Appalachian Trail

In 1921, conservationist Benton MacKaye proposed an "experiment in regional planning"—the Appalachian Trail. Work began the following year, and by 1937, the 2,160-mile-long trail was complete. The first person walked its entire length, from Georgia to Maine, in 1948. In recent years, some 100 hikers have repeated the feat every year, including a six-year-old boy, several octogenarians and a blind man with his service animal. The entire trip takes four-to-six months to complete.

The footpath traverses 14 states, eight national forests, and two national parks, crossing 15 major rivers. Elevations range from 6,642 feet at Clingmans Dome in the Great Smoky Mountains to near sea level at the Hudson River in New York.