The last battle between two Indian tribes in Iowa was fought in 1854 on Avery Hill between the Winnebago and the Sioux. Some eighteen Sioux warriors, under the leadership of Coustawa (Big Tree), surprised the tribe of Winnebago but were driven back after the death of Coustawa. Once of the Sioux warriors was reported to be Inkpaduta who later led a band of Sioux in the famed Spirit Massacre. The Pocahontas County Historical Society has marked the battle spot on the Clarence Stearns farm with a flag pole. This area was to be unoccupied neutral ground based upon an unwritten law. However, Sioux tribes were constantly at war with the Winnebago. About 30 friendly Winnebagos were encamped on the Des Moines River, preparing furs for market at the trading post at Fort Dodge, a day’s journey. Based on an account written by Editor Wm. D. McEwen in The Pocahontas Times on May 18, 1876, the battle ensued when Sioux Chief Coustawa attacked, killing 10 Winneabagos while only four escaped unwounded. Coustawa was killed in the battle. The Sioux removed their warriors, but early settlers found seven graves in the area. One of the Sioux band was Inkpaduta, known for the Spirit Lake Massacre of 1857. A large boulder on the Three Rivers Recreation Trail has a plaque commemorating the site.