Iowa - Area of significance: Politics/Government
| Lock and Dam No. 16 Historic District |
| Lock and Dam No. 19 Historic District |
| Lucas County Courthouse Square Historic District |
| Marshalltown Downtown Historic District |
| Mason City Engine House No. 2 |
| Maynard Town Hall and Jail |
| McColl, Anthony M., House |
| McWaid, Job A. and Rebecca E., House |
| Memorial Building |
| Miller, Justice Samuel Freeman, House |
| Mini-Wakan State Park Historic District |
| Mitchell County Courthouse |
| Montauk |
| Moorehead Stagecoach Inn |
| Municipal Building |
| Municipal Building |
| Noble-Kendall House |
| Old Allamakee County Courthouse |
| Old Capitol |
| Old City Hall |
| Old Harrison County Courthouse |
| Osceola Commercial Historic District |
| Perry and Brainard Block |
| Pikes Point State Park Shelter and Steps |
| Pillsbury Point State Park |
| Pilot Knob State Park, Amphitheater (Area 4) |
| Pilot Knob State Park, Observation Tower (Area 2) |
| Pilot Knob State Park, Picnic Shelter (Area 3) |
| Pilot Knob State Park, Portals (Area 5a) |
| Pilot Knob State Park: Portals in Area 5b |
| Pilot Knob State Park, Trail Area (Area 6a-6c) |
| Plum Grove |
| Plymouth County Courthouse |
| Price, Hiram/Henry Vollmer House |
| Public Square Historic District |
| Red Oak Firehouse and City Jail |
| Rogers-Knutson House |
| Sample, Hugh W. and Sarah, House |
| Scott County Jail |
| SERGEANT FLOYD |
| Spencer, Roswell, House |
| Springbrook State Park, Civilian Conservation Corps Area |
| Studebaker Corporation Branch Office Building |
| Tabor Antislavery Historic District |
| Tama County Jail |
| Temple, Marcellus Luther and Julia Protzman, House |
| Thedinga, J. H., House |
| Todd House |
| Trappers Bay State Park Picnic Shelter |
| US Post Office-Iowa Falls |
| Valley Junction-West Des Moines City Hall and Engine House |
| Walsh Flats/Langworth Building |
| Wanata State Park Picnic Shelter |
| Washington Junior High School and Jefferson Grade School |
| Waverly East Bremer Avenue Commercial Historic District |
| Weaver, James B., House |
| Wells-Stubbs House |
| Wilson Building |
| Wilson, US Senator James F., House |
| Woodbury County Courthouse |
Data from United States Park Service and Wikidata
