Iowa... There is a nice place about 20 min south of Cedar Rapids called 600 Acres(Hoosier Creek). This is a nice place for stockers and modified people to play. Hardcore drivers may find it a bit lacking tho.
Indiana... BADLANDS!! This place is great for stockers to hardcore rock crawlers. It is about an hour north of Indy in a town called Attica. BADLANDS
Wisconsin... Up north is a place called "The Pipeline". It borders the Nicolet National Forest and has something for everyone, from rock crawling to mud holes that will swallow a truck sitting on 44s.