Directions:: SEE http://www.washrun.org/dcroutes/archie.html
credit to the Washington Running Club
From Virginia cross over Key Bridge and take a left onto M St. Follow that past the backside of Georgetown University and then around to the right (becomes Foxhall Road). Take a right onto Reservoir Rd, about 1/2 mile (?) you should see the trailhead on the left. If you see Georgetown University Hospital on the right you have gone about a block too far.
Trail Information:: mostly dirt, some nice hills but plenty of flats too. beautifully wooded, runs along a stream part of the way
Miscellaneous Information:: Here's a decent map