MY suggestion would be to contact your DCNR dept and ask them where its legal and what all is needed to LEGALLY ride atv's
they should have maps and info, that can get you safe places to ride, the tourism dept would be a big help here,a s I know ALL states offer that stuff trying to lure folks to visit and spend money LOL
I live in the SW metro burbs. Not really any good public options for anything close. Tri-county atv park is your closest option, but I've never been there because I'm more of a trail guy. Closest decent trail option is Red Top trail, near Mille Lacs Lake. Best trail I've ridden in the state is Spider Lake, just a little further to get to.