Warren County
- Ellison, Negro Creek Bridge (HIER WA-2003-1)
- Little York vicinity, Campbell Bridge, spanning Cedar Creek at Sumner Township Road 22 (HAER IL-109)
- Monmouth, Johnson House, 300 East Archer Avenue (HABS IL-26-23)
- Monmouth vicinity, Spring Grove Road Bridge (HIER WA-1997-1)
- Rural Warren County, Illinois Route 116 over Negro Creek (Structure No. 094-0012) (HIER WA-1995-1)
