The Soo Line Trail Southern Route is more popularly known as the Soo Line South ATV Trail. The converted rail-trail runs for 105.6 miles in Minnesota between Royalton and the MinnesotaWisconsin state line east of Pleasant Valley. The Soo Line South ATV Trail continues uninterrupted into Wisconsin, here known as Saunders State Trail
, traveling for another 8.4 miles to Boylston Junction near Superior, WI. The entire route, including the Wisconsin portion, is open to motorized use.
This scenic route includes a mix of woods, farmland and trestle crossings on the Kettle River and Birch Creek and includes the Northern Pine Riders ATV Trail. The Soo Line Trail South connects with the 148-mile Soo Line North
ATV Trail, southwest of Moose Lake. In Royalton the rail-trail continues southeast on the other side of US 10; however, this section, known as the Soo Line Recreational Trail
, is open to non-motorized use only.