Needles Eye Tunnel Sign in Custer State Park South Dakota

Needles Eye Tunnel carries the Needles Highway through a narrow granite passage in Custer State Park, South Dakota. The tunnel is just over 8 feet wide and roughly 12 feet high, dimensions that force larger vehicles like RVs and buses to find alternate routes. It takes its name from the nearby Needles, a cluster of slender granite spires shaped by millions of years of erosion. The road itself, completed in 1922, was championed by South Dakota Governor Peter Norbeck, who laid out much of its winding path on horseback to preserve the surrounding rock formations. Needles Highway remains one of the routes leading toward Mount Rushmore, connecting Custer State Park to the Black Hills beyond.