Historic California Posts, Camps, Stations and Airfields
Oroville Army Air Field
(Oroville Gap Filler Annex)
In 1936, the City of Oroville acquired 188 acres of grazing land for use as a municipal airport. During 1941, the city and the Works Project Administration (WPA) extended the runways and increased the total airport land area to 428 acres.

In 1942, the War Department leased the Oroville Municipal Airport and renamed it Oroville Army Air Field (AAF). That same year the Army purchased an additional 381.98 acres of land for expansion of the field and construction of a cantonement area. Once operational, it served as a fighter group training installation from spring of 1943 through early summer 1944. Two fighter groups rotated through Oroville AAF: the 357th Fighter Group (fighter group of famed pilots Chuck Yeager and Bud Anderson) and the 369th Fighter Group. Aircraft present at the field were identified as the Bell P-39Q Airacobra, North American P-51B/C/D Mustangs, and possibly the North American A-36 Apache, the ground attack version of the P-51.
Layout plans of the former Oroville AAF dated 1944 indicate a Bomb Storage Area west of the two runways and a skeet range between the southern extents of the runways. Fueling pit boxes were located along former Taxiways A (running parallel to runway 12/30) and C (connecting the southernmost ends of runways 1/19 and 12/30). A 1947 Inventory Report of Buildings and Structures states that bombs were stored in earth revetments.

In 1945 Oroville AAF was listed as “temporarily inactive” under assignment to Air Technical Service Command and was later classified as surplus. In 1946 the War Assets Administration (WAA) assumed custody of the site and on 21 May 1947, the WAA terminated the U.S. Army’s lease with the City of Oroville and quitclaimed the fee owned property to that municipality.
Oroville Army Air Field in 1943 (National Archives)
Extract US Army Air Forces Directory of Airfields.
Oroville Gap Filler Annex
Typical AN/FPS-14 Gap Filler Radar
"During the late 1950s another area of progress was the development and deployment of AN/FPS-14 and AN/FPS-18 gap-filler radars. Having a range of around sixty-five miles, these radars were placed in areas where it was thought enemy aircraft could fly low to avoid detection by the longer-range radars of the permanent and mobile radar networks. Gap-filler radar deployment peaked in December 1960 at 131 sites throughout the continental United States. Because the introduction of gap-filler radars alleviated the need for civilians to scan the skies for enemy bombers, the ADC disestablished the Ground Observer Corps on January 31, 1959."
Searching The Skies
USAF Air Combat Command
June, 1997
Typical floorplan of a Gap Filler Annex
The 0.25-acre site is located at the Oroville Municipal Airport, approximately 4 miles southwest of the City of Oroville in Butte County, CA. On 14 October 1955, the Air Force acquired 0.25 fee acre from the City of Oroville with the intent of installing an unmanned gap filler station. No improvements were ever made to the site by the Air Force and on 6 January 1965 the parcel was conveyed back to the City of Oroville.


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Updated 8 February 2016