Almaden Air Force Station
Encyclopedia
Almaden Air Force Station is a closed United States Air Force
General Surveillance Radar station. It is located 6.1 miles (9.8 km) southeast of Los Gatos, California
. It was closed in 1980.
(Um-un-um) in the Santa Cruz Mountains
, the station is a few miles south of San Jose
, California
and sits 3486 feet (1,062.5 m) above Almaden Valley. Great difficulties were encountered in construction at this site. During fiscal year
1957, the Air Defense Command held up construction due to funding shortfalls.
This site became operational on 1 September 1957 when the 682nd Aircraft Control and Warning Squadron was assigned to the new station by the 28th Air Division. The station was equipped with AN/FPS-20 and twin AN/FPS-6 radars which went operational in March, 1958. In 1961 the site received an AN/FPS-24 radar, but could test the radar only on a not-to-interfere basis with television transmissions. This radar became operational in 1962, and the AN/FPS-20 was removed soon afterward. In 1963 an AN/FPS-90 replaced the second AN/FPS-6 height-finder and the original AN/FPS-6 was removed and replaced with an AN/MPS-14 height finder adjacent to the AN/FPS-24 radar tower.
During 1961 Almaden AFS joined the Semi Automatic Ground Environment
(SAGE) system, feeding data to DC-18 at Beale AFB, California. After joining, the squadron was re-designated as the "682d Radar Squadron (SAGE)". In 1963, the SAGE site was switched to DC-17 at Norton AFB, California. Also on 31 July 1963, the site was re-designated as NORAD ID Z-96. In 1979 Almaden AFS came under Tactical Air Command
(TAC) jurisdiction with the inactivation of Aerospace Defense Command and the creation of ADTAC. Operations ceased on 1 April 1980 as a result of budget restrictions, and the general phase down of air defense radar stations.
The station operated a Ground-to-Air Transmitter-Receiver (GATR) atop the summit of Mount Umunhum
up until the completion of the AN/FPS-24 radar in 1962. To eliminate radio frequency interference from the AN/FPS-24 radar, the GATR was then moved one mile east to the summit of Mount Thayer
. The original GATR building was subsequently converted to supply storage and ultimately as a training room facility.
The station today is abandoned and off-limits to the general public. It was acquired in 1986 by the MROSD (Midpeninsula Regional Open Space District
). The site is now a part of the Sierra Azul Open Space Preserve
although it is not yet open to the public because of environmental hazards (asbestos
, black mold, and lead
-based paint). The MROSD estimates it will take at least US$13.1 million to clean up the base for public use.
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
General Surveillance Radar station. It is located 6.1 miles (9.8 km) southeast of Los Gatos, California
Los Gatos, California
The Town of Los Gatos is an incorporated town in Santa Clara County, California, United States. The population was 29,413 at the 2010 census. It is located in the San Francisco Bay Area at the southwest corner of San Jose in the foothills of the Santa Cruz Mountains...
. It was closed in 1980.
History
Almaden Air Force Station was established in 1954 by Air Defense Command as one of a planned deployment of forty-four Mobile radar stations to support the permanent ADC Radar network in the United States sited around the perimeter of the country. This deployment was projected to be operational by mid-1952. Funding, constant site changes, construction, and equipment delivery delayed deployment. Almaden AFS was located on the summit of Mount UmunhumMount Umunhum
Mount Umunhum is the fourth-highest peak in the Santa Cruz Mountains of California . The mountain is situated in Santa Clara County, southeast of Los Gatos and south of South San Jose...
(Um-un-um) in the Santa Cruz Mountains
Santa Cruz Mountains
The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central California, United States. They form a ridge along the San Francisco Peninsula, south of San Francisco, separating the Pacific Ocean from San Francisco Bay and the Santa Clara Valley, and continuing south,...
, the station is a few miles south of San Jose
San Jose, California
San Jose is the third-largest city in California, the tenth-largest in the U.S., and the county seat of Santa Clara County which is located at the southern end of San Francisco Bay...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and sits 3486 feet (1,062.5 m) above Almaden Valley. Great difficulties were encountered in construction at this site. During fiscal year
1957, the Air Defense Command held up construction due to funding shortfalls.
