The George S. Mickelson Trail is 109 miles long. It starts in Deadwood, SD and ends near Edgemont, SD. It was original used as a railroad, but is now a very popular path for walking and biking, among other outdoor activities. There are 1`5 different trailheads, many converted railroad bridges and 4 rock tunnels.
All 4 tunnels are located near the Mystic/Rochford area. Tunnel D is just north west of the Rochford Trailhead, Tunnel C is in between Rochford Trailhead and Mystic Trailhead, and Tunnel A and Tunnel B are just south of Mystic Trailhead. The are all located within a 14 mile area and can easily be visited on the same biking trip.
The area is very beautiful in the Spring and Summer, with many varieties of wild flowers along the trail. If you have a chance to visit it is well worth it.
For a map of the entire George S. Mickelson Trail, click here.