Historical Research -
Air Force

History of the Air Force on Misawa’s Security Hill

On January 23, 2003 the 373rd Intelligence Group (IG) will celebrate 50 years of service at Misawa Air Base, Japan. The Security Service presence was born in Misawa when pioneers of the 1st Radio Squadron Mobile entered a remote section of Main Base via a narrow causeway between Lake Ogawara in January 1953. Despite numerous Unit designator changes and operations spanning four Intelligence Commands (USAFSS, ESC, AFIC, & AIA), the pulse of Misawa’s Security Hill beats on.

The Unit was first activated in February 1942 at Fort George Wright in Washington as the 138th Signal Radio Intelligence Company. The 138th transferred to Johnson Air Base in Iruagawa, Japan on 2 Sep 1945. In March 1944 while serving in the jungles of New Guinea during WWII, the 138th was re-designated the 1st Army Air Forces Radio Squadron Mobile. The order was later amended to read “1st Radio Squadron Mobile (1st RSM)”.

The 1st RSM was assigned to the United States Air Force in 1947 and transferred to Misawa Air Base, Japan in January 1953.

In May 1955, HQ USAFSS changed the 1st RSM to the 6921st Radio Squadron Mobile (RSM) and in July 1956 changed it again to the 6921st Radio Group Mobile (RGM). The 6921st RGM had two subordinate squadrons; the 6986th RSM at Wakkanai Air Station, Japan and the 6989th RSM also on Misawa Air Base. The 6921st RGM was then re-designated the 6921st Security Wing (Scty Wg) in September 1962.

During the early to mid 1960s Security Hill saw several large-scale changes. Construction of the huge circular FLR-9 antenna and the present-day operations building began in July 1963 and were completed in March 1965.

The 6921st Scty Wg was changed to the 6921st Security Group on 1 April 1970. The USAFSS assumed command responsibilities for the entire Misawa Air Base on 1 July 1972. This marked the activation of the 6920th Air Base Squadron. The Air Base Squadron began its mission of supporting the Base.

On 1 Sep 1972 the 6921st Security Group was changed back to the 6921st Scty Wg and the 6920th Air Base Squadron was re-designated the 6920th Air Base Group. Also, on 1 July 1974 the 6920th Security Group was activated and became the operational Unit of the Wing. Finally, on 1 Feb 1976 the 6921st Scty Wg was inactivated and replaced by the 6920th Security Wing.

The 6920th Security Wing, the 6920th Air Base Group, and the 6920th Security Group were retired on 29 Sep 1978. In their place, the 6112th Air Base Wing was activated as the base host Unit. The 6920th Security Group, in turn, was re-designated the 6920th Security Squadron and became a tenant Unit on base.

The 6920th Security Squadron was short-lived. On 1 Aug 1979 it took a step up the echelon ladder and was changed to the 6920th Electronic Security Group (ESG). The 6920th ESG remained until 1 Oct 1993 when it was re-designated the 301st Intelligence Squadron (IS).

Wing-level restructuring again brought the “Group” back to Misawa in Sep 2000, except under a different name. On 16 Sep, the 373rd IG was activated under the command of Colonel Dennis R. Mitzel. The 373rd IG has two subordinate squadrons; the 373rd Support Squadron and the 301st IS.


• 1st Radio Squadron Mobile (RSM). Moved to Misawa on 26 Jan 1953
• 6921st Radio Squadron Mobile (RSM). Activated on 8 May 1955 (1st RSM re-designated)
• 6921st Radio Group Mobile (RGM). Activated on 11 May 1956 (6921st RSM re-designated)
     – 6986th RSM on Wakkanai Air Station, Japan
     – 6989th RSM on Misawa’s Security Hill
• 6921st Security Wing (Scty Wg). Designation on 1 Sep 1962 (6921st RGM re-designated)
• 6921st Security Group. Designation on 1 Apr 1970 (6921st Scty Wg re-designated)
• 6920th Air Base Group. Activated on 1 Jul 1972 and assumed command of Misawa Air Base
• 6921st Security Wing (Scty Wg). Designation on 1 Sep 1972 (6921st Scty Group re-designated)
     – 6920th Security Group. Activated on 1 Jul 74 (operational unit of Wing; replaced 6989th RSM ????)
• 6920th Security Wing HQ. Designation on 1 Feb 1976 (6921st Scty Wg re-designated)
• 6920th Security Squadron. Designation on 1 Oct 1978 (6920th Security Group Inactivated)
• 6920th Electronic Security Group. Designation on 1 Aug 1979 (6920th Scty Sq re-designated)
• 301st Intelligence Squadron (IS). Designation on 1 Oct 1993 (6920th ESG re-designated)
• 373rd Intelligence Group (IG). Designation on 16 Sep 2000
   :  – 301st Intelligence Squadron
     – 373rd Intelligence Squadron (activated)

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