The Cayuse are a Native American tribe in what is now the state of Oregon in the United States. The Cayuse tribe shares a reservation and government in northeastern Oregon with the Umatilla and the Walla Walla tribes as part of the Confederated Tribes of the Umatilla Indian Reservation. The reservation is located near Pendleton, Oregon, at the base of the Blue Mountains. The Cayuse called themselves the Liksiyu in the Cayuse language. Originally located in present-day northeastern Oregon and southeastern Washington, they lived adjacent to territory occupied by the Nez Perce and had close associations with them. Like the Plains tribes, the Cayuse placed a high premium on warfare and were skilled horsemen. They developed the Cayuse pony. The Cayuse ceded most of their traditional territory to the United States in 1855 by treaty and moved to the Umatilla Reservation, where they have formed a confederated tribe. History According to Haruo Aoki (1998), the Cayuse called themselves Liksiyu in their language. Their name Cayuse was derived from the French word "cailloux," meaning stones or rocks, adopted by early French Canadian trappers of the area. The name may have referred to the rocky area the tribe inhabited or it may have been an imprecise rendering of the name they called themselves. The tribe has been closely associated with the neighboring Nez Percé and Walla Walla. The Cayuse language is an isolate, independent of the neighboring Sahaptin-speaking peoples. The Cayuse population was about 500 in the eighteenth century. The Cayuse were a seminomadic tribe and maintained summer and winter villages on the Snake, Tucannon, Walla Walla, and Touchet rivers in Washington, and along the Umatilla, Grand Ronde, Burnt, Powder, John Day River, and from the Blue Mountains to the Deschutes River in Oregon. Historian Verne Ray has identified seventy-six traditional Cayuse Village sites, most temporary, seasonal sites; five separate villages in the Walla Walla Valley and seven Cayuse Bands scattered throughout Eastern Oregon and Washington. The Walla Walla River Cayuse Band was called the Pa'cxapu. Other sources name only three distinct regional bands within the Cayuse at the time; two centered on the Umatilla River; the third on the Walla Walla River. The Cayuse were known for their bravery and as horsemen. They bred their ponies for speed and endurance, developing what is now called the Cayuse horse. No longer restricted to what they could carry or what their dogs could