Iowa - Area of significance: Conservation
| American School of Wild Life Protection Historic District |
| Backbone State Park, Cabin-Bathing Area (Area A) |
| Backbone State Park Historic District |
| Backbone State Park, Picnicking, Hiking & Camping Area (Area B) |
| Backbone State Park, Richmond Springs (Area C) |
| Beeds Lake State Park, Civilian Conservation Corps Area |
| Blackhawk State Park, Black Hawk Preserve (Area B) |
| Blackhawk State Park, Denison Beach Area (Area C) |
| Blackhawk State Park, Wildlife Preserve Area (Area A) |
| Civilian Conservation Corps-Prisoner of War Recreation Hall |
| Darling, Jay Norwood and Genevieve Pendleton, House |
| Decorah Ice Cave |
| Dolliver Memorial State Park, Entrance Area (Area A) |
| Dolliver Memorial State Park, Picnic, Hiking & Maintenance Area (Area B) |
| Dow House |
| Fairport Biological Station Historic District |
| Fish and Game Pavilion and Aquarium |
| Flynn Farm, Mansion, and Barn |
| Fort Atkinson Historic District |
| Geode State Park, Civilian Conservation Corps Area |
| Gull Point State Park, Area A |
| Gull Point State Park, Area B |
| Guttenberg National Fish Hatchery and Aquarium Historic District |
| Holdoegel, Perry C. and Mattie Forrest, House |
| Iowa Lakeside Laboratory Historic District |
| Iowa State Fair and Exposition Grounds Historic District |
| Jones Creek Watershed Historic District |
| Lacey-Keosauqua State Park, Bathing Area (Area C) |
| Lacey-Keosauqua State Park, Lodge and Picnic Area (Area A) |
| Lacey-Keosauqua State Park, Picnic and Custodial Group (Area B) |
| Lake Ahquabi State Park, Bathhouse Area (Area B) |
| Lake Ahquabi State Park, Picnic Area (Area A) |
| Lake Ahquabi State Park, Refectory Area (Area C) |
| Lake Keomah State Park, Bathhouse-Lodge Area (Area A) |
| Lake Keomah State Park, Erosion Control Area (Area B) |
| Lakeside Park Historic District |
| Lansing Fisheries Building |
| Lock and Dam No. 11 Historic District |
| Lock and Dam No. 16 Historic District |
| Lock and Dam No. 19 Historic District |
| MacDonald, Gilmour B. and Edith Craig, House |
| Maquoketa Caves State Park Historic District |
| Mini-Wakan State Park Historic District |
| 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) |
| Shimek, Bohumil, House |
| Springbrook State Park, Civilian Conservation Corps Area |
| Squirrel Hollow County Park Historic District |
| Starker-Leopold Historic District |
| Trappers Bay State Park Picnic Shelter |
| Wallace, Henry, House |
| Wanata State Park Picnic Shelter |
| Wapsipinicon State Park Historic District |
| Yellow River State Forest Fire Tower |
Data from United States Park Service and Wikidata
