The Eye of the Needle, this unique rock formation, is nestled in the Black Hills of South Dakota along Needles Highway. The granite rocks, best known of all igneous rock, are scattered throughout this area. This needle's eye was formed by wind and water erosion and a mechanical process known as frost wedging.
The Black Hills are famous for carved faces at Mount Rushmore and the colossal sculpture of Crazy Horse. Custer State Park lies south of Needles Highway and is home to the largest buffalo herd. The Black Hills area can keep sightseers busy for days. Mount Rushmore, Crazy Horse, pigtail bridges on Iron Mountain Road, granite spires and needles, black pine forests, one lane tunnels, lake views and mountain vistas are many of the highlights of this area located just south of the hospitable town of Grand Rapids, South Dakota.