Iron Mountain Road
Pigtails, tunnels, and granite cathedrals
Iron Mountain Road snakes through 17 miles of engineering marvel between Hill City and Mount Rushmore, featuring three pigtail bridges that spiral around themselves and four single-lane tunnels blasted through solid granite. The road was designed in the 1930s to frame Mount Rushmore perfectly through tunnel openings, creating some of the most photographed highway views in America. You’ll climb over 1,200 feet through dense ponderosa pine forests, granite outcroppings, and past the famous Needles formations that inspired the route’s dramatic engineering.
This is a moderate scenic drive suitable for any vehicle with decent brakes and patient nerves. The tunnels are narrow—RVs over 8 feet wide or 11 feet tall won’t make it through. Best driven May through October when snow doesn’t block the higher elevations. No permits required, but expect heavy tourist traffic in summer months. Fuel up in Hill City or Keystone. The payoff is some of the most spectacular mountain driving in the Midwest, with granite cathedrals rising on both sides and views that’ll make you forget you’re in South Dakota.
Trail Specs
| Difficulty | Moderate |
|---|---|
| Trail Type | Scenic Drive |
| Surface | Paved |
| Features | Historic, Scenic |
| Length (miles) | 17 mi / 27.4 km |
| Duration | Half day |
| Max elevation (ft) | 5445 ft |
| Best season | May-October |
| Minimum vehicle | Any vehicle (size restrictions) |
| Nearest town | Hill City, SD |
| Land manager | South Dakota Department of Transportation |
| Permit required | No |
| Cell service | Decent |
| Water crossings | No |
| Dispersed camping | No |
| Start coordinates | |
| End coordinates | |
| Copy both for Google Maps directionsClick to copy the directions URL · or open it directly in a new tab | |
| Find on Google | Search on Google → |
Location
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Frequently asked questions
Can a large RV or truck with trailer make it through the tunnels?
No. The tunnels have strict size restrictions - 12'3" wide and 12'6" high. Oversized vehicles must take alternate routes around the Black Hills.
Is Iron Mountain Road open year-round?
The road typically closes November through April due to snow and ice. South Dakota DOT maintains it May through October when conditions allow.
Do I need a permit or have to pay fees to drive Iron Mountain Road?
No permits or fees required. It's a public state highway, though you'll need park passes if you enter Custer State Park at either end.
How scary are the pigtail bridges and one-lane tunnels?
The pigtails are tight corkscrews with 15 mph speed limits but well-engineered. Tunnels are narrow but short - just take your time and watch for oncoming traffic at tunnel entrances.
Are there places to stop and take photos along the route?
Yes, multiple pullouts and scenic overlooks throughout the 17 miles. The tunnel framings of Mount Rushmore are the most popular photo spots, but arrive early to avoid crowds.