Runners start the out-and-back course for the Potomac River Run Marathon & Half Marathon near Fletchers Cove and the Potomac Palisades Parkway, just off Canal Road. From there, the race heads northwest along the C&O Canal Towpath, all the way along the river to the half-way turnaround point just past Interstate 495 and Clara Barton Parkway. The half marathon is one out-and-back — the race finishes back at Fletchers Cove — while the full marathon repeats the course a second time.
Note: The course map above provides the approximate route for the race. Though every effort has been made to ensure its accuracy, changes are sometimes made to race routes due to weather conditions, road closures or other circumstances that can require a course to be changed. If you see an error above, email us here.