The Hanford Reach National Monument is a national monument in the U.S. state of Washington. It was created in 2000, mostly from the former security buffer surrounding the Hanford Nuclear Reservation. The area has been untouched by development or agriculture since 1943. Because of that it is considered an involuntary park. Ancestors of the Wanapum People, Yakama Nation, Confederated Tribes of the Colville, Confederated Tribes of the Umatilla Reservation and the Nez Perce used the land for hunting and resource collecting.