Historic California Posts, Camps, Stations and Airfields
Laytonville Gap Filler Annex P-37A
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
Site Name: Laytonville Gap Filler Annex (Z 37A). The site was also known as Laytonville Gap Filler Annex (P 37A); Gap Filler Radar Site P 37A, Laytonville; and Laytonville GFA (P 37A), CA.
Location: The site is located in Mendocino County, five miles west of Laytonville, CA
Site History: On 24 February 1960 the U.S. Air Force acquired 8.72 license acres in addition to 6.09 public domain acres acquired by transfer from the Department of Interior for a total of 14.81 acres. The site was developed by the Air Defense Command Installation as an unmanned radar gap filler station. The site was an subinstallation of Point Arena Air Force Station and provided radar coverage to an area blocked from Point Arena's radar coverage by the mountainous terrain.
he improvements included one concrete block building, a chain link security fence, and a gravel surfaced road. On 30 August 1963, 6.09 public domain acres were re transferred to the Department of the Interior and on 1 November 1963, 8.72 license acres were terminated without restoration. The Bureau of Land Management of the Department of the Interior currently owns the site.

Real Estate Map


Source: Los Angeles District, US Army Corps of Engineers


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Updated 8 February 2016