Photographs taken by Major Lee Moorhouse between approximately 1897 and 1919, depicting Cayuse, Umatilla, and other Native peoples and their settlements in the Columbia River Basin and Umatilla County; landscapes in Oregon and Montana; the Pendleton Round-Up in Pendleton, Oregon, and rodeos in other locations.

Collection consists of a black-and white, silent home movie of the Pendleton Round-Up that was taken in September 1927. Footage includes rodeo events, bulls, a parade of horses, and Native participants. The Round-Up, held in Pendleton, Oregon, since 1910, features events including barrel racing, calf roping, and steer wrestling, as well as a parade and a night show.