Potomac

Added by John Querry:
The park on the Virginia side of the GW canal and the Seneca Breaks is owned by Northern Virginia Regional Park Authority. It is just down stream of the Lowes Island Golf Course. Officially, the park has no name, but it is commonly know as 'the park at the end of Seneca Road'.
For paddlers looking for an aerobic river access hike while carrying their boat, they can park outside the park gate at the end of Seneca Road. Then carry down the paved road, pass by a utility dirt road gate on your right, to where the road takes a sharp left turn at the intersection of the Potomac Heritage National Scenic Trail. Continue straight onto a dirt trail for about 500' along the ancient Seneca Road bed to the GW canal shore. It's about 1 1/4 mile and a 300' hill carry from the gate to the put in. To paddle all of the rapids in the Canal loop, the best take out is about 500' past the Colonial Pipeline right of way. The right of way is easily recognizable from the river. It's a 100' wide swath on both sides of the river that is completely void of large trees. The trail at the take out connects back to the Potomac Heritage Trail which is also the dirt utility road you saw while carrying to the put in. So it, in turn, takes you back to Seneca Road.
Be prepared for a work out: it's a 3 mile, up hill carry from the take out to the park gate. That's about 4 1/4 miles of total carrying; but if you live on the Virginia side of the these rapids, it will save you about 2 1/2 hours of rush hour driving to get to and from Violets Lock.