Mountain Home was the location chosen for an Air Force Base. Construction began in October 1942 and the base was officially opened 7 Aug 1943. It was initially called Army Air Base, Mountain Home. On 2 Dec 1943 it was redesignated as Mountain Home Army Air Base.
The first unit assigned was the 396th Bombardment Group (Heavy). Their mission was to train crews for the B-17 Flying Fortresses. However, before the B-17s arrived, the 396th was transferred to Moses Army Air Field, Washington.
Instead of training B-17 crews, Mountain Home airmen began training crews for the B-24 Liberator. The first group to do so was the 470th Bombardment Group (Heavy), which trained at Mountain Home from May 1943 until January 1944, when the unit moved to Tonopah Army Air Field, Nevada. The 490th Bombardment Group (Heavy) replaced the 470th and trained B-24 crews until it deployed to Royal Air Force Eye England in April 1944. The 494th Bombardment Group then replaced the 490th, once more training Liberator crews.
The base also received fighter aircraft to add realism to its training. A few P-38 Lightning and P-63 Kingcobra pursuit planes arrived in January 1945 to simulate attacks on B-24s. In June 1945, Mountain Home also briefly served as a training base for the new B-29 Superfortress with the 301st Bombardment Group (Very Heavy) training for combat, but the Japanese surrender in August brought a swift end to the new mission.
The base was de-activated 5 Oct 1945 and remained inactive until 13 Jan 1948.
The base remained inactive until December 1948 when the newly independent United States Air Force and its Strategic Air Command (SAC) assigned first the 5th Reconnaissance Group and then the 5th Strategic Reconnaissance Wing and their camera-equipped RB-17 Flying Fortresses to the newly renamed Mountain Home Air Force Base. This new lease on life was short-lived, however, lasting only until April 1950, when the base once again closed.
On 1 Feb 1951, the base was reactivated by the Military Air Transport Service, hosting the 580th, 581st, and 582nd Air Resupply and Communications Wings over the next three years. They flew C-119 Flying Boxcar, B-29 Superfortress, and SA-16 Albatross aircraft and trained to support covert special operations. When the last of these Air Transport wings departed for overseas duty in 1953, the base was transferred to the Strategic Air Command, which assigned its 9th Bombardment Wing to Mountain Home. The 9th relocated to Mountain Home AFB in May 1953, and began flying B-29 Superfortress bombers and KB-29H refueling aircraft. The 9th converted to the new B-47 Stratojet bomber and the KC-97 Stratotanker air refueling aircraft in September 1954, and kept alert bombers ready for war at a moment's notice and continued its mission as a SAC deterrent force through the early Cold War years of the 1950s and early 1960s.
In 1959, construction of three Titan I missile sites began in the local area. The 569th Strategic Missile Squadron controlled these sites and was assigned to the 9th Bombardment Wing in August 1962. To prepare for the addition of missiles to its bomber forces, Air Force re-designated the wing as the 9th Strategic Aerospace Wing in April 1962.
Two years later, SAC's mission at Mountain Home Air Force Base began to wind down, and in November 1964, the Air Force announced that the missile sites would be closed. In late 1965, the Air Force also phased out the aging B-47 bomber and announced plans to bring the 67th Tactical Reconnaissance Wing to Mountain Home.
In January 1966, with the closure of the missile sites and the move of the 67th to Mountain Home, control of the base passed from SAC to Tactical Air Command (TAC). The wing conducted photographic, visual, radar, and thermal reconnaissance operations. While having these operational commitments, it also conducted replacement training for RF-4C Phantom II crew members being deployed to Southeast Asia. In September 1966, the wing's 12th Tactical Reconnaissance Squadron transferred to the 460th Tactical Reconnaissance Wing at Tan Son Nhut Air Base, South Vietnam. As required, the 67th also supported operations when crew members ferried RF-4Cs to the war theater. Beginning in 1968, the 67th also conducted tactical fighter operations with the addition of a squadron of F-4D Phantom IIs. This fighter mission lasted until late 1970 when the F-4Ds were reassigned. When U.S. forces began the drawdown from South Vietnam, the 67th designation moved in July 1971 to Bergstrom Air Force Base, Texas. It was replaced by the 347th Tactical Fighter Wing, equipped with F-111F Aardvarks. The 347th had a short stay at Mountain Home, conducting F-111F training until October 1972, when the 366th moved from Vietnam to Mountain Home. Upon its arrival, the 366th absorbed all the personnel and equipment of the 347th.
The 366th Fighter Wing has remained at Mountain Home since its return from Vietnam. They are nicknamed the "Gunfighters".