The Triple Crown of long-distance hiking in the USA is comprised of the Continental Divide Trail (CDT), Pacific Crest Trail (PCT), and Appalachian Trail (AT). The CDT is the longest of the three.

The CDT was designated as a National Scenic Trail in 1978. It closely follows the United States Continental Divide, which separates the Atlantic and Pacific Watersheds. It starts on the Mexican border in New Mexico, traverses New Mexico, Colorado, Wyoming, Idaho, and Montana, and ends on the Canadian border in Montana. The trail can be hiked South to North or North to South.