# 31st Air Division

The 31st Air Division (31st AD) is an inactive United States Air Force organization. Its last assignment was with Air Defense Command, assigned to Tenth Air Force, being stationed at Sioux City Municipal Airport, Iowa. It was inactivated on 31 December 1969.

## History

Assigned to Air Defense Command (ADC) for most of its existence, the division equipped, administered, trained, and provided combat ready forces within an area covering North Dakota, South Dakota, Nebraska, Minnesota, and other parts of the Midwest. The division participated in numerous live and simulated exercises such as Creek Chief, Pawnee Knife, and Mandan Hunt.
Later, beginning in 1966, the 31st assumed responsibility for the former Oklahoma City Air Defense Sector and covered an area including Texas, Oklahoma, Arkansas, and Louisiana. Assumed additional designation of 31st NORAD Region after activation of the NORAD Combat Operations Center at the Cheyenne Mountain Complex, Colorado and reporting was transferred to NORAD from ADC at Ent Air Force Base in April 1966.
Inactivated in December 1969 as ADC phased down its interceptor mission as the chances of a Soviet bomber attack on the United States seemed remote, its mission being consolidated into North American Aerospace Defense Command (NORAD).

## Lineage

* Established as the 31st Air Division (Defense) on 7 September 1950
    Activated on 8 October 1950
    Inactivated on 1 February 1952
* Organized on 1 February 1952
    Inactivated on 1 January 1960
* Redesignated 31st Air Division and activated on 20 January 1966 (not organized)
    Organized on 1 April 1966
    Inactivated on 31 December 1969

### Assignments

* Air Defense Command
    Eastern Air Defense Force, 8 October 1950 (attached 30th Air Division, 27 November 1950 – 1 February 1951
    Central Air Defense Force, 20 May 1951 – 1 January 1960
* Air Defense Command, 20 January 1966 (not organized)
    Fourteenth Air Force, 1 April 1966 – 1 July 1968 (ConAC)
    Tenth Air Force, 1 July 1968 – 31 December 1969

### Stations

* Selfridge Air Force Base, Michigan, 8 October 1950 – 1 February 1952
* Fort Snelling (later Snelling Air Force Station), Minnesota, 1 February 1952 – 1 January 1960
* Oklahoma City Air Force Station, Oklahoma, 1 April 1966 – 31 December 1969

### Components
#### Sectors

* Duluth Air Defense Sector: 20 December 1957 – 1 January 1959
    Duluth Municipal Airport, Minnesota
* Grand Forks Air Defense Sector: 8 December 1957 – 1 January 1959
    Grand Forks Air Force Base, North Dakota

#### Groups

    53d Fighter Group: 18 August 1955 – 1 March 1956
    Sioux City Municipal Airport, Iowa
    343d Fighter Group: 18 August 1955 – 1 January 1959
    Duluth Municipal Airport, Minnesota
    475th Fighter Group: 18 August 1955 – 2 January 1958
    Minneapolis-Saint Paul Municipal Airport, Minnesota
* 478th Fighter Group: 8 February 1957 – 1 January 1959
    Grand Forks Air Force Base, North Dakota
* 514th Air Defense Group: 16 February 1953 – 18 August 1955
    Minneapolis-Saint Paul Municipal Airport, Minnesota
* 515th Air Defense Group: 16 February 1953 – 18 August 1955
    Duluth Municipal Airport, Minnesota
* 521st Air Defense Group: 16 February 1953 – 18 August 1955.
    Sioux City Municipal Airport, Iowa