Minn. Stat. § 160.06: TRAIL OR PORTAGE DEDICATION.

Any trail or portage between public or navigable bodies of water or from public or navigable water to a public highway in this state that has been in continued and uninterrupted use by the general public for 15 years or more as a trail or portage for the purposes of travel, is deemed to have been dedicated to the public as a trail or portage. This section applies only to forest trails on established canoe routes and the public has the right to use the same for travel to the same extent as public highways. The width of all trails and portages dedicated by user is eight feet on each side of the centerline of the trail or portage.