Work on the dam started in 1961, with foundation drilling and survey work. Construction of the reservoir required the relocation of US 50 and State Highway 149. This relocation was among the first work to be performed, starting in 1962 and continuing through 1964. The Sapinero Cemetery was also relocated. The primary construction contract for the dam was awarded to the Tecon Corporation of Dallas, Texas, with notice to proceed on April 23, 1962. The diversion tunnel was holed through on September 7, 1962, with excavation of the spillway tunnel completed by the April 1963. Drilling and grouting for the dam's foundation started in March 1963. The Gunnison was diverted through its tunnel on October, with excavation of the foundation to bedrock immediately after. Placement of the dam embankments started in 1964, continuing through the year, with the dam embankment completed at the end of 1965. The diversion tunnel was partly closed in December and the reservoir began to fill, with final closure of the diversion tunnel on February 7, 1966. The dam project was declared complete on October 19, 1966.