Like the people who hike it, the Appalachian Trail is always moving.
Although Tuesday marks the 75th anniversary of its completion, the nearly 2,200-mile path from Georgia to Maine is never really finished.
In the decades since the original path was built, 99 percent has been relocated or rebuilt, and transferred to public ownership. That means the trail and some 250,000 contiguous acres are better protected from development.
Mark Wenger is executive director of the Appalachian Trail Conservancy in Harpers Ferry. He says that as desirable land becomes available, it will continue to shift.
Wenger says the relocations and rebuilding have also made the path itself more sustainable.
It was originally routed straight up and down many mountains, which worsened erosion and made hiking much harder.