Just prior to World War II, the Civil Aeronautics Administration (CAA) selected the site as an important civil air field and negotiated a standard agreement (AP 4) with the county of San Bernardino to maintain the air field. Shortly thereafter, the site was chosen by the War Department as a Modification Center. As a result, the County acquired fee interest to the additional land necessary for War Department use. On 4 May 1942, the government entered into an agreement with the County to lease the 1,099 acre site (renewable annually but not beyond 30 June 1967).
On or about 29 May 1942, the government and Douglas Aircraft Company, Inc., entered into a cost plus fixed fee ($1.00) contract (No. W-509-ENG-2557), whereby Douglas agreed to do all things necessary and incident to the procurement, furnishing, delivery and installation of equipment, machinery, machine tools, materials, supplies and facilities for proper operation of a Modification Center. Douglas established the Modification Center and operated it until the middle of 1944, when Army Air Forces deactivated the project. According to a narrative report contained in project files, there was no evidence of the lease ever having been executed, so it was believed that Douglas occupied and used the premises without any written agreement.
On 12 November 1942, the Secretary of War and Standard Oil Co. (San Francisco) entered into an agreement (unnumbered lease to run with lease W-868-ENG-4504), whereby Standard Oil agreed to install, operate, and maintain lubricating oil storage and distribution facilities at the site. In addition, on 20 December 1943, the CAA was granted a permit (to run with Lease No. W-868-ENG-4505) to use and occupy two parcels of land totaling 11.2 acres at the Modification Center for a radio range and communication building site, together with a right of way between the two parcels for establishing and maintaining subsurface cable lines. The original permit period ended 30 June 1944, however, the lease contained a provision for annual renewal, at the option of the government, through 30 June 1967. Upon the expiration of the permit, all CAA property was to have been removed to a condition satisfactory to the Commanding Officer or other competent military authority.
Approximately 65 buildings and 20 other assorted structures were constructed at the facility (headquarters and flight operations buildings, hangars, barracks, sewage treatment plants, warehouses, water wells, water and fuel storage tanks, gasoline station, etc.). The total cost of government improvements was $3,924,273, with the CAA expending an additional $107,235 for various improvements. Douglas constructed a swimming pool, paint and dope storage shed, and an air hose station for which reimbursement was not made. According to airport personnel, improvements constructed by the County (non DOD) consisted of one building, and the addition of a small surface water pond in the vicinity.
The site (all 1,099 acres) was classified as surplus on 15 November 1945. According to the completed Declaration of Surplus Real Property Form (SPB 5, dated 28 March 1946), the improvements at the site were in good condition. Custody and accountability for the site was assumed by the War Assets Administration on 27 June 1946, with the installation immediately transferred to the Navy Department. According to airport personnel interviewed during the site visit, the County obtained control of facility from the military in 1958. Unfortunately, a fire during the 1960s destroyed County records of the transaction. During the period 1946 through 1958, it is not clear which agency and jurisdiction over the facility. From 1958 through the present, the airport was controlled by the current owner, the County. According to Exhibit A of the original 1942 lease with the County, the government, at its option, may leave in place the alterations and improvements made to the landing areas in lieu of restoration.
Army Corps of Engineers Archives Search Report