The Yakama Indian Reservation is a United States Indian reservation located on the east side of the Cascade Mountains in southern Washington. It is the homeland of the Yakama tribe of Native Americans.
According to the United States Census Bureau, the reservation covers 2,185.94 square miles (5,661.56 km²) and the population in 2000 was 31,799. It lies primarily in the Yakima and the northern edge of Klickitat counties, however, a tiny section crosses the southeast corner of Lewis County as well. The largest city on the reservation is Toppenish.
The reservation was created in 1855 by a treaty signed by Washington Territory Gov. Isaac Stevens and representatives of the Yakama tribe. A dispute over the treaty led to the Yakima War (1855–1858).