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. When the leaders of the Walla Walla, Cayuse, and Umatilla peoples signed the Treaty of Walla Walla with the United States in 1855, they ceded of their homeland that is now northeastern Oregon and southeastern Washington. This was done in exchange for a reservation of and the promise of annuities in the form of goods and supplies. The tribes share the Reservation, which consists of in Umatilla County, in northeast Oregon state. The tribes have created a joint political structure as part of their confederation. The tribal offices are just east of Pendleton, Oregon. Almost half of the reservation land is owned by non-Native Americans; the reservation includes significant portions of the Umatilla River watershed. In 2013 the three-tribe confederation populated about 2,916 people, roughly half of the tribal population live on or near the reservation. 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. History After ceding their territories, the Umatilla, Walla Walla, and Cayuse relocated to what was called the Confederated Tribes of the Umatilla American Indian Reservation (CTUIR). In exchange for ceding most of their territories they received supplies and annuities from the federal government, who then tried to encourage them to take up subsistence farming. Many times the supplies were late in coming or were inadequate for the population. In 1887, under the Allotment Act, communal land was distributed to households. This and other legislation made it possible for the members to sell their lands but they were preyed on by speculators and swindlers. Gradually the tribe took back communal control of its land and has regained more than of what was lost. In addition, in the 20th century tribe pursued a major land claim case against the federal government, saying that the three tribes had traditionally controlled one million more acres of land than they had been compensated for following the 1855 treaty. The Indian Claims Commission awarded the confederated tribes several million dollars in a negotiated settlement. They used some of that money in economic development efforts. They also paid per capita claims