Today's episode is bittersweet because we have reached the end of our hike. After three years and 50 episodes, we are wrapping up The Green Tunnel with something a little different. Every episode of The Green Tunnel has focused on some aspect of the history of the Appalachian Trail, but today we're looking forward. What will the AT's future look like? How will the trail evolve? What will the greatest challenges be for the trail we all love?

On today's episode of The Green Tunnel, we are exploring a central reason why hikers head to the Appalachian Trail in the first place, to see wildlife. We'll also talk about how the animals along the trail are changing the way hikers experience the AT and the ecology of the mountains the AT passes through.

What long-distance AT hiker hasn't dreamed of reaching that sign on the summit of Katahdin at the end of their hike? Today, we are headed to the top of the mountain to explore the history of the iconic sign.

The Appalachian Trail winds its way through Appalachia which is a place where people make sense of their world through stories. Stories of their lives in the mountains. Stories of the land and its riches. Stories, both fiction and non-fiction, about their journeys. In this episode of The Green Tunnel, we are exploring the history of writing about the Appalachian Trail.

Did you know a significant number of hikers confess their sins in the logbook in the shelter on Priest Mountain? Why do they do this and what do they confess? Find out on today's Iconic Locations episode.

Benton MacKaye wanted to be sure that anyone who chose to spend a few hours, a few days, or a few weeks on the trail would have the opportunity to really get away from civilization. However, most of the lands MacKaye hoped to route his future trail through were in private hands, owned either by individuals or corporations. If an Appalachian Trail was really going to be built, then its leaders would have to find a way to reconcile their desire to build a trail with the rights of private landowners.

The Delaware Water Gap is one of the most breathtaking spots along the entire Appalachian Trail and has been a favorite subject of landscape painters since at least the middle of the 19th century. It's an important marker for northbound hikers, but it's also a torturous landscape that many hikers call "Rocksylvania."

There is no better way to turn a good hike into a bad hike than taking a wrong turn and hiking miles out of your way. Especially if that means you climbed an extra mountain or two. Today, we are exploring the history of blazing, signing, and mapping the trail from Georgia to Maine.