When the USAF was created as a separate service in 1947, Military Air Transport Service was established to support the new Department of Defense, with responsibility for its support falling to the Department of the Air Force. Redesignated Western Transport Air Force (WESTAF), the organization managed all MATS operations from the Mississippi River west to the east coast of Africa until MATS was replaced by the Military Airlift Command in 1966. When MATS became MAC, WESTAF was redesignated 22d AF, with headquarters at Travis AFB, CA.