War took its toll on Sean Gobin. The Rhode Island native enlisted in the Marines during college. Only ten days after being assigned to active duty as a tank officer, he rumbled into Iraq with the U.S. forces who toppled Saddam Hussein. Sean helped seize Baghdad, and later took part in the bloody Battle of Fallujah.

But when he returned to the states in 2005, Sean found it had become difficult to maintain normal relationships. He distanced himself from family and friends. “I didn’t want to be bothered with anybody. So I just unplugged,” he says.

In 2011, Sean was sent to Afghanistan to train local military and police forces. During a resupply mission, his lieutenant lost both legs due to an improvised explosive device blast. That’s when it began to dawn on Sean that he wanted out. “The military is a nonstop assembly line, and [as I went] further down the line I started to see the unraveling of my own personal life and well-being. I couldn’t put my finger on it, but I knew I needed a different life.”

Sean left the military and applied to business school. But he felt like he needed something in between—and he’d always wanted to hike the Appalachian Trail. He convinced his friend Mark Silvers, a fellow Marine, to join him. Together, they decided to make their hike a fundraiser to help injured vets pay for adaptive vehicles.

Starting in Georgia, the two men headed north. They hiked for eight hours a day, for four-and-a-half months. For Sean, it was the time he needed to come to terms with ten years at war. “Your brain has nothing to do but process past experiences,” he says.

“On active duty military, you’re in sensory overload—all day, every day. Being on the trail took my life down to a pace at which I could reflect.”

Along the way, Sean stopped in 35 different towns to hold fundraisers and connect with other veterans, who told of their own transitions from earlier wars. Locals came out in droves to support his hike. “After so many combat deployments, witnessing the horrors of war, you really lose your faith in humanity. You no longer look at people as having default goodness,” Sean says. “The communities along the trail—cheering you on, taking you home, thanking you for your service, asking how they can help—it restores that faith.”

The trail’s transformative effect on his own life inspired Sean to launch Warrior Hike, a transition program for veterans returning home after multiple combat deployments.

Last spring, he organized an Appalachian Trail hike for 13 warrior hikers, inspiring interest from dozens more—including a WWII veteran who would become the oldest hiker ever to complete the trail. Sean envisions treks down the Pacific Crest and Continental Divide trails, too—and for veterans with lower-extremity injuries, even paddling trips of the entire Mississippi River.

“When you get out on the other side, it’s almost like a reset button,” Sean says of the through-hike experience. “You’ve come to terms with what’s happened in the past, and you’re ready to move on.”

This story was written by Andy Isaacson. It originally ran in the 2014 Spring/Summer issue of Land&People magazine.