A tough out and back on the Appalachian Trail in the G.R. Thompson Wildlife Management Area.
Take Fire Trail Road and start your run at the parking area (labeled in the map). The trail puts you directly onto the AT, where you will turn right (southbound) to start the run (or hike). You'll stay on the AT for roughly 3.5 miles down to the Trillium Trail Parking area. At that point, turn around and head back. (7 miles total)
Its dog friendly, so don't forget to bring along your pup!