The following is from the book, Encyclopedia of Indian Wars, by Gregory F. Micho.
The command marched to old Fort Reno on the Powder, where Mackenzie split off with the cavalry. On 25 November, scouts guided him to a large Cheyenne camp in a canyon on the Red Fork of the Powder, west of present-day Kaycee, Wyoming. There were 200 lodges under Dull Knife and Little Wolf, with 400 warriors. Mackenzie's 1,100 horsemen burst upon the village, driving the surprised Indians out onto the frozen ridges. A deadly fire ensued. The fight was hand-to-hand at times, the defenders knowing that if they lost their homes and supplies at the onset of winter, they would perish.
When the Cheyennes seemed about to recapture their pony herd, mackenzie sent Lt. John A. McKinney with Company A, 4th Cavalry, to stop them. Caught in a high-walled ravine and ambushed, McKinney went down with six bullets in him. Capt. John M. Hamilton's company of 5th Cavalrymen helped extricate the company. Finally, the soldiers secured the village, though the Cheyennes continued to pour in harassing fire from the rocks above.
During the fight, the Cheyennes suffered 40 killed and perhaps another 40 wounded. Mackenzie's casualties were 6 men killed and 26 wounded. The soldiers took more than 600 horses and burned all the lodges, leaving the Cheyennes to face the long winter without food and shelter. The night after the battle, the temperature dropped to 30 below zero, and 11 babies froze to death.