Two women walk from the town of Harpers Ferry, W.Va., onto the Appalachian Trail on Aug. 1. Like the people who hike it, the Appalachian Trail is always moving. Technically, Tuesday marks the 75th anniversary of its completion, but the 2,180-mile path stretching across 14 states from Springer Mountain, Ga., to Katahdin, Maine, is never really finished. (Associated Press)

Two women walk from the town of Harpers Ferry, W.Va., onto the Appalachian Trail on Aug. 1. Like the people who hike it, the Appalachian Trail is always moving. Technically, Tuesday marks the 75th anniversary of its completion, but the 2,180-mile path stretching across 14 states from Springer Mountain, Ga., to Katahdin, Maine, is never really finished. (Associated Press)