Iron Mountain Road is a section of 16A that goes from Custer State Park to Mount Rushmore National Memorial passing through Black Hills National Forest. This was a morning drive so there were a lot of deer and wild turkeys out roaming about. The road is famous for its framed tunnel views of Mount Rushmore. Here are some numbers about the road: 314 curves, 14 switchbacks, 3 pigtail turns, 3 tunnels and 2 road splits. Enjoy the drive.