Lake Mineral Wells State Park and Trailway, a Texas state park in Mineral Wells, opened in 1981 and covers 3,282.5 acres around Lake Mineral Wells. It is the only Texas state park that protects part of the Western Cross Timbers along with the Mineral Wells Trailway. The park is known for Penitentiary Hollow, a small canyon-like formation popular for top-rope rock climbing, and for more than 31 miles of trails, with many open to bicycles and horses. The Trailway follows the former Weatherford, Mineral Wells and Northwestern Railway, opened in 1891 and abandoned in 1992, and part of the park crosses the former Fort Wolters Military Reservation testing range.