The Appalachian Trail (AT) runs from Maine to Georgia, covering 2,181 miles along ridges, through valleys and thick forests, 14 states, and Kevin Gallagher's childhood backyard. As a kid, he was an AT regular, hiking sections of the trail with his family near their home in the Shenandoah Valley of Virginia. It was those day hikes that would turn Gallagher on to the six-month trek of the entire AT.
"I remember standing on the trail and my mom pointed in one direction and said, 'if you walk all the way that way, you'll get to Maine.' Then she turned me around and said, 'if you walk all the way that way, you'll get to Georgia."
Gallagher was only seven at the time, but the moment was definitive.
On April 2, 2005 he set out from Springer Mountain in Georgia and hiked north, arriving at Katahdin, Maine on October 6.
"I sure would have loved to keep going," he said.
Along the way, he took 24 photographs of 24 steps of a section of trail each day. When Gallagher returned home, he had over 4,000 slides. In February 2011 he released "The Green Tunnel," a video that strings together each scanned slide and takes viewers down the epic footpath in under five minutes.