The 400 Bike Trail is a 22-mile (35 km) rail trail between Reedsburg and Elroy, Wisconsin. It is designed for foot, bicycle, equestrian, snowmobile traffic. It is designated as a multiuse trail, offering recreational access to the routes, and is open to the public.
It is one of four connecting bike trails in west-central Wisconsin that spans approximately one-third of the state. The trail is known for its rural scenery of the Baraboo River which it crosses eleven times. It is part of the larger Wisconsin bike trail system, operated by the state of Wisconsin.
The four connecting west central Wisconsin trails, known as the Bike 4 Trails, going from southeast to northwest are:
The 400 trail connects to the Elroy-Sparta State Trail in Elroy.
The trail headquarters is located in a historic depot in Reedsburg and is open from May 1 through October 31. There is a $5.00 per day fee for use of the trail if one does not have the $25.00 yearly Wisconsin bike trail pass. Bike lights are advisable even on the brightest summer days when going into the long unlit tunnels. Camping, lodging, food, parking, bike rentals and information are available at many points along the trail.
The trail is constructed upon an abandoned Chicago and North Western Railway railroad bed. It is named after the Twin Cities 400 passenger train which traveled from Chicago to Minneapolis/St. Paul in 400 minutes, though the Twin Cities 400 did not travel on the line that was converted to a trail. The trail is not paved but is smooth and covered with packed crushed limestone.