Plans for the dam were completed by 1961 and the groundbreaking ceremony took place on August 18, 1962. In front of a crowd of 15,000 people, President John F. Kennedy and California Governor Pat Brown gave the signal to detonate the first explosive charges in the San Luis dam site. Work began the same month to reroute Pacheco Pass Highway (today's SR 152) around the future reservoir basin. The primary contract for the dam itself was awarded to Morrison-Knudsen, Utah Construction & Mining Co., and Brown & Root in 1963 for $85.9 million. Alfred M. Petrofsky held the role of chief engineer.