The Zion-Mount Carmel Tunnel is one of the highlights of Zion National Park – but there are some things that you need to know about it – especially if you have a larger vehicle like an RV or trailer.
It looks like a quick scenic drive on the map. But it’s actually one of the most unique — and sometimes confusing — drives in any U.S. national park.
I’ve driven it myself, and here’s the thing most people don’t realize: if you’re in the wrong vehicle, arrive at the wrong time, or don’t understand the rules, your entire route through Zion (and even to places like Bryce or the Grand Canyon) can fall apart fast.
So here’s exactly what to expect — including restrictions, permits, routes, and the mistakes to avoid.
A Quick Look at the Tunnel
Construction of the Zion-Mount Carmel Tunnel began in the late 1920s and was completed in 1930. When it was dedicated on July 4, 1930, it was the longest tunnel of its type in the United States. The project, including building the Zion-Mount Carmel Highway, cost $1,896,000 – a huge sum at the time.
A few quick facts:
Length: 1.1 miles
Elevation gain: 800 feet
Distance from visitor center: ~5 miles
The tunnel — along with the Zion-Mount Carmel Highway — provides direct access between Zion, Bryce Canyon, and the Grand Canyon.
However, there are complications if your vehicle is ‘large’.
Why the Tunnel Is a Big Deal for Drivers
The biggest issue? Size.
Before 1989, large vehicles like RVs, buses, and trailers were involved in increasing numbers of accidents and near-misses inside the tunnel.
A Federal Highways Administration study found that large vehicles couldn’t safely navigate the tunnel’s curves without crossing the center line.
So the National Park Service introduced traffic control — and that’s still how things work today.
When can standard vehicles go through the Zion – Mt Carmel Tunnel?
If you’re in a normal passenger vehicle, you’re good. The tunnel is open 24 hours a day, 7 days a week. No permit is needed.
Oversized Vehicles (Until June 6, 2026)
You’ll need a permit if your vehicle is ≥ 7 ft 10 in wide (2.4 m) OR ≥ 11 ft 4 in tall (3.4 m).
The permit costs $15 (this is in addition to park entry fee). There are no discounts – it’s same price for everyone. It’s valid for 2 trips within 7 days (same vehicle). You pay it at the entrance station before proceeding to the tunnel.
The permit is used to pay for rangers to stop traffic and convert the tunnel to one-way. Rangers are stationed at both ends and stop the traffic at one end so larger vehicles can drive in the middle of the road, safely navigating the turns.
There are time restrictions.
Large vehicles allowed 8:00 am – 4:30 pm only. The last permit issued at 4:15 pm. Plan at least 15 minutes to reach the tunnel from entrances.
If you have a large vehicle, you cannot travel through the tunnel between 4:30pm and 8:00am.
Oversized Vehicles (Starting June 7, 2026)
New restrictions mean that vehicles exceeding size or weight limits will NOT be allowed at all on the Zion-Mt. Carmel Highway between Canyon Junction and the East Entrance. This applies to the entire stretch — not just the tunnel.
If your vehicle is too large, you’ll be turned around at the entrance.
Vehicle Size Limits (Know This Before You Go)
Single Vehicles (No Trailer)
Length: 35 feet 9 inches (10.9 m)
Width: 7 feet 10 inches (2.39 m)
Height: 11 feet 4 inches (3.45 m)
Weight: 50,000 pounds
Combined Vehicles (With Trailer)
Total length: 50 feet
Trailer max: 26 feet (hitch to rear axle)
Width: 7 feet 10 inches
Height: 11 feet 4 inches
Weight: 50,000 pounds
⚠️ Important: Measurements include mirrors, AC units, bike racks, and attachments.
Limited Exceptions
The only exceptions are:
You can park in the large vehicle lot at the visitor center if space is available.
If you have a pass for Zion Lodge (so you can drive to the lodge).
If you’re driving the Zion Canyon Scenic Drive when the shuttle is not running.
If you’re camping at Watchman or South Campground.
Note that none of these exceptions give you access to the tunnel.
Alternate Routes (And Why They’re Not as Bad as They Sound)
If you can’t use the tunnel, you’ll need to reroute — but it’s not terrible (mostly).
