In March 1942, the Wartime Civilian Control Administration (WAA), under the direction of the Western Defense Command/ Fourth Army, requested the South Pacific Division of the United States Engineer Corps to construct suitable facilities at Manzanar to receive voluntary and forced Japanese American internees from the west coast of the United States. Using Army and Japanese American labor, approximately 825 buildings and structures were constructed. These included 445 barracks, 30 recreation halls, 32 mess halls, male and female latrines, and laundry facilities. Other improvements included an administration building, an auditorium, 37 warehouses, 8 observation towers, 2 sentry houses, police headquarters, and maintenance facilities. Hospital facilities and an orphanage were also provided. All of these facilities were constructed of wood, covered with tar paper, and situated on approximately 670 acres of the site. Other facilities on the remainder of the site included a 600,000 gallon reservoir, irrigation improvements, water and sewage treatment facilities, hog pens and chicken houses.
On 21 March 1942, the Wartime Civilian Control Administration organized the voluntary evacuation of approximately 2,100 Japanese Americans from Los Angeles, California, to the Manzanar site. The Commanding General of the Southern California Sector, Western Defense Command provided an escort for the convoy of cars and a collateral train movement. On 29 March 1942, the first compulsory evacuation of Japanese Americans from Bainbridge Island, Washington to Manzanar was executed. Eventually, 10,000 Japanese Americans were relocated to the site. When it became evident that all persons of Japanese ancestry would eventually be evacuated from the west coast, the government urged that a civilian agency supervise the post evacuation phases of relocation. Accordingly, on 18 March 1942, the War Relocation Authority (WRA) was established in the Office for Emergency Management of the Executive Office of the President and liaison was created between the WCCA and the WRA. On 17 April 1942, a formal agreement was executed in which the relocation centers would be acquired and constructed by the Army while the centers themselves would be administered by the WRA. Based on this agreement, the Manzanar Reception Center was formally transferred to the War Relocation Authority on 1 June 1942. In this transfer, the War Department retained its leasehold interest on the 5,964 acre site yet granted to the WRA a license, revocable on 30 days written notice, to occupy the site. In turn, the Army transferred the buildings, installations, fixtures and equipment to the WRA. The accountability for buildings, fixtures, installations and equipment provided by the U.S. Engineer District was transferred to the WRA in addition to all responsibility for administration, expense, and maintenance of the center.
The last internee left the Manzanar Relocation Center on 25 November 1945. On 2 January 1946, the Relocation Center site and its improvements were declared excess and assigned by the War Assets Administration to the Interior Department for disposal. In June 1946, the War Department terminated its lease with the City of Los Angeles. On 1 April 1947, the government transferred to the City of Los Angeles, those Manzanar fixtures not disposed of by the WAA.
The City of Los Angeles subsequently leased portions of the site for grazing purposes. The County of Inyo leased from the City of Los Angeles, and has continuously used the former camp auditorium as a garage and maintenance facility. The United States Congress established and set aside 550 acres of the encampment area, including the former auditorium, as a National Historic Site on 3 March 1992. This acreage is currently administered by the National Park Service under the Department of the Interior. Plans are currently being developed to perform restoration and interpretive activities on the site in order to provide enhanced visitor opportunities. The remainder of the site is still owned by the City of Los Angeles.
The auditorium is the only building that remains intact. All other buildings were either destroyed or moved and many of the structures are still being used throughout the Owens Valley. Structural remains are present at 490 of the 785 structures formerly on the site. The location of most of the other buildings can be defined based on topographic features, vegetation, or artifact concentrations. Internee constructed features which remain on site include ponds, pond/garden complexes, gardens with extensive rock work, and rock walls. Around the camp perimeter, the foundations of five of the original eight guard towers are still in place. The northern boundary of the camp is parallel with a graded road constructed after camp occupation. The foundation blocks for the three northern towers were pulled and are lying at various locations along this road.
The 600,000 gallon reservoir located to the northwest of the site, appears to be in good condition, and has been periodically used as a swimming area by local residents for many years. The sand traps, settling basins, flumes, and dams associated with this reservoir remain in good condition although portions have been overgrown with vegetation and covered with rocks and sediment.