The closest legal place is Kansas Rocks, near Fort Scott, Ks. They are usually open on the weekends, and they do charge a fee. If you are looking for unmaintained roads, check the county maps and/or get a DeLorme Atlas and Gazetteer. There are a couple of clubs in the area, Kansas City Jeep Club and KC 4WD. Both of them have web sites and sometimes they allow non-members to tag along. There is also a couple of Facebook groups, I think they are the Northland Jeepers and the KC Southland Jeepers.