Nearly everyone who has visited the Great Smoky Mountains National Park is familiar with Clingmans Dome, located along the state line of Tennessee and North Carolina.
Completed in 1959, the Clingmans Dome observation tower is the highest point in the Smoky Mountains. It stands over 6,000 feet tall and offers 360-degree views.
On clear days, guests can see almost 100 miles in any direction from the top of the tower. Sadly, according to the National Park Service, air pollution usually limits the views to only 20 miles.
Still, it’s easily one of the most visited landmarks in the national park.
But have you heard of the secret abandoned hiking tunnel below Clingmans Dome?
Area Deals and Discounts
Subscribe to our newsletter and we will instantly deliver the best area discounts to your inbox.
Is there a secret tunnel under Clingmans Dome?
There’s an old tunnel near Clingmans Dome, but it’s not exactly “under” it.
You won’t readily find this old hiker’s tunnel on Google maps. It pre-dates the tower itself.
It’s a former hiker’s underpass most commonly known as the Thomas Divide Tunnel.
But it is also referred to as the “Thomas Ridge Tunnel”, the “Old Mule Tunnel” or simply “The Hiker’s Tunnel”.
The tunnel was constructed in the mid to late 1930s by a group of young men known as the Civilian Conservation Corps. The tunnel is made of locally sourced stone and features an ornate archway on either side of the road.
According to the Great Smoky Mountains Association, it is speculated that the tunnel is a relic of a section of the Thomas Divide Trail that connected the Appalachian Trail on the far side of Clingmans Dome Road.
The completion of Clingmans Dome Road required rerouting the trail. One option could have been rerouting the trail to cross Clingmans Dome Road on the roadbed. However, engineers decided to build the tunnel under the road.
Alternatively, the Association also speculates that it’s possible the tunnel was constructed for equestrian use. Some records show that it was used as a mule trail tunnel.
What was the Mission ’66 initiative?
In the 1960s, the tunnel was cut off from the original trail and stranded due to the Mission ’66 initiative.
It was the initiative’s mission to improve infrastructure across the entire national park system.
That led to the rerouting of several old roads to improve overall driving conditions, including the upper section of Newfound Gap Road. This rerouting cut off the old trail, forcing the trailhead to be relocated further south.
That’s why you won’t happen upon it unless you’re looking for it. It’s no longer part of any regular path or hiking trail.
It simply leads to a cliff with a beautiful view where the other side of the trail once existed.
Today, it serves as one of the hidden gems around the Smoky Mountains that hikers enjoy finding.
It’s an iconic landmark, a forgotten relic that is fun to discover, like the old springhouse from the Voorheis estate or relics from the ghost town in the Elkmont area.
Where is the secret tunnel in Clingmans Dome?
But just because you are unlikely to happen upon this secret tunnel on accident doesn’t mean it’s difficult to find if you know where to look.
To find it, take Clingmans Dome Road until you reach the access gate. From there, simply park your car and walk approximately 0.2 miles up to the far side of Clingmans Dome Road.
When you reach the large stone bridge that you’d normally drive right across from your car, walk down the hill. Lo and behold, you will spot the tiny abandoned tunnel.
Pro-tip: It might be a bit easier to access in the off-season when you know traffic won’t be an issue. Clingmans Dome Road usually closes from December-April.
This will also make it harder to miss the gate landmark since the gate will be blocking vehicle access.
Did you know about this secret tunnel in the Smokies of TN and NC? What are some of your favorite secret spots in the park? Let us know in the comments below.