Canada as part of the Pinetree Line. These stations were turned over to the Royal Canadian Air Force in the early 1960s. In May 1960, SAGE Combat Center Number 3 (CC-03) became operational at McChord, bringing these separate Direction Centers under a unified center under the 25th AD. In July, DC-16 at Stead was reassigned to the 28th Air Division at Hamilton Air Force Base, California and the inactivation of the Western Air Defense Force brought the 25th AD directly under the control of Air Defense Command. In 1966 it was assigned to Headquarters, Fourth Air Force at Hamilton, although it remained stationed at McChord. It also replaced the Seattle Air Defense Sector in 1966. Assumed additional designations of 25th NORAD Region and 25th CONAD 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. Assumed additional designation 25th ADCOM Region on 8 December 1978. The division was a major part of Air Defense Command, and later Aerospace Defense Command (ADCOM) in 1968. In 1979 it was incorporated into Tactical Air Command with the inactivation of ADCOM as a major command. Under Air Defense Tactical Air Command. In 1985 most active-duty units of ADCOM were inactivated or reassigned to other missions, and the air defense mission came under Air Force Reserve and Air National Guard units under First Air Force. It continued its mission until 1990, when the 25 AD was inactivated, with its mission and components becoming part of the First Air Force Northwest Air Defense Sector. Lineage Established as the 25 Air Defense Division on 27 September 1948 Activated on 25 October 1948 Redesignated 25 Air Division (Defense) on 20 June 1949 Inactivated on 1 February 1952 Organized on 1 February 1952 Redesignated 25th Air Division (SAGE) on 1 March 1959 Redesignated 25th Air Division on 1 April 1966 Inactivated on 30 September 1990 Assignments Fourth Air Force, 25 October 1948 Air Defense Command, 1 April 1949 Fourth Air Force, 8 July 1949 (attached to Western Air Defense Force after 10 November 1949) Western Air Defense Force, 1 August 1950 Air Defense Command, 1 July 1960 Fourth Air Force, 1 April 1966 Tenth Air Force, 15 September 1969 Aerospace Defense Command, 1 December 1969 Air Defense Tactical Air Command, 1 October 1979 First Air Force, 6 December