The ADT comprises 6,800 miles (10,944 km) of trails, though this includes a loop in the Great Plains and Midwest where the trail splits and becomes two parallel trails. It is possible to walk from coast to coast using only 5,000 miles (8,000 km) of trail. Horses and bicycles are allowed on most segments of the trail.
Parts of the trail runs parallel to the Lincoln Highway, which was the first transcontinental highway.
The official termini are:
- Limantour Beach at Point Reyes National Seashore in northern California
- Cape Henlopen State Park in Delaware
The ADT passes through the following states:
- District of Columbia
- West Virginia
The ADT passes by several major cities which are probably good points of entry. A few of the cities on/near the ADT are:
- 1 San Francisco
- Carson City
- Denver (Going east, the trail splits near Denver)
- Kansas City
- Des Moines
- St. Louis
- Near Chicago
- Cincinnati (Going west, the trail splits near Cincinnati)
- Harper's Ferry (The Appalachian Trail also passes through Harper's Ferry)
- 2 Washington, D.C.
The following long-distance walking trails connect or come within close proximity to the ADT:
- Appalachian Trail: A north-south trail that stretches from Georgia to Maine. Connects to the ADT near Harper's Ferry, WV and possibly other points.
- Continental Divide Trail: A north-south trail that crosses the contiguous U.S. along the continental divide. The ADT joins the CDT from Argentine Pass on the border of the White River and Arapaho National Forests in Colorado to the Collegiate Peaks Wilderness.
- North Country National Scenic Trail: A 4,600-mile (7,400-km) walking trail that crosses the northern Midwest from New York to North Dakota. The NCT connects to the ADT from Chesterhill, Ohio west to Milford, Ohio.
- Pacific Crest Trail: A north-south trail that stretches from Canada to Mexico. Crosses the ADT in Northern California just west of Lake Tahoe near Squaw Valley .