0.0 -- Start (Colvin Run Mill)
0.1 -- Cross Leesburg Pike (Route 7) at Carper’s Farm Way
0.15 -- Left at wooden posts, 45 degree angle into new woods
o.6 -- At three-slat fence, right onto gravel road
1.1 -- Cross Brown’s Mill Road, on bridge over Difficult Run
1.1 -- right on asphalt path. Stay right.
1.7 -- right on crushed gravel trail toward Dulles Toll Road
1.8 -- cross under Dulles Toll Road
2.0 -- cross Difficult Run on "fair-weather crossing", continue on gravel
2.1 -- hard left turn below first houses on right; cross stream
2.4 -- ascend bluff on gradual incline
2.5 -- cross small stream on foot bridge
3.2 -- athletic field
3.4 -- right on W&OD
3.5 -- cross Hunter Mill Road
3.9 -- cross Buckthorne Lane
5.2 -- cross under Dulles Toll Road
5.4 -- all-weather drinking fountain at Sunrise Hills Road
5.6 -- right, Michael Farraday Drive
5.x -- fast-food eateries and restrooms at Wiehle Ave. & W&OD trail, 1 block off loop
5.65 -- junction with Colvin Run Trail, rear parking lot of #1807 M. Farraday
follow white-blazed posts with horseshoes carved on them for next 4 miles
6.6 -- ford small stream; bear right (not sharp right)
6.9 -- at summit of hill, skirt athletic field
7.3 -- ford small stream, climb steep hill
7.7 -- turn right, cross athletic field, to white posts on descending gravel trail
8.x -- restrooms in valley in season, 0.3 miles west of Hunter Mill Rd.
8.8 -- cross Hunter Mill Road
9.9 -- left, Carper’s Farm Way
9.95 -- cross Leesburg Pike
10.05 -- Colvin Run Road to finish