The Gila River War Relocation Center was an American concentration camp in Arizona, one of several built by the War Relocation Authority during the Second World War for the incarceration of Japanese Americans from the West Coast. It was located within the Gila River Indian Reservation near the town of Sacaton, about 30 mi southeast of Phoenix. With a peak population of 13,348, it became the fourth-largest city in the state, operating from May 1942 to November 16, 1945.