By September only 500 Kiowa and Comanche were still on the reservation; the others were out on the Staked Plains. That same month the army began to move. Three converging columns moved into the heart of the Staked Plains. Trapped between them, the Comanches, Kiowa, and Cheyenne had little rest. Colonel Nelson A. Miles' column made the first contact and defeated a group of Cheyenne near McClellan Creek. For the Comanches, Cheyenne, and Kiowa, the major blow occurred when Mackenzie located a mixed camp hidden in Palo Duro Canyon (September 26–27). After driving off the warriors during a short battle on September 28, he burned the camp and killed 2,000 captured horses.