o. There's no formal thru-hiking registration system. But, let friends and family know where you are, what your itinerary is, and your “Trail name.” The A.T. passes through numerous state and national parks, forests and public lands, a few of which require permits, fees, or reservations to stay overnight in shelters or campsites. In some cases, the reservation system is different for long-distance hikers. You need to acquire a backcountry permit for the Great Smoky Mountains National Park in advance of arriving; northbound thru-hikers are encouraged to purchase a Great Smoky Mountains National Park AT backcountry permit just before leaving home.