The Wyoming Air National Guard was first organized in a small hangar on the southwest side of Cheyenne Municipal Airport, Wyoming, as the Army Air Forces' highly decorated 402nd Fighter Squadron was deactivated Nov. 10, 1945, and reactivated as the 187th Fighter Squadron. The unit was allotted to the National Guard on Aug 10, 1946, under Maj. Robert E. Sedman. Flying P-51s, the Wyoming unit was activated April 1, 1951 for service during the Korean Conflict, with personnel assigned to Clovis Air Force Base, N.M., Germany, Okinawa, and South Korea. In Korea, 18 Wyoming pilots flew 1,500 combat missions. In 1956, the Wyoming Air National Guard became the 187th Fighter Interceptor Squadron. Two years later, during 1958, it received its first F-86L Sabre Jet aircraft and was redesignated as the 153rd Fighter Interceptor Group.
The most dramatic change came for the Wyoming unit in 1961 when it changed from a fighter unit to flying C-119 Flying Boxcar aircraft and airlifting medical patients, with the newly designated 187th Aeromedical Transport Squadron. On June 21, 1963, it received C-121 Super Constellation aircraft and expanded its military airlift role to worldwide mission capabilities. Entering the realm of South East Asia and Vietnam, the Wyoming Air National Guard flew its first mission into the Southeast Asia theater combat zone in late 1964, and continued to do so through the take over of South Vietnam by its enemies. During early 1966 the unit became the 153rd Military Airlift Group, under the Military Airlift Command.
In 1972, the Wyoming Air National Guard received its first turbo prop C-130 Hercules aircraft, which has proved to be one of the toughest and most versatile aircraft ever built, and which the unit continues to fly over 30 years later. In 1975, the Wyoming Air Guard was selected for the unique role of aerial fire fighting. Two Wyoming C-130s were equipped with Modular Airborne Fire Fighting Systems (MAFFS) and began water/fire retardant bombing of fires throughout the United States. Those fire fighting mission still continue through the present.