WW II Camp
Colorado River Relocation Center (April 1942 - March 1946), on Colorado Indian lands near Poston, 12 miles southwest of Parker in La Paz (formerly part of Yuma) County, that had a peak population of about 18,000.
Yuma County – Colorado River – Site of former Japanese detention camp (near proving grounds). This site was completely removed in 1990 according to some reports.
The U.S. Army's Yuma Proving Ground is one of the largest military installations in the world. Situated in southwestern La Paz County and western Yuma County in southwestern Arizona, U.S., approximately 30 miles (48 km) north-east of the city of Yuma, the proving ground is used for testing military equipment and encompasses 1,307.8 square miles (3,387.2 km²) in the Sonoran Desert. A resident population of 782 persons lived on its territory as of the 2000 census.