Section 81 of the Appalachian Trail runs 7.4 miles from Crampton Gap to Turners Gap (Alt US 40). Along the way it passes the Crampton Gap shelter, the Rocky Run shelter, and Fox Gap on Reno Mountain Road.
From I-70: take 15 N., 550 toward Sabillasville/Ft. Ritchie, Turn SLIGHT LEFT onto FORT RITCHIE RD, FORT RITCHIE RD becomes MACAFEE HILL RD, Turn LEFT onto PEN MAR HIGH ROCK RD., Welcome to PEN MAR PARK, MD
http://www.tripleblaze.com/trail.php?c=3&i=1438