Mica Peak Air Force Station

From FortWiki
Jump to: navigation, search

Mica Peak Air Force Station (1958-1979) - A Cold War Air Force Radar Station first established in 1958 near Spokane, Spokane County, Washington. Named Mica Peak Air Force Station after the location. Initially assigned a Permanent ID of SM-151 and later a Sage ID of Z-151 and then a JSS ID of J-79. Transferred by the Air Force in 1979 to the FAA. Operated by the FAA as Mica Peak FAA Radar Site to the present.

Mica Peak FAA Radar Site from a Distance. (2016)


Established in 1958 and became operational in 1958 as Mica Peak Air Force Station manned by the 823rd AC&W Squadron. The station initially had both a Ground-Control Intercept (GCI) and an early warning mission. The early warning mission involved tracking and identifying all aircraft entering their airspace while the GCI mission involved guiding Air Force interceptors to any identified enemy aircraft. Controllers at the station vectored fighter aircraft at the correct course and speed to intercept enemy aircraft using voice commands via ground-to-air radio.

Initial equipment included the FPS-20 search radar and an MPS-14 height-finder radar. An FPS-6A Height finder was added in 1959 and the site became a joint-use site with the FAA.

SAGE System Transition

The transition of the manual GCI system to the automated SAGE system began with the installation of the FST-2 coordinate data transmitter and search radar upgrades. The FST-2 equipment digitized the radar returns and transmitted the digital returns to the SAGE direction center. Under the SAGE System, interceptor aircraft were directed to their targets by the direction center computers and controllers, greatly reducing the need for local controllers and equipment at every radar station.

The FST-2 was a very large digital system using vacuum tube technology. Over 6900 vacuum tubes were used in each FST-2 requiring 21 air-conditioned cabinets, 40 tons of air conditioning, 43.5 kva of prime power, and usually a large new addition to the operations building. The FST-2B modification added two more cabinets but with newer solid-state (transistor) technology to process coded responses from aircraft transponders.

SAGE System Operations

The site began operation as a SAGE site in 1960 initially feeding the Larson SAGE Direction Center DC-15. The search radar was upgraded to an FPS-67 in 1962 and an FPS-6 was upgraded to an FPS-90 in 1963. In 1963 the Larson SAGE Direction Center DC-15 was closed and Mica Peak AFS began feeding the McChord SAGE Direction Center DC-12. The FST-2 was replaced in the early 1970s with a FYQ-47 Common Digitizer located at the upper site.

Gap Fillers

Mica Peak AFS was responsible for the maintenance of four remote unattended gap-filler radar sites. The gap-filler sites were placed in locations where the main search radar lacked coverage. These sites sent digitized radar target data directly to a direction center. Maintenance teams were dispatched from Mica Peak AFS for regularly scheduled maintenance or when fault indicators suggested the site had problems.

Mica Peak AFS Gap Filler Radar Sites (edit list)
ADC NORAD Location State Type From To GPS Notes
SM-151C Z-151C Porthill ID FPS-14, FST-1 1958 1960 48.99333,
SM-151D Z-151D Moyie Springs ID FPS-18, FST-1 1960 1960 48.76333,
SM-151E Z-151E Yaak MT FPS-??, FST-1 19?? 19?? 48.86222,
Former Yaak AFS
SM-151F Z-151F Eureka MT FPS-14, FST-1 1958 1960 48.86474,


The 823rd Radar Squadron (SAGE) was deactivated on 1 Jul 1975.

Mica Peak FAA Radar Site

After the Air Force Station was deactivated the site on Mica Peak continued to operate as a Joint USAF/FAA JSS site by detachment (Det 2, TAC) and as operating location (OLA, 25th AD). After the FAA assumed maintenance responsibility in 1979 the Air Force continued height-finder operations until the height-finder radars were removed.

A FYQ-47 Common Digitizer was probably placed in service by February 1973 when the USAF/FAA FST-2 to FYQ-47 replacement program was completed. By 1990 the site was equipped with an FPS-67B search radar and a CD-2A Common Digitizer. The Mica Peak CD-2A was scheduled to receive an upgrade kit to implement three-level weather data processing in May 1992.

The FPS-67B search radar was updated with a 3D ARSR-4 radar during the 1996-1999 time frame. The ARSR-4 contains common digitizer functionality so the CR-2A was no longer required.

The radar site data is now available to the USAF/NORAD Battle Control System-Fixed (BCS-F) operations centers (EADS & WADS) as well as the FAA Seattle ARTCC (ZSE) and adjacent ARTCCs. Other federal agencies have access to the data under the Homeland Security umbrella.

Physical Plant

The physical plant of the site was divided into the main site and a radio site on Mica Peak. Geiger Field below housed an operations area, a cantonment, and a housing area. The main site on Mica Peak had an operations building, radar towers, and backup generators. The operations building was originally located on the lower site while the Army NIKE AADCP was operational. The Geiger Field operations area also housed the FST-2. A TELCO microwave system was used to transmit the radar data from the upper site to the FST-2 at Geiger Field. In May 1972 operations moved to the Mica Peak site. A separate radio site on the peak housed the radio equipment for directing aircraft intercepts. The lower cantonment area housed the enlisted barracks, the bachelor officer's quarters, the orderly room, the dining hall, and the motor pool. Apart from the cantonment area was a small housing area for married personnel. The housing area was closed and support was provided from nearby Fairchild Air Force Base sometime after Geiger Field became Spokane International Airport.

Mica Peak AFS Major Equipment List
Search Radar HF Radar Data Systems IFF/SIF/Beacon
Unit Designations
  • 823rd Aircraft Control & Warning (AC&W) Squadron (1955-1960)
  • 823rd Radar Squadron (SAGE) (1960-1975)
823rd Assignments

Current Status

Mica Peak Roadblock.

Operating as a joint-use FAA radar site with a 3D ARSR-4 radar set on Mica Peak. Motorized traffic to the site is prevented by a locked gate on the Mica Peak Radar Site Road near the intersection with South Star Road.

Location: On Mica Peak near the city of Spokane
in Spokane County, Washington.

Maps & Images

Lat: 47.57406 Long: -117.08126

  • Multi Maps from ACME
  • Maps from Bing
  • Maps from Google
  • Elevation: 5,194'

GPS Locations:

See Also:


  • Winkler, David F., Searching the Skies: the Legacy of the United States Cold War Defense Radar Program, USAF Hq Air Combat Command, 1997, 192 pages, Pdf, page 166.
  • Cornett, Lloyd H. & Johnson, Mildred W., A Handbook of Aerospace Defense Organization (1946-1980), Office of History ADC, Peterson AFB, Colorado, 31 Dec 1980, 179 pages, Pdf, page 171.
  • USGS Geographic Names Information System (GNIS) Database Entry: 2089510


Fortification ID:

  • WA0212 - Mica Peak Air Force Station
  • WA0213 - Mica Peak FAA Radar Site

Visited: Area 21 Aug 2016

Personal tools