Place · 0.8 mi away
Overview
The Pigtail Bridges are the signature twists on Iron Mountain Road (SD 16A), where the highway makes a full loop and crosses over itself to quickly gain elevation. There are three of these wooden, steel-strapped spiral bridges, built to blend into the Black Hills forest and slow you down so you actually enjoy the scenery.
What Makes It Special
This isn’t just a drive; it’s a bit of road art. Across 17 miles you’ll encounter 314 curves, 14 switchbacks, three rock tunnels, and the three pigtails—tunnels even line up picture-perfect views of Mount Rushmore when you’re headed north. The pigtails are the playful heart of the route and a favorite of drivers, motorcyclists, and photographers.
What to Expect
- Very curvy, intentionally slow going—think 20–35 mph.
- Tight tunnels and narrow lanes; big rigs and trailers will not have fun here.
- Rustic timber-and-steel bridges and classic Black Hills scenery: pine forest and granite outcrops.
- No amenities at the bridges themselves—this is a drive-through experience.
History Snapshot
Conceived in the early 1930s by visionary Peter Norbeck and engineered by C.C. Gideon, Iron Mountain Road rejected the straight-and-fast approach. Gideon designed the wooden pigtail bridges and championed blasting the tunnels, giving the highway its distinctive rhythm and those Rushmore-framing moments.
Wildlife
Keep your eyes peeled along Iron Mountain Road for bison, antelope, deer, wild turkeys, and bighorn sheep. Every pass can feel different—drive attentively and be ready to stop.
Tips for the Drive
- Do it in both directions—the views change and the tunnels frame Rushmore best northbound.
- Take it slow and expect sudden stops as folks gawk at views.
- If you’re in an RV or towing, park it and use a smaller vehicle.
- The road can close in winter—check conditions before you go.
Best Time to Visit
Early morning or late afternoon offers prettier light, fewer cars, and cooler temps. Summer brings the most traffic (and potential backups); shoulder seasons are calmer. Aim for weekdays if you can.
Pros
- Ingenious wooden spiral bridges where the road loops over itself
- Part of a route with tunnels that frame Mount Rushmore
Cons
- Tight, winding curves and narrow tunnels challenge larger vehicles
- No on-site facilities and traffic can back up in peak season
- Curves can trigger motion sickness
Tips
- Drive it in both directions; northbound tunnels frame Mount Rushmore.
- Plan to go 20–35 mph and expect sudden stops at viewpoints.
- Leave RVs and trailers parked—use a smaller vehicle.
- Check for winter closures before you head out.
- Bring a camera; the pigtails and tunnels are the stars.
