The Massacre Canyon Battle took place on August 5, 1873, in Hitchcock County, Nebraska. It was one of the last battles between the Pawnee and the Sioux and the last large-scale battle between Native American tribes in the area of the present-day United States of America. The battle occurred when a combined Oglala/Brulé Sioux war party of over 1000 warriors attacked a party of Pawnee on their summer buffalo hunt. According to Indian agent John W. Williamson, who accompanied the hunting party, "On the 2d day of July, 1873, the Indians, to the number of 700, left Genoa for the hunting grounds. Of this number 350 were men, the balance women and children."