Owyhee Dam A project of the Bureau of Reclamation, they hired General Construction Company from Seattle to build the dam. Former Oregonian and then United States President Herbert Hoover dedicated what was the highest dam of its type in the world on July 17, 1932. Secretary of the Interior Ray Lyman Wilbur delivered Hoover's message at the dam. Owyhee's construction served as a prototype for the larger Hoover Dam on the Colorado River, including the use of refrigeration to cool the concrete. The dam cost $6,000,000, with the total reclamation project costing $18,000,000. Owyhee was designed by Frank A. Banks, who also
Gibraltar Dam was the longest water tunnel in the world. The city sought to build a dam somewhere on the Santa Ynez River in order to increase the water supply available for Mission Tunnel. Between 1913 and 1919, revenue bonds totaling $820,000 were issued for the construction of the dam and water system. Several dam sites were considered including the Mono Creek, Juncal and Main River sites, but all were dropped in favor of Gibraltar, which offered the largest storage capacity and highest available run-off as well as the most geologically favorable dam site. Rock-fill, masonry and concrete designs were all studied.