Great Falls Half
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About the race
The Great Falls Half is a small, capped field event on the C&O Canal towpath that begins and ends at Great Falls Tavern in Potomac, Maryland on November 21, 2026.
The event offers these distances:
- Half marathon (13.1 miles)
- 10K
- 5K
The course follows the towpath beside the canal and the Potomac River, passing Lock 20, Widewater, Old Angler's Inn and Carderock before returning to the Great Falls area. The surface is crushed stone and packed dirt. The towpath was built for canal mules, so the route is very nearly flat with a gentle downstream drop and a matching return.
Starts are staggered so runners converge on the finish together. The trail remains open to hikers and cyclists during the event; participants are asked to keep right, pass on the left, and call out when passing. Live GPS tracking is provided on Geo.Racing so others can follow runners along the towpath.
Finish-line provisions include scratch-made donuts and pizza. The event uses chip timing and provides race shirts, finisher medals, aid stations on the towpath, and awards for the top three men and women in each distance. The field cap is a condition of the National Park Service permit for the event. Visit the organization's website for the most recent information.