29 August 1865, Ranchester, Wyoming: Launching the Powder River campaign, Brig. Gen. Patrick E. Connor led his Left Column north from Fort Laramie on 30 July. They moved up the Bozeman Trail to the Powder River, where the 6th Michigan Cavalry, who had accompanied the column to build a new post at the river, began constructing Fort Connor.
Connor continued north with his column on 22 August, trailing along the east edge of the Bighorn Mountains to the Tongue River and moving downstream toward the planned meeting place with other columns under Col. Nelson Cole and Col. Samuel Walker. On the 28th, scouts brought word of an Indian village 40 miles upstream at the head of the tongue. Connor prepared to backtrack and attack.
Leaving part of the command with the 184-wagon train, Connor led 125 cavalrymen and 90 scouts in a night march to Black Bear and David's Arapaho village, a mile south of present-day Ranchester, Wyoming. There were nearly 300 lodges with about 700 Indians. Though it was early in the morning, the Indians were dismantling the camp. Connor lined up his men, who fired a volley then barreled into them. The soldiers fought with the warriors while the women and children fled. A battery of howitzers under Maj. Nicholas O'Brien of the 7th Iowa Cavalry blasted the village.
Capt. Henry E. Palmer of the 11th Kansas Cavalry said of the fight: "I was in the village in the midst of a hand to hand fight with warriors and their squaws, for many of the female portion of this band did as brave fighting as their savage lords. Unfortunately for the women and children, our men had no time to direct their aim... squaws and children, as well as warriors, fell among the dead and wounded."
Connor led a pursuit up the valley for ten miles. At about 11 a.m., at the edge of a canyon, he turned around and found he had outdistanced most of his support and now had only about 13 men with him. He retreated to the Indians' village site and spent the rest of the day destroying the lodges and burning tons of buffalo robes, blankets, furs, and meat. The number of horses Connor captured was estimated between 500 and 1,100. In the late afternoon, Connor marched his men the 40 miles back to the wagon train. The soldiers had been in the saddle for 100 miles and without rest for 40 hours.
Connor lost 2 soldiers and 3 scouts, and 7 soldiers were wounded. He captured 7 women and 11 children, but later freed them. Connor estimated that 35 Indians were killed, while Palmer said 63 were slain.