Historic California Posts, Camps,
Stations and Airfields
Birds Landing Very High Frequency
(VHF) Site 4K4
(Birds Landing Direction Finding
by Dan Sebby, Military Historian, California
VHF 4K4 Military Reservation was established
at Birds Landing in 1942 as a radio direction finding station;
it was part of a string of radar stations that ran along the
coastal regions of the Continental United States. The Site was
initially under the control of the 4th Antiaircraft Command's
San Francisco Fighter Control Area. The 411th Army Air Forces
Base Unit (AAFBU), headquartered at Berkeley, California, was
responsible for manning the Site.
A San Francisco District Engineer, USACE, correspondence dated
28 January 1944 indicated only two buildings were built at the
Site. One was a wood framed Theater of Operation type barracks.
It is not currently known what purpose the other building served,
but it could be surmised that it was a "Theater of Operations"
type building. Photographic evidence indicates that for defensive
purposes, the Site also had a concrete .50-caliber machine gun
positioned at the highest point of the Site, allowing a 360-degree
field of fire.
On 28 February 1947, as part of reorganization of the West Coast's
air defense radar systems, the 411th AAFBU was consolidated with
two other AAFBUs and became Squadron B, 412th AAFBU (Western
Aircraft Control & Warning Group). On 21 May 1947, the 412th
AAFBU was redesignated as the 505th Aircraft Control and Warning
Group with Squadron B becoming 636th Aircraft Control and Warning
Squadron. Concurrent with the reorganization, the Site was deactivated
and stripped of its equipment, which was shipped to the Berkeley
Early Warning Station.
On 28 July 1947, the Site was declared surplus to the needs of
the U.S. Army, and the lease was terminated on 1 January 1948.
Department Inventory of Owned, Sponsored and Leased Facilities,