| Property | Address | City | Date Listed |
|---|---|---|---|
| Bellefountain Bridge | Ashland Ave. over Des Moines River | Tracy vicinity | 5/15/98 |
| Eveland Bridge | Fulton Ave. over Des Moines River | Oskaloosa vicinity | 5/15/98 |
| North Skunk River Bridge | Co. Rd. G13 over North Skunk River | New Sharon vicinity | 5/15/98 |
| Alsop Carroll House | 1907 A Avenue East | Oskaloosa | 11/09/1988 |
| Berry Dr. William E. and Ethel Rosenberger House | 116 Rosenberger Ave. | Oskaloosa | 03/29/1996 |
| Conover Thomas J. House | 1010 N. Market Street | Oskaloosa | 03/28/1996 |
| Edmundson Park Historic District | Jct. of 11th Ave. W and Edmundson Dr. | Oskaloosa | 9/27/07 |
| Forest Cemetery Entrance | Jct. of N. 9th Street and J Ave. E. | Oskaloosa | 12/13/1991 |
| Gibbs E. H. House | William Penn College Campus N. Market Extension | Oskaloosa | 12/13/1991 |
| Hoffman Phil House | 807 High Ave. E. | Oskaloosa | 12/13/1991 |
| Iowa Yearly Meeting House--College Avenue Friends Church | 912 N. C Street | Oskaloosa | 03/29/1996 |
| Johnson William A. and Ida C. House | 307 College Ave. | Oskaloosa | 03/28/1996 |
| Klose Dr. William H. and Mae R. House | 1002 Penn Blvd. | Oskaloosa | 03/29/1996 |
| Lake Keomah State Park Bathhouse--Lodge Area (Area A) | Off IA 371 S of jct. with IA 92 | Oskaloosa | 11/15/1990 |
| Lake Keomah State Park Erosion Control Area (Area B) | Off IA 371 S of jct. with IA 92 | Oskaloosa | 11/15/1990 |
| Lamberson Jack House | 511 N. Park Ave. | Oskaloosa | 11/09/1988 |
| Lincoln School | 911 B Ave. W. | Oskaloosa | 12/13/1991 |
| Mahaska County Courthouse | Market Street and 2nd Ave. | Oskaloosa | 07/02/1981 |
| McMullin Maj. James W. House | 403 1st Ave. E. | Oskaloosa | 04/11/1985 |
| McNeill, W.A., House | 1282 C Ave. E. | Oskaloosa | 10/21/1999 |
| Nelson Daniel House and Barn | SR 1 | Oskaloosa | 11/20/1974 |
| Oskaloosa City Hall | Jct. of S. Market Street and 2nd Ave. E. NE corner | Oskaloosa | 12/13/1991 |
| Oskaloosa City Park and Band Stand | City Park | Oskaloosa | 07/28/1983 |
| Oskaloosa City Square Commercial Historic District | Roughly bounded by A Ave. E N. and S. Second Street Second Ave. E and N. and S. A Street | Oskaloosa | 04/10/1986 |
| Oskaloosa Fire Station | 109--111 2nd Ave. E. | Oskaloosa | 12/13/1991 |
| Oskaloosa Monthly Meeting of Friends Parsonage | 910 N. C Street | Oskaloosa | 03/29/1996 |
| Oskaloosa Public Library | Jct. of Market Street and 2nd Ave. W. SW corner | Oskaloosa | 12/13/1991 |
| Paradise Block Historic District | 402 406 408 410 414 418 and 510--714 High Ave. E. | Oskaloosa | 12/13/1991 |
| Penn College Historic District | 201 Trueblood Ave. | Oskaloosa | 04/04/1996 |
| Pierson--Betts House | 815 Penn Blvd. | Oskaloosa | 03/28/1996 |
| President's Cottage | 425 College Ave. | Oskaloosa | 03/28/1996 |
| Rock Island Passenger Depot | Rock Island Ave. between 1st and 2nd Sts. | Oskaloosa | 10/30/1989 |
| Seeberger-Loring-Kilburn House | 509 High Ave. E. | Oskaloosa | 07/14/1983 |
| Shoemake John H. House | 116 2nd Ave. W. | Oskaloosa | 03/22/1984 |
| Smith-Johnson House | 713 High Ave. E. | Oskaloosa | 11/09/1977 |
| Spring Creek Friends Cemetery | Jct. of Osburn Ave. and 235th Street | Oskaloosa | 03/29/1996 |
| Spring Creek Meeting House | --H Street Mission 207 N. H Street | Oskaloosa | 03/28/1996 |
| Spurgin Residence | 313 College Ave. | Oskaloosa | 03/28/1996 |
| St. James Episcopal Church | Jct. of 1st Ave. and S. 3rd Street SW corner | Oskaloosa | 12/13/199 |
| Stock Judging Pavilion Southern | Iowa Fairgrounds | Oskaloosa | 04/12/1984 |
| Stokes Dr. Ella House | 416 W. College Hill Ave. | Oskaloosa | 03/29/1996 |
| Stranahan Prof. Edgar H. and Irene D. House | 1001 Gurney Street | Oskaloosa | 03/28/1996 |
| Ulysses Simpson Grant Elementary School | 715 B Ave. E. | Oskaloosa | 12/10/08 |
| Vandfer Wilt Farmstead Historic District | 1345 IA 163, Black Oak Twp, Sec 22, T26N, R17W, SW of Ne | Leighton | 01/08/2004 |
| Voorhees John K. House | NW of Oskaloosa on IA 163 | Oskaloosa | 03/05/1982 |