One of the best-kept secrets in the state, Threshing Machine Canyon, lies near the park. Located along the old Butterfield Overland Despatch trail (BOD), the canyon is the site of an 1850s Native American attack on a wagon train bearing a threshing machine, is located in the wildlife area. In this historic canyon, you will find carvings dating back to the mid-1800s. A stone marker for the BOD trail can be seen along the highway near the Cedar Bluff dam.