Iron Mountain Road

Iron Mountain Road (US Highway 16A) was built in the 1930s by South Dakota Senator Peter Norbeck and spans 17 miles with 314 curves, 14 switchbacks, 3 wooden pigtail bridges, and 3 stone tunnels. The pigtail bridges are uniquely designed wooden loops that spiral back on themselves to gain elevation while preserving the landscape. Each of the three stone tunnels is deliberately aligned to frame Mount Rushmore's faces through the exit tunnel. The road climbs from the Custer State Park area east toward Mount Rushmore, blending seamlessly with the rugged landscape. A.B.A.T.E. rates this as difficulty Level 5. Allow 1 to 1.5 hours including photo stops at tunnels and pigtail bridges.