Historic California Posts, Camps, Stations and Airfields
Los Angeles Back-Up Storage Facility
(Fontana Back-Up Storage Facility, Rialto Ammunition Back-Up Storage Point)

US Army Corps of Engineers Los Angeles District History (1993)
Beginning 31 December 1941, the War Department acquired 2821.75 acres from several different owners; 2814.105 acres through direct purchase or declaration of taking, 7.6 acres leased. The site was known as The Los Angeles Backup storage Facility. This name was later changed to Rialto Ammunition storage Point.
The site was developed for use as an ammunition depot. The Army constructed a complete weapons storage facility including igloo-type structures and many miles of railroad track. The Rialto Ammunition Storage Point remained active until late 1945.

On 13 November 1945, the Army reported 2814.15 acres fee and 7.60 acres leased as excess to the War Assets Administration. Custody was assumed by the Farm Credit Administration on 9 July 1946. This acreage was then subdivided over a number of years and sold. Much of the area is currently used for commercial activities, while portions in the north and east are single family residential homes.
US Army Corps of Engineers Los Angeles District History (1999)
Site Name: Rialto Ammunition Storage Point; also known as Los Angeles Backup Storage Facility, Ammunition Backup Storage, Fontana Backup Storage, Rialto Backup Storage, Ordnance Backup Storage Depot

Location: The Rialto Ammunition Storage Point is located in San Bernardino County approximately 5 miles north of the City of Rialto and 10 miles northeast of the City of Fontana, CA.

Site History: The 2,822.15 acre property was acquired in 1942 from several different land owners through direct purchase, declaration of taking or lease The Army's Ordnance Corps used the
property to store and mobilize ammunition and high explosives.

According to Army documents, no manufacturing of ordnance took place at the facility. Ordnance was stored in 20 concrete, reinforced bunkers and in railroad cars stored in earthen barricades. During the operation of the storage facility, approximately 2,000 acres were leased for crop cultivation and grazing. Military improvements to the property include the bunkers, various buildings located in the building area of the depot, bomb shelters, water well, sewage plant, and a total of seven underground storage tanks, but only the bunkers, one bomb shelter, and a water well have been beneficially used subsequent to military possession. Several of the tracts were already improved with small dwellings and farm buildings when acquired by the army. Some of these uildings were renovated and used by the Army in addition to the newly constructed military improvements. On November 13, 1945, all of the property was declared surplus and custody of the property was transferred to the Farm Credit Administration for disposal in July 1946. The property is now used for both industrial (including a municipal landfill owned and operated by the County of San Bernardino) and residential purposes.
US Army Center of Military History Status Card - Posts, Camps, Stations and Airfields
Link to Official Corps of Engineers Histories:
Final Report Operational History 1941-1945, Rialto Ammunition Back-Up Storage Point


Known Units at this Site

 3 June 1943 Army Station List

 7 April 1945 Army Station List

 7 May 1946 Army Station List
 622nd Ordnance Ammunition Company (AGF)  Detachment, 9205th Transportation Corps Technical Service Unit (ASF)  Surplus status, no units assigned.


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Updated 8 February 2016