There's a state-run offroad recreation area in St. Louis County, on Hwy 135 just east of Hwy 53 near Gilbert and Biwabik. It's open to the public and has designated trails for dirt bikes, 4-wheelers, and trucks. I can't remember the name of the place, but a friend drove his Jeep Wrangler up there for the day last year and had a blast. The cost was very reasonable, he said, and a lot of people used the facility the Saturday he was there. I don't think I'd want to run my Expy in there in case something broke, but I'd certainly haul the two Big Bears up there to have some fun.