The Potomac Appalachian Trail Club (an authorized park concessioner), maintains six locked, primitive cabins in the park. The cabins are equipped with mattresses, blankets, and cookware. A pit toilet and spring water are nearby. To get information or to make reservations, call PATC at (703) 242-0693 or (703) 242-0315; or write to PATC, 118 Park Street, SE, Vienna, VA 22180.