Tenino Indians. A Shahaptian tribe formerly occupying the valley of Des Chutes River, Oregon. The Tenino dialect was spoken on both sides of the Columbia from The Dalles to the mouth of the Umatilla. In 1855 they joined in the Wasco treaty and were placed on Warm Springs Reservation, since which time they have usually been called Warm Springs Indians, a term embracing a number of tribes of other stocks which were included in the treaty. The present number of Tenino is unknown, but it is probably not more than 30.