Appalachian National Scenic Trail
Running 2160 miles along the ridges of the Appalachians, in Eastern United States, the Appalachian Trail traverses some 14 states, from Springer mountain in Georgia to Katahdin 
mountain in Maine.
The AT lies within a day's drive of over half the Country's population. It traverses the most densely populated areas of the country. Still, it is possible to find solitude in the midst of the urban landscape. Due to it's proximity to a large population, the AT attracts the largest number of people to attempt a Thru-hike. Each spring some 3000 to 4000 make the attempt. Of those that start, only about 10% complete the trek.
National Park Service- Appalachian Trail Webpage
Appalachian National Scenic Trail NPS Project Office
c/o Harpers Ferry Center
P.O. Box 50Harpers Ferry, WV 25425-0050
Phone: 304-535-6278
The Appalachian Trail Conservancy is the primary organization managing the Appalachian trail. It is responsible for coordinating the many different trail clubs, acquiring land and easement rights for land that the AT crosses. The conference maintains an online store where you can purchase books, guides, maps and other material concerning the Appalachian Trail.
APPALACHIAN TRAIL CONFERENCE
799 Washington St
PO Box 807
Harpers Ferry, West Virginia 25425-0807
Phone: (304) 535-6331