Ground Equipment Facility J-33

Ground Equipment Facility J-33 (Mill Valley Air Force Station until 1980)
Part of 1951-1968: Air Defense Command 1968-1979: Aerospace Defense Command 1979-1980: Air Defense, Tactical Air Command
Mount Tamalpais West Peak, 3.1 miles (5.0 km) WNW of Mill Valley
The FAA sign for the facility
Coordinates	37°55′26″N 122°35′49″W / 37.92389°N 122.59694°W / 37.92389; -122.59694 (Mill Valley AFS P-38)
Type	general surveillance radar station
Site information
Owner	Marin Municipal Water District
Site history
Built	1951
In use	1951-1980 (USAF) 1980-2005 (FAA)

Part of
1951-1968: Air Defense Command
1968-1979: Aerospace Defense Command

Ground Equipment Facility J-33 was a Federal Aviation Administration (FAA) radar station of the Joint Surveillance System's Western Air Defense Sector (WADS) with an Air Route Surveillance Radar (ARSR-4). The facility was previously a USAF general surveillance radar station during the Cold War.

Their sites are located on West Peak of Mount Tamalpais, in Marin County, California.

The Cold War radar station near Mill Valley was one of twenty-eight stations approved by the United States Secretary of Defense on July 21, 1950, as part of the Permanent System radar network (the Corps of Engineers managed construction for the USAF). Construction began at an upper location of the former World War II Mount Tamalpais Radar Site of the Aircraft Warning Service (the World War II information center of the AWC was located at tbd for plotting radar tracks in the San Francisco area).