The Tule Lake National Monument in Northern California is the site of the Tule Lake Relocation Center, constructed in 1942 by the United States government to incarcerate Japanese Americans from the West Coast for the duration of the World War II. The Relocation Center housed nearly 120,000 people, more than two-thirds of whom were United States citizens. In total, 9,840 people were held there over the four years it was open.
California later designated this Tule Lake camp site as a California Historical Landmark and in 2006, it was named a National Historic Landmark. In addition to remains of the concentration camp, this unit includes Tulelake camp, also used during the war, as well as the rock formation known as the Peninsula/Castle Rock.