Inside The Needles Eye Tunnel, Custer State Park, South Dakota

The Needles Eye Tunnel carries the Needles Highway through a granite spire in Custer State Park, South Dakota. Carved in the 1920s under the direction of Governor Peter Norbeck, who helped design the route, the passage measures just over eight feet wide and roughly twelve feet tall, barely wide enough for a single vehicle. Norbeck laid out the highway's course on foot and by horseback before construction began in 1919, insisting the road bend around the granite formations rather than blast through them wherever possible. The tunnel takes its name from the thin, needle-like rock spire rising just beside it. Needles Highway itself runs about 14 miles and connects Sylvan Lake to the park's eastern entrance near Legion Lake.