Buckhorn State Park is a 6,990-acre Wisconsin state park southeast of Necedah on a peninsula in Castle Rock Lake, where the Wisconsin and Yellow rivers meet. Created through Wisconsin Department of Natural Resources land purchases from 1974 to 2009, it was intended to return the area to a more natural state. Part of the park is protected as the Buckhorn Barrens within the Wisconsin State Natural Areas Program. The park is notable for its varied landscapes, including floodplain forest, prairie, savanna, and desert-like terrain, and it is valued both for recreation and for preserving diverse natural environments.