The Confederated Tribes of the Umatilla Indian Reservation are the federally recognized confederations of three Sahaptin-speaking Native American tribes who traditionally inhabited the Columbia River Plateau region: the Cayuse, Umatilla, and Walla Walla. The reservation is also home to about 300 Native Americans enrolled with other Tribes, such as the Yakama, Tenino (Warm Springs), and Nez Percé. 1,500 people who are not Native American also reside within the reservation boundaries.