To Bryce Canyon National Park
Route: Highway 20 (north of Cedar City)
Distance: ~150 miles
Time: ~2.5 hours
Adds: 63 miles but only an extra 42 minutes (approx.) because you use faster roads (vs. Zion’s <30 MPH speeds).
To Grand Canyon North Rim
Route: Highway 59 toward Jacob Lake
Distance: ~128 miles
Time: just over 3 hours
Adds: 23 miles but only an extra 10 minutes (approx.)
To Mt Carmel / Zion’s East Rim
OK, this is pretty terrible and you definitely need to plan around this.
Route: Highway 59 toward Centennial Park, then 237 to Highway 89
Distance: ~82 miles
Time: 1 hour 40 minutes
Adds: 54 miles and doubles the time (adds approx. 50 minutes)
Other routes can be found using your preferred navigation app.
The biggest pain for me is not at the start or end of my trip – it’s if I want to visit the East Mesa during my trip. It means that if I have an RV or trailer, I need to plan around this, because you can’t drive through the park.
What’s NOT Allowed Inside the Zion – Mt Carmel Tunnel
⛔ Vehicles over 13’1” tall
⛔ Semi-trucks
⛔ Hazardous materials
⛔ Vehicles over 50,000 lbs
⛔ Single vehicles over 40 feet
⛔ Combined vehicles over 50 feet
⛔ Bicycles
⛔ Pedestrians
Safety Tips for the Zion – Mt Carmel Tunnel (Don’t Skip These)
This is one of the busiest areas in the park, with a history of accidents and close calls.
Slow down as you approach and watch for rangers, pedestrians, and traffic.
Do not stop in the tunnel. It can be tempting, because there are amazing views through the windows cut into the walls of the tunnels at intervals. However, you’ll need to wait until you exit the tunnel and if you’re headed from the east entrance to the south entrance, there are several pullouts along the road where you can safely stop and take photos.
Don’t turn around at entrances. The trailhead for the Canyon Overlook Trail is just outside the east entrance to the tunnel – there are parking lots on both sides of the road (a little apart from each other). Park in the parking lot on the side of the road you are already on.
Follow all ranger instructions, of course.
✨ PUTTING IT ALL TOGETHER ✨
Figuring out how to get around Zion National Park is a very important step in planning your trip, and I hope this guide is helping.
However, as I’m sure you’re very aware, this is just one thing of many to decide and do. The thing that most people ask me about is
how to put it all together into an itinerary that actually makes sense. They decide how to get to Zion, but still worry about how to minimize the crowds, what to do – and when – and how to coordinate it all.
To help
take away the overwhelm of planning a trip to Zion, I’ve created several super
detailed itineraries.
Without them, people often feel stressed about planning their trip. With them, they have the confidence of getting all the info they need in one spot. Plus,
there’s flexibility built in, so they can easily adapt them to their own interests and activity levels.
There are 1-, 2-, and 3-day options for Zion National Park: all with detailed hour-by-hour schedules, including alternatives for different activity and fitness levels, plus trail maps and descriptions, driving instructions, important information, essential tips, and
everything else you need to make the most of your time in Zion National Park.
The itineraries include adjustments for people with longer vehicles.
➡️ Check out the three Zion National Park itinerary options
Additional help with your Zion trip planning
Do you have any other tips for driving the Zion-Mt Carmel tunnel? I’d love to hear from you. Join my private Facebook group National Parks Collectors and comment and let me know.
If you found this this article helpful, Pin It to your National Parks and Zion National Park boards!
James Ian is a national park, camping and hiking expert.
He has dedicated his life to travel, visiting more than 80 countries, all 7 continents and most of the national parks in the United States. With over 35 years experience in the travel industry, James has worked on cruise ships, at resorts and hotels, and as a travel planner who’s helped hundreds of people plan successful trips to US national parks.
Based on his experience visiting our national parks multiple times, in-depth research and expertise as a travel planner, James has published detailed itineraries for many of the major national parks in the US. These itineraries, as well as in-depth park guides, and other resources will help you have your own incredible trip to US national parks without stress and hassle.
As a national park expert, James has contributed to many publications, including USA Today, Newsweek, Time Business News, Savoteur, Best Trip, and Wired.
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