This site became operational on 1 September 1957 when the 682nd Aircraft Control and Warning Squadron was assigned to the new station by the 28th Air Division. The station was equipped with AN/FPS-20 and twin AN/FPS-6 radars which went operational in March, 1958. In 1961 the site received an AN/FPS-24 radar, but could test the radar only on a not-to-interfere basis with television transmissions. This radar became operational in 1962, and the AN/FPS-20 was removed soon afterward. In 1963 an AN/FPS-90 replaced the second AN/FPS-6 height-finder and the original AN/FPS-6 was removed and replaced with an AN/MPS-14 height finder adjacent to the AN/FPS-24 radar tower.
During 1961 Almaden AFS joined the Semi Automatic Ground Environment
Semi Automatic Ground Environment
The Semi-Automatic Ground Environment was an automated control system for tracking and intercepting enemy bomber aircraft used by NORAD from the late 1950s into the 1980s...
(SAGE) system, feeding data to DC-18 at Beale AFB, California. After joining, the squadron was re-designated as the "682d Radar Squadron (SAGE)". In 1963, the SAGE site was switched to DC-17 at Norton AFB, California. Also on 31 July 1963, the site was re-designated as NORAD ID Z-96. In 1979 Almaden AFS came under Tactical Air Command
Tactical Air Command
Tactical Air Command is an inactive United States Air Force organization. It was a Major Command of the United States Air Force, established on 21 March 1946 being headquartered at Langley Air Force Base, Virginia...
(TAC) jurisdiction with the inactivation of Aerospace Defense Command and the creation of ADTAC. Operations ceased on 1 April 1980 as a result of budget restrictions, and the general phase down of air defense radar stations.
The station operated a Ground-to-Air Transmitter-Receiver (GATR) atop the summit of Mount Umunhum
Mount Umunhum
Mount Umunhum is the fourth-highest peak in the Santa Cruz Mountains of California . The mountain is situated in Santa Clara County, southeast of Los Gatos and south of South San Jose...
up until the completion of the AN/FPS-24 radar in 1962. To eliminate radio frequency interference from the AN/FPS-24 radar, the GATR was then moved one mile east to the summit of Mount Thayer
Mount Thayer
Mount Thayer is a mountain in the Santa Cruz Mountains located in Santa Clara County, California. The summit is in a section of the abandoned Almaden Air Force Station, about 1 mile west of Mount Umunhum. The elevation of the summit is at feet. An old derelict building, surrounded by telephone...
. The original GATR building was subsequently converted to supply storage and ultimately as a training room facility.
The station today is abandoned and off-limits to the general public. It was acquired in 1986 by the MROSD (Midpeninsula Regional Open Space District
Midpeninsula Regional Open Space District
The Midpeninsula Regional Open Space District is a special-purpose district that manages over of open space in 25 preserves in the San Francisco Bay Area. It includes parts of Santa Clara, San Mateo and Santa Cruz Counties. The District was created by voter initiative in 1972...
). The site is now a part of the Sierra Azul Open Space Preserve
Sierra Azul Open Space Preserve
Sierra Azul Open Space Preserve is managed by the Midpeninsula Regional Open Space District in Santa Clara County, California. It's approximately in area. The park features the Sierra Azul range's peaks of Mount Umunhum, Mount Thayer, and El Sombroso...
although it is not yet open to the public because of environmental hazards (asbestos
Asbestos
Asbestos is a set of six naturally occurring silicate minerals used commercially for their desirable physical properties. They all have in common their eponymous, asbestiform habit: long, thin fibrous crystals...
, black mold, and lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
-based paint). The MROSD estimates it will take at least US$13.1 million to clean up the base for public use.
Units
- 682d Aircraft Control and Warning Squadron (moved to Almaden AFS, 1 September 1957)
- Activated at Geiger Field, Washington on 1 December 1953 (not manned or equipped)
- Moved to Kirtland AFB, New Mexico on 1 January 1954 (not manned or equipped)
- Moved to Hamilton AFB, California on 13 July 1954 (not manned or equipped)
- Redesignated 682d Radar Squadron (SAGE) on 15 January 1961
- Redesignated 682d Radar Squadron on 1 February 1974
- Inactivated on 1 April 1980
Assignments
- 28th Air Division, 1 September 1957
- San Francisco Air Defense SectorSan Francisco Air Defense SectorThe San Francisco Air Defense Sector is an inactive United States Air Force organization. Its last assignment was with the 28th Air Division, being stationed at Beale Air Force Base, California.- History :...
, 1 July 1960 - Los Angeles Air Defense Sector, 1 August 1963
- 26th Air Division, 1 April 1966
- 27th Air Division, 15 September 1969
- 26th Air Division, 19 November 1969 - 1 April 1980