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 Air Force Station located on the summit of Mount Umunhum in the Santa Cruz Mountains, the station is a few miles south of San Jose, California and sits 3,486 feet (1,063 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.
The AN/FPS-24 radar became operational in 1962, and the AN/FPS-20
was removed soon afterward and its concrete foundation was re-purposed as a helipad.
The original GATR building on the summit of Mount Umunhum was subsequently converted to supply storage and ultimately used as a training room facility.
Operations ceased on 1 April 1980 as a result of budget restrictions, and the general phase down of air defense radar stations.