 The older Titan I's were inactivated in March 1965.On 1 June 1971, SAC inactivated the 821st Strategic Aerospace Division and by October of that year, an upgraded LGM-30F Minuteman II also replaced the Minuteman I missiles.Ellsworth soon became known as one of "The Showplaces of SAC" along with Minot AFB and Grand Forks AFB in North Dakota as it continued to fight the Cold War by maintaining two legs of America's strategic triad