On June 25, 1876, Custer's army came upon the Indian village, peacefully camping along the Little Bighorn, and elected to attack. Custer did not believe the information from his scouts as to the true size of the Indian position. Custer separated the army into several columns; he lead one, General Reno another and General Benteen a third. A fourth column stayed in the rear to protect the army's horses. Custer's column was completely and swiftly annihilated while Reno lost about a third of his column.
Reno ordered a retreat that became chaotic, and for the next day fought off the attacking Indians in a holding action from his entrenched positions. The Indians withdrew at noon on June 26th.
Reno was severely criticized for his actions in not coming to Custer's aid. While he was exonerated following an 1879 formal inquiry, Reno's career and legacy were seriously harmed.