On 12 August 1871 Mackenzie and Colonel Benjamin Grierson were asked by Indian Agent Lawrie Tatum to begin an expedition against the Kotsoteka and Quahadi Comanche bands, both of whom had refused to relocate to a reservation after the Warren Wagon Train Raid.

On the fourth night of the march, the expedition established a base camp at the junction of the Salt Fork of the Brazos and Duck Creek, near the site of present Spur, Texas.

The following day, Col. Mackenzie decided to leave his infantry to fortify the base camp, and set out for Blanco Canyon with his cavalry, hoping to catch the Comanche by surprise, and strike a blow at them in their heartland.

[3] Near midnight, Quanah Parker personally led a small Comanche force which stampeded through the cavalry camp, driving off about seventy horses and mules.

[1]: 213 [2] Mackenzie's main column and the Tonkawa scouts, hearing the gunfire, advanced and probably saved the detachment from slaughter, as more Comanche had managed to surround the retreating unit.

[1]: 177  The Comanches fought their way up the walls of Blanco Canyon, sniping at the oncoming troopers and taunting their Tonkawa enemies before disappearing from the Army's sight as they went over the Caprock Escarpment, and onto the Llano Estacado, Carter lacerating his leg against a boulder in the process.

However, he had marched to the heart of the Comancheria (and mapped the region in the process), penetrated an area of the Llano Estacado no Americans except Comancheros had ever seen, destroyed the winter equipment of the Comanche he encountered, and temporarily driven them from their homeland.