Clingmans Dome

The secret tunnel under Clingmans Dome that you never knew existed

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?

Read Also: Clingmans Dome controversy, the tower that weathered a media storm

Clingmans Dome with ramp
The Clingmans Dome observation tower is an iconic landmark, but it was once a source of controversy. It’s located along the state line, but the visitor center is on the North Carolina side (photo by Marie Graichen/TheSmokies.com)

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.

Clingmans Dome Tunnel
The tunnel is not difficult to find, although it is no longer part of the main trail (photo by James Overholt/TheSmokies.com)

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.

Read Also: Where is the House of the Fairies in Gatlinburg? A landmark lost to time

A look inside the Clingmans Dome tunnel
The tunnel has been cutoff from the main trail, but visitors can still find it if they know where to look (photo by James Overholt/TheSmokies.com)

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.

10 things you didn’t know about Clingmans Dome

If you’ve ever heard of the Great Smoky Mountains, you’ve probably heard of Clingmans Dome.

Being the highest point in the most visited national park will grant you that kind of notoriety.

But with great fame comes great curiosity. Below we answer some of the most commonly asked questions about this iconic landmark to help you plan your visit.

1. What is Clingmans Dome?

Clingmans Dome is the tallest mountain in the Great Smoky Mountains National Park. It’s a very popular park destination and offers one of the best views of the Smokies.

It also has an observation tower at its summit, which was built in 1959 as part of the Mission 66 program, an effort by the National Park Service (NPS) to attract more visitors to national parks.

At the top of the tower (on a clear day), guests can see a 360-degree view of the Smoky Mountains, spanning over 100 miles. It’s a great spot to watch sunrises and sunsets.

Clingmans Dome Visitors Center
The Clingmans Dome Visitor Center is located on the North Carolina side (photo by Marie Graichen/TheSmokies.com)

2. Is Clingmans Dome in North Carolina or Tennessee? 

This is one of the most commonly asked questions about Clingmans Dome, and the answer might just surprise you.

Clingmans Dome is actually located along the state line, so half of it is in North Carolina and half is in Tennessee.

The visitor center is located on the North Carolina side.

3. How high is Clingmans Dome?

Clingmans Dome is the highest point in the Great Smoky Mountains National Park at 6,643 feet.

This makes it the highest peak in Tennessee and the third-highest point east of the Mississippi.

Mount Mitchell in North Carolina wins the title of the highest point east of the Mississippi, coming in at 6,684 feet.

Clingmans Dome
The walk to the top of the observation tower is a steep incline (photo by Marie Graichen/TheSmokies.com)

4. How difficult is the Clingmans Dome hike?

Clingmans Dome Road, which is open from April through late November, offers the easiest way to get to the trailhead.

The road is a seven-mile drive and ends in a large parking area.

The parking lot can fill quickly, so arriving early is advisable.

From there, it’s a half-mile hike to the top of the observation tower. This hike is considered moderate in difficulty. The road is paved, but the incline is very steep. If you aren’t an avid hiker, prepare to take a couple of breaks to catch your breath.

Unfortunately, according to the NPS, the trail to the tower is too steep to be wheelchair accessible. Pets and bicycles are not permitted.

Of course, if you choose to hike to Clingmans Dome during the winter, the hike becomes much longer and more difficult, but it is also less crowded.

The popular Forney Ridge Trail is also found between Clingman’s Dome and Andrews Bald.

If you hike it in the winter, be prepared for snowy or icy conditions.

5. Is Clingmans Dome open year-round? 

Yes, Clingmans Dome is open year-round, including at night. Though the dome is open year-round, Clingmans Dome Road typically closes from December to late March and under certain weather conditions.

If you’re curious to see what the conditions are like at the top before you get there, you can always check out the live feed.

Click here to see the webcam.

6. Is Clingmans Dome free?

Clingmans Dome is part of the Great Smoky Mountains National Park, which means yes, it is free!

Why is the Great Smoky Mountains National Park free? You can thank us Tennesseans and our deep and abiding distrust of the federal government.

Read Also: Why the Great Smoky Mountains National Park is free and others are not

A sign for the Appalachian Trail
The Appalachian Trail crosses Clingmans Dome (photo by Marie Graichen/TheSmokies.com)

7. Is Clingmans Dome part of the Appalachian Trail?

The Appalachian Trail crosses Clingmans Dome, marking the highest point along the 2,144-mile journey.

Save that little nugget of information for your next trivia night!

8. How is the drive to Clingmans Dome? 

Clingmans Dome Road is seven miles long and offers the most accessible way of accessing the tower (when it is open for the season).

The road is curvy but not terribly steep. If you are familiar with mountain roads, it will seem par for the course. It’s nothing like the Tail of the Dragon.

Read Also: 6 tips for riding The Dragon: The most dangerous, curvy highway in TN

A view from Clingmans Dome observation deck
The view from the top is especially good if you hike on a clear day (photo by Marie Graichen/TheSmokies.com)

9. Why is it called Clingmans Dome?

According to “The Origin of Certain Place Names in the United States”, the mountain was called Smoky Dome by American settlers until the late 1850s, when it was renamed after Confederate general, Senator Thomas Lanier Clingman.

Some sources claim that Clingman argued that Smoky Dome was the tallest in the region.

It was later determined that Mount Mitchell was about 40 feet taller.

Read Also: The controversy of Clingmans Dome: The observation tower that weathered the media storm

10. How is the weather at Clingmans Dome?

This, of course, is completely dependent on the time of year when you visit. But, keep in mind that precipitation and cold temperatures are very common at higher elevations.

In fact, temperatures at the top of the dome can easily be 10-20 degrees cooler than areas down below. According to the NPS, the cool, wet conditions on the summit make the spruce-fir forest that grows there a coniferous rainforest.

No matter when you’re visiting this observation tower, it’s smart to bring layers and a jacket and be prepared for any type of weather.

Bonus tip: There’s a secret tunnel below Clingmans Dome

Finally, did you know there’s a tunnel below Clingmans Dome that pre-dates the tower itself?

It’s a former hiker’s underpass most commonly known as the Thomas Divide Tunnel, but it is also occasionally referred to as the “Thomas Ridge Tunnel”, the “Old Mule Tunnel” or simply “The Hiker’s Tunnel”.

In the 1960s, the tunnel was cut off from the original trail, so you won’t happen upon it unless you’re looking for it. 

It’s no longer part of any regular path or hiking trail and simply leads to a cliff with a beautiful view where the other side of the trail once stood.

Read Also: The secret tunnel under Clingmans Dome you never knew existed

Have YOU hiked to the tallest point in the Smokies? Let us know in the comments!

View the web story version of this article here.