In 1902 plans were advanced to dam the Sweetwater River at a narrow point known as Devil's Gate. A more ambitious plan was proposed in 1903 by the newly established Bureau of Reclamation to dam a site below the confluence of the Sweetwater and the North Platte. The dam's design was carried out by George Y. Wisner of the Reclamation Service, with consulting engineer Edgar T. Wheeler. Exploratory drilling was started in 1903, and a contract for a long diversion tunnel was let in 1905. Bidding for the dam construction contract was plagued with delays; the initial contractor withdrew, citing bidding errors. Eventually, the construction contract was awarded to the Geddis and Seerie Stone Company of Denver, for an initial sum of $482,000, later to rise to $626,523.52. Difficulties with the construction of an upstream cofferdam, created by the contractor's improper blasting of loose rock from the canyon walls, led to the first delays. Foundation work on the dam started in January 1906, with the foundation set only deep.