | Locale | 299 | Pottawattamie | 41 13 38 N | 095 50 58 W |
| Manchester | Locale | 267 | Allamakee | 43 09 40 N | 091 29 14 W |
| Manchester | Locale | 287 | Delaware | 42 28 50 N | 091 27 55 W |
| Manchester | Populated Place | 287 | Delaware | 42 29 03 N | 091 27 20 W |
| Manchester Cemetery | Cemetery | 331 | Decatur | 40 42 29 N | 093 45 36 W |
| Manchester Church of Jesus Christ of Latter Day Saints | Church | 287 | Delaware | 42 29 17 N | 091 27 30 W |
| Manchester City Hall | Building | 279 | Delaware | 42 28 33 N | 091 27 23 W |
| Manchester Dental Clinic | Hospital | 285 | Delaware | 42 29 03 N | 091 26 49 W |
| Manchester Evangelical Free Church | Church | 286 | Delaware | 42 29 02 N | 091 27 31 W |