All About the Secret Tunnel Beneath Clingmans Dome

Clingmans Dome is one of the most popular destinations in the Smokies, but few people truly know what lays below! Underneath Clingmans Dome Road, an ornately decorated hidden tunnel stands alone. It’s most commonly referred to as the Thomas Divide Tunnel, but it’s also frequently called the Thomas Ridge Tunnel, the Old Mule Tunnel, or other variations. Although it was once located on a hiking trail, the secret tunnel under Clingmans Dome is now one of the park’s best hidden treasures. Here’s everything you need to know about the hidden tunnel beneath Clingmans Dome:

How it Was Built

clingmans dome tunnelThe secret tunnel under Clingmans Dome was constructed in the 1930s by a group called the Civilian Conservation Corps. This group was created by the FDR administration to provide mostly unmarried, unemployed men with manual labor jobs that related to the conservation and maintenance of government owned land. The men built many roads, trails, bridges, and buildings. The tunnel is made mostly of stone that is locally sourced from boulders and rock veins in the Smoky Mountains and features an ornate archway on either side.

Why It Was Built

Prior to 1935, there was a trail that ran parallel to a segment of the Newfound Gap Road. After the completion of Clingmans Dome Road by the Civilian Conservation Corps in 1935, this trail had to be moved. Instead of routing this trail to cross Clingmans Dome Road, builders constructed it underneath! The tunnel not only kept hikers from having to cross the road, as well as prevented collisions between equestrian traffic and automobile traffic.

Where It’s Located

sunset at clingmans domeThe tunnel is located on a trail believed to be called the Thomas Divide Trail, which used to connect to the Appalachian Trail on the far side of Clingmans Dome. In the 1960s, the Mission 66 initiative aimed to improve infrastructure in the Great Smoky Mountains National Park. One part of this plan was to reroute several old roads, including the Newfound Gap Road, in order to create smoother drives with more scenic views. The Mission 66 initiative eventually led this trail to be moved South, leaving the tunnel standing alone. Upon passing through the tunnel, you’ll find a cliff with a beautiful view where the rest of the trail once stood.

How To Find It

Just because you won’t see this tunnel on a map doesn’t mean it’s impossible to find on foot! To reach the hidden tunnel, simply follow Clingmans Dome Road to the access point. Then, park your car and continue to walk 0.2 miles up the road. When you reach the big stone bridge, head down the hill and you’ll see the tunnel!

The Great Smoky Mountains National Park attracts more visitors than any other national park, so it can be easy to get caught in a crowd. But beyond the bumper to bumper traffic of Cades Cove or the popular trails like Chimney Tops, the park has lots of hidden gems to offer those willing to look. Check out more hidden gems in the Smokies and see what else the Great Smoky Mountains National Park has to offer!