Ignore Google Maps directions if heading i57 southbound & take the “Salem exit” instead of the one directly north of Salem that exits into Centralia, IL.
We didn’t know & it was quite a bumpy ride… dislodged a lot of supplies & had to clean up. There was one narrow road along the drive which would be super tight for 2 RVs going opposite ways while heading East off of i57. Also, we didn’t see any state park directional signs between i57 and the Forbes SP entrance sign during the approx 25 min drive & had to guess right or left at a T-intersection when Google maps told us to continue straight & drive through a field.
We left Forbes SP the next morning on a diff route traveling through Salem back to i57 & had no issues.
We were walk-ins during off season in Feb (no h2o nor bathhouse access) & arrived after the office had closed, but were able to pay at 7am the next morning. Floating bridge linking campground to concessions/marina area is partially dismantled & undergoing extensive repairs after mangled from flooding (bit of a detour-walk to get from campground to marina with Concessions/restaurant not open bc off season, but tiny grocery store outside of state park open & selling bundles of firewood for $7). We were told dump & fill stations are open year round. Park office has small but interesting educational area inside & brochures for a lot of diff IL state parks. Very friendly staff!
Tiny grocery store outside of state park, but normal size grocery about 15min away in Salem.
Definitely coming back for a long weekend to hike the trails.