Illustration of the construction of Boulder Dam, later called Hoover Dam. Caption reads: "Boulder Dam and lower portals of diversion tunnels. Colorado River."
Hand-painted postcard showing an upstream view of Boulder (Hoover) Dam. Text on front of postcard: "Boulder Dam at Night"; Text on back of postcard: "Boulder Dam is the highest in the world, rises 727 feet above bed rock. It is 650 feet thick at the base, and the 45 foot crest forms a highway bridge from wall to wall of the gorge, 1180 feet in length, connecting transