There are 2 former lookout sites registered in Illinois. The most recently registered former lookout site is Bald Knob Lookout Site (Hardin County) (US 2065, IL 2), added on January 8, 2021.
| Lookout Name | NHLR Registry Number | Available for Rental | Visit Reports |
| Bald Knob Lookout Site (Hardin County) | US 2065, IL 2 | ||
| Bald Knob Lookout Site (Union County) | US 2061, IL 1 |