The Appalachian Trail is a foot path in the eastern United States extending 2193.1 miles (3529.4 kilometers) ¹ and is therefore dubbed the 2000 miler. The trail generally traverses the crest of the Appalachian Mountains between Springer Mountain in northern Georgia and Katahdin in north central Main.

The path reaches elevations of over 6000 feet in several places with the high point of 6643 feet at Clingmans Dome.

The low elevation on the AT is 124 feet above sea level on the Nature Trail near Bear Mountain Park near the crossing of the Hudson River at Bear Mountain Bridge located in New York state.

The Appalachian Trail traverses fourteen contiguous states and is marked and maintained by thirty-four trail organizations, supervised by the Appalachian Trail Conference, which has it′s headquarters on the trail at Harpers Ferry, West Virginia.

The AT was first proposed in 1921 by Benton MacKay, who was a forester, philosopher, dreamer and frequenter of the mountain in New England. Construction began during the following year near Bear Mountain in New York state.

Then, mostly through the work of Arthur Perkins and Myron Avery, the trail was completed by 1937 between Katahdin and Mount Oglethorpe in Georgia. Later, the site of the southern terminus was relocated to Springer Mountain, ten miles north of Mount Oglethorpe.

In 1968 the Appalachian Trail joined the National Parks System who renamed it the Appalachian National Scenic Trail.

There are numerous shelters on or near this wilderness path and frequently only a day's walk apart. These shelters are crude structures normally built of wood with a few out of stone and are most often open on one side. Some of the shelters have a door and even fewer have a fireplace.

The sleeping berths are also primitive, most of which are a wood frame with a wire mesh covering while several have a plywood covering. In Maine, the berths are made by nailing baseball bat size saplings side by side on the wood frame. All of these shelters may be used by the traveler to rest for the night on a first come, first serve basis.

However, now, much has changed since the days when Tommy Michel began his walk on the AT in 1978. Many of the shelters are far from primitive and there is an overall average of 8.5 miles between shelters, although some are still separated by 30 miles.

The Appalachian Trail is marked with 6-inch-long by 2-inch-wide white paint marks, mostly on trees but also on a few buildings, telephone poles and other structures. These white blazes serve as markers to let hikers know that they are still on the right trail.

There are estimated to be about 165,000 white blazes along the entire Appalachian Trail.

This wilderness path, the Appalachian Trail is the world′s longest continuously marked footpath. ²

In contrast, the two other long distance trails: the Pacific Crest Trail and the Continental Divide Trail, as well as several other North American paths are usually not marked with painted blazes. Instead, they use metal emblems installed in trees and at intersections to keep hikers on track.