Chief Engineer of Boulder Dam was Raymond F. Walter of the Reclamation Service. Born in Chicago, he was named Arthur Raymond Walter.  At age five, he migrated with his father, a printer, in a covered wagon to the Leadville, Colorado gold rush, then drifted from one boom town to the next.  As a boy he dropped the Arthur from his name, inserted a meaningless initial F.  He learned civil engineering at Colorado Agricultural College (1893), surveyed Cameron Pass over the Great Divide, and supervised irrigation work.  He entered the U. S. Reclamation Service in 1902, rose to be its chief engineer.  Bald and bespectacled, he was a genial, easy-going engineer, never too busy or hyper-efficient to stop and talk to friends or strangers. 
Time Magazine
July 21, 1930 According to Stevens, it was Walter who collected and opened the bids for the construction contract for Hoover Dam on the morning of March 4, 1931.  He had also been a key figure in the design of the dam.
Stevens,JE  Hoover DAM p45, U. Oklahoma Press, 1988