The Mon River Rail-Trail follows the Monongahela River through Fairmont on a former B&O Railroad rail corridor, offering flat, paved cycling and walking along the riverbank. The trail is part of a larger network of rail-trails following the Monongahela and its tributaries, which eventually connects to the Allegheny Highlands Trail and the larger Mon/Ohio River Trail system. For cyclists, Fairmont is a useful waypoint on a longer river trail journey.
The Fairmont section of the trail passes through the riverfront areas of the city and gives good views of the river bridges, particularly the Robert H. Mollohan bridge (the Million Dollar Bridge), which is one of the more striking engineering structures in the area. The trail is accessible from several points in the city; the downtown riverfront area is the most convenient starting point.