The George S. Mickelson Trail is a rail trail in the Black Hills region of South Dakota. The main trail route extends 108.8 miles (175.1 km), from Edgemont to Deadwood, with approximately nine miles of additional branch trails, including a three mile (5 km) paved link from Custer to the Custer State Park completed in 2007. Intermediate points along the route include the towns of Custer and Hill City, and a short branch provides access to the city of Lead.
The trail is maintained by the South Dakota Game, Fish and Parks Commission. The first segment of the trail was opened in 1991, and the entire route was completed in 1998, and is the first rails to trails project in South Dakota. The trail is named after George S. Mickelson, the South Dakota governor who helped spearhead the project.