Seneca Greenway to Upper Potomac River Trail is a 13.2 mile loop trail located near Germantown, MD that features a river. The trail is primarily used for hiking, walking, nature trips, and birding. 13.2 miles 688 feet Loop birding hiking nature trips walking forest river wild flowers Expand Map Sign up now to see this map! Reviews (0)Photos (0)Recordings (5)No one has reviewed this trail yet. Be the first!