Malmstrom SAGE Direction Center DC-20

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Malmstrom SAGE Direction Center DC-20 (1959-1983) - A Cold War SAGE System Direction Center first established in 1959 on Malmstrom Air Force Base, Great Falls, Cascade County, Montana. Named Malmstrom SAGE Direction Center after the location. Assigned a Sage ID of DC-20. Deactivated as a SAGE Direction Center in 1983.

Malmstrom SAGE Direction Center DC-20 Repurposed.


Established in 1959 and became operational on 15 Feb 1960 as Malmstrom SAGE Direction Center DC-20.

SAGE System Data Flow

Direction center equipment included the duplex FSQ-7 computer system and associated communication equipment. The FSQ-7 computer system assembled digitized inputs from USAF Radar Sites to provide tracking and identification of all aircraft within their sector of responsibility. The digitized radar inputs came from USAF Radar Sites, airborne radar pickets, Texas Towers, Gap Filler Radar Sites and other radar sources. The total picture of aircraft in the sector was assembled and any unknown aircraft were checked out and hostile aircraft were engaged by USAF fighter aircraft, Bomarc missiles or NIKE missiles. The primary defense was against the Soviet threat of a mass nuclear bomber attack on the US. The system evolved before the advent of ICBMs and provided no missile defense against them.

The computer technology was first generation vacuum tube equipment and required significant power and air conditioning. The physical plant of the direction center was enclosed in a large multi-story concrete blockhouse that housed the duplex FSQ-7 computer, communications equipment, a powerhouse, air conditioning systems and operational areas. The operational areas included radar mapping, air surveillance, identification, communications and weapons direction.

The enormous cost of the radar sites, direction centers, personnel, and training caused an immediate reevaluation and almost as quickly as they were built some facilities were closed. The first mass closures began in the 1960s when many radar sites and virtually all the gap filler sites were closed. The first round of direction center closures came in 1963 when six were closed, a second round in 1966 and a third in 1969 that closed a total of 17 out of 23. The remaining six direction centers became SAGE Regional Control Centers (RCCs) still using the massive FSQ-7 vacuum tube computers. As the direction centers and radar sites closed the remaining sites were realigned into ever-increasing sectors.

A new Joint Surveillance System (JSS) evolved as a partnership between the Air Force and the FAA to provide nationwide radar coverage. When completed in 1983 it consisted of only forty-six radar sites feeding into four new Region Operation Control Centers (ROCCs) with FYQ-93 computer systems. With the activation of the four U.S. ROCCs and the two Canadian ROCCs, the last seven of the SAGE direction centers were deactivated and this signaled the end of the SAGE system. Of the remaining forty-six radar sites, thirty-one had FAA-operated search radars and USAF operated height finders. Five sites just had FAA search radars and only ten sites were operated by the Military. With the deployment of forty FAA ARSR-4 3D radar sets in the 1990s, the earlier military and FAA radars were replaced.

The Canadians closed their underground SAGE Direction Center and created two ROCCs (CAN-East and CAN-West) using the FYQ-93 computers in the underground facility.

The Malmstrom SAGE Direction Center was one of the six direction centers designated as a SAGE Regional Control Centers (RCCs) in 1966 and it remained operational , still using the vacuum tube FSQ-7 computer, until 1 Mar 1983.

Malmstrom SAGE Direction Center DC-20 Assignments
Unit Designation Command From To Notes
Great Falls Air Defense Sector (GFADS) ADC 15 Feb 1959 1 Apr 1966
28th Air Division ADC 1 Apr 1966 19 Nov 1969 Sectors changed to Air Divisions in 1966
24th Air Division ADC 19 Nov 1969 1 Oct 1979 ADC Transitioned to TAC in 1979
24th Air Division TAC 1 Oct 1979 1 Mar 1983 SAGE Deactivated in 1983

Malmstrom SAGE Direction Center DC-20 Radar Sites (edit list)
Location Type State Unit ADC NORAD JSS From To GPS Notes
Cut Bank AFS MT 681st P-24 Z-24 1960-07-01 1965-06-25 48.94222,
Lewistown AFS MT 694th TM-178 Z-178 1960-07-01 1971-06-30 47.21754,
Dickinson AFS ND 706th TM-177 Z-177 1963-06-25 1965-06-25 46.92056,
Kalispell AFS MT 716th TM-179 Z-179 J-78 1960-07-01 1978-04-01 48.01139,
Havre AFS MT 778th P-25 Z-25 1960-07-01 1979-09-29 48.88083,
Opheim AFS MT 779th P-26 Z-26 1963-06-25 1979-09-29 48.86111,
Fortuna AFS ND 780th P-27 Z-27 1963-06-25 1979-09-29 48.90389,
Minot AFB ND 786th P-28 Z-28 1963-06-25 1979-09-29 48.00361,
Malmstrom AFB MT 801st SM-147 Z-147 J-77 1960-07-01 1969-12-31 47.50193,
Miles City AFS MT 902nd M-98 Z-98 1963-06-25 1968-06-18 46.29694,
Finley AFS ND 785th P-29 Z-029
J-75 1969-09-15 1979-12-30 47.51583,
Kamloops AS BC 825th SM-153 C-153 1982 1983-03-01 50.80222,
Beausejour AS MB 916th
C-17 C-17 R-25 1969-11-14 1983-05 50.14806,

Current Status

Sage Direction Center blockhouse repurposed on Malmstrom AFB in Great Falls, Cascade County, Montana.

Location: Malmstrom AFB, Great Falls,
Cascade County, Montana.

Maps & Images

Lat: 47.51639 Long: -111.18194

  • Multi Maps from ACME
  • Maps from Bing
  • Maps from Google
  • Elevation: 3,472'

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
  • 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


Fortification ID:

  • MT0130 - Malmstrom SAGE Direction Center DC-20

Visited: 12 Aug 2016

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