Walnut Creek State Park was an Oklahoma state park on the north shore of Lake Keystone, about four miles west of Prue. Established in 1966, it spanned 1,400 acres and operated year-round as a lakeside recreation area. The park offered shoreline access, camping, trail use, sandy beaches, a softball field, a picnic shelter with tables, RV hookups, tent sites, and restrooms. Its fifteen-mile Sand Plum Trail accommodated hikers, horseback riders, and mountain bikers, and an equestrian campground was also available, though horses were not rented there. Oklahoma permanently closed the park on October 1, 2014, and the U.S. Army Corps of Engineers was tasked with deciding the remaining facility’s final disposition.