The state of Michigan allows dispersed camping anywhere on State Forest Property as long as all rules are followed.
There is no charge for dispersed camping but you must obtain a permit.
In the following link, you will find Minnesota State Parks that offer remote camping. I really like this page. It shows a clickable link of the park, with type of campsite (walk in, backpack, canoe) and the price per night. http://www.dnr.state.mn.us/state_parks/remote_camping_opportunities.html
In Minnesota, the backcountry camper may prefer to stay in the State Forest. Even though the use of designated campsites are encouraged, dispersed camping is permitted. There are no furnished amenities. These campsites are free and no permit is required. http://www.dnr.state.mn.us/state_forests/map.html