22½ annual Potomac River Run Marathon & Half

The Potomac River Run Marathon & Half begins and ends at Fletcher's Cove in Washington, D.C., offering marathon and half-marathon distances along the C&O Canal Towpath. This spring trail race coincides with World Laughter Day, and its organizers describe it as the most accessible trail marathon and half in the United States. The route keeps participants on the towpath, avoiding city streets, creating a canal-side trail atmosphere rather than a large urban marathon feel. All finishers receive a Dan Kain Trophies medallion. Awards are presented immediately after each runner completes the race. The recovery zone features refreshments on the towpath, followed by a post-race picnic. The event is also a component of the SHF Grand Prix; runners completing three SHF half or full marathons in the series are eligible for a cash prize. FindMyMarathon voters selected it as Washington, D.C.’s leading marathon in a poll. The series also features a subsequent 23½-mile event held in remembrance of Dean Shulman and Wendy Martinez.