In case you haven't heard, all state parks are closed in Illinois and Wisconsin due to the coronavirus pandemic. I'm sure it's the same for many of the other parks in the Midwest. Be sure to check the current status before you plan a trip to any of the parks in this area.
https://www.dailyherald.com/news/20200316/illinois-state-parks-and-other-facilities-closed
https://dnr.wi.gov/topic/parks/