Mill Valley Early Warning Mission
The task of the 666th Squadron of the United States Air Force was to monitor the radar systems which tracked air movement in the area of Northern California. There was a real threat of Soviet nuclear attack on America's densely populated cities and the importance of their daily task should not be under estimated.
The Mill Valley station as part of this nationwide LASHUP system of early detection had a 200 mile visibility radius. Though the MVAFS and its sister stations were small, the Radar Squadrons played an important part in the national security system, especially the early warning systems. The Mill Valley Air Force Station was directly linked to the Nike missile sites in the area. One such site was located at Fort Barry (SF-88), now also part of GGNRA (Golden Gate National Recreation Area). This was an Army administered site and Mill Valley Air Force Station had an Army Air Defense Command Post.
According to Ever Watchful, the 666th Radar Squadron overview publication of 1975, the mission of the squadron was threefold. They were to provide reliable radar surveillance data to the 26th Air Division Direction Center. A second task at hand for the 666th was to provide target information to fighter aircraft under level V autonomous operation. Finally, the squadron was to maintain the equipment and facilities of the station at their optimum level of performance.
The 666th Radar Squadron was under the manual control system of operations from 1951 and was designated as a Master Direction Center. It had operational tactical control over three other Ground Radar Squadrons, two Navy picket ships, two Air Early Warning and Control Aircraft, sixteen Army Air Defense Artillery Nike-Ajax and Nike-Hercules units in the San Francisco-Travis Air Force Base complex.
In January 1961, the 666th Radar Squadron was integrated as a component of Semi-Automatic Ground Environment (SAGE). Their purpose was to feed initial target location data to the SAGE computer. At this time, the MVAFS was the headquarters for the San Francisco North American Defense (NORAD) Control Center, composed of both Army and Air Force personnel and equipment.
The following September, the squadron became host to the 40th Artillery Brigade Air Defense Command Post. The station was then equipped with Battery Integration and Radar Display Equipment (BIRDIE). They were also put in charge of the Nike-Hercules missile systems in the San Francisco-Travis AFB area. The target information which was gathered at MVAFS was processed and sent to the Nike-Hercules units. The 40th Artillery Brigade later became part of the 13th Artillery Group, Army Air Defense Command Post (AADCP).
By April of 1967, the 14th Missile Warning Squadron, Detachment 3 was also present at the MVAFS. At that time, installation of the AN/FSS-7 Sea Launched Ballistic Missile (SLBM) radar system took place.
In July of 1971, the 40th Artillery Brigade Air Defense Command Post was replaced by the 13th Artillery Group. In March of 1974, with the phase out of the Nike-Ajax and Nike-Hercules in the area, the 13th Artillery Group Air Defense Command Post was deactivated.
By 1975, the responsibilities of the 666th Squadron at MVAFS had been greatly reduced. However, the squadron was still responsible for supplying reliable radar surveillance data to the Air Defense System.
Initially known to residents of the area as a "weather station," the base was the topic of a local newspaper article in December of 1953. The article described the tasks of those airmen who watched the radar screens. In the first minutes after an airman detected a suspicious aircraft he attempted to identify that aircraft. If after several minutes the aircraft remained unidentified then the Mill Valley airman contacted Hamilton AFB near Novato, California, north of San Francisco. United States Air Force jets were then "scrambled" by radio. As these aircraft took off, they made contact with MVAFS radar center and the airman stationed in front of the radar screen guided the Air Force aircraft to the location of the suspicious intruder. Approximately ten of these scrambles occurred each day costing tax payers $1,000 per scramble.
Isolated on the top of Mount Tamalpais, the airmen had numerous activity centers at their disposal. They worked eight hour shifts, six-days a week, and spent most of their free time in comfortable barracks watching television, reporting the best reception in the county. The base was furnished with a swimming pool, a bowling alley, tennis courts, and a theater for the airmen to occupy their free time.
With increasing advances in technology such as the completion in 1957 of the Distant Early Warning System (DEW line) in Canada and then subsequent advances in satellite tracking and the early warning radar stations soon became obsolete. Another blow to the radar stations' usefulness was the development of the nuclear launch capability from offshore submarines. By the early 1980's most of the stations, including the Mill Valley site, were closed or re-designed to meet other needs. The Mill Valley Station was closed in January of 1983. Such rapid advances in technology however, increases the significance of the remaining early warning radar systems. Documenting generations of technological advances made by the military is currently a much discussed topic.
MVAFS itself was one of the most important radar stations in the country: at every phase of its history- as a control station in the 1950's, as a SAGE combat division center from 1961 to 1963, as San Francisco Defense Area NORAD Control Center from 1961 to 1974, and as one of six SLBM radar stations from 1968 to 1980- it was one of the few radar stations to hold a position of leadership.
The chain of command for the 666th Radar Squadron changed several times during its more than 30-year stay at MVAFS. Each change was associated with a modification of the station's mission. From 1949 to February 1952, the squadron was part of the 542nd AC & Warning Group with the command at Hamilton, AFB. The following changes in command occurred after that point:
November 1950 23rd Air Division
January 1952 - July 1960 28th Air Division Hamilton, AFB
July 1960 - August 1963 San Francisco ADS Beale, AFB
August 1963 - April 1966 Portland ADS Adair, AFB
April 1966 - Sept. 1969 26th Air Division Adair, AFB
Sept. 1969 - Nov. 1969 27th Air Division Luke, AFB
Nov. 1969 - March 1981 26th Air Division Luke, AFB