Potomac Heritage Trail Algonkian Park to Great Falls is a 20 mile lightly trafficked out and back trail located near Great Falls, VA that features a river. The trail is rated as difficult and primarily used for hiking and mountain biking.
Park at Roosevel Island parking lot.
Easy trail. Great with dogs. A few places they can get in easy water.
Great trail with river crossings and steep rock steps. Culminates with great view of the Potomac.
Trails is getting more and more difficult as it's close to Chain Bridge, due to a lots of rock hopping and climbing. So make sure, get a good hiking shoe, great scenery of the Potomac river though. I do the loop thru the C&O canal back to George Town, Roosevetl Island for a total of ~ 8 miles.
Good moderate trail.