Iowa - Area of significance: Industry
| Salisbury House |
| Sandwich-Marseilles Manufacturing Building |
| Schlapp, George E., House |
| Schmitt and Henry Manufacturing Company |
| Schricker, John C., House |
| Sheaffer, Walter A., House |
| Shields Woolen Mill |
| Shores-Mueller Company |
| Sioux City Linseed Oil Works |
| Spaulding Manufacturing Company |
| Spencer, Roswell, House |
| Spring Branch Butter Factory Site |
| State Quarry, Old |
| St. Katherine's Historic District |
| Stoll Building Works |
| Stone City Historic District |
| Valley Mills |
| Vermeer, Gary J. and Matilda, Farmstead |
| Vincent House |
| Walnut Tire and Battery Co.-Globe Publishing Company Building |
| Wapsipinicon Mill |
| Weis, Henry, House |
| Wild, Daniel and Margaret, House |
| Wild Historic District |
| Williams, Seneca, Mill |
| Williges Building |
| Winterset City Park Historic District |
| Witwer Grocery Company Building |
| Zoeller Bros-Independent Malting Co. |
Data from United States Park Service and Wikidata
