The Titan I ICBM program at Larson was initiated in 1959 when the Walla Walla District of the Army Corps of Engineers set up an area office in October. The contractor broke ground on 1 December 1959 and the sites were turned over to SAC in early April 1961. In May 1964 Secretary of Defense Robert McNamara directed that the phase-out of the Atlas and Titan I missiles be accelerated, and in January 1965 the missiles of the 568th were taken off operational alert. The squadron was inactivated 2 months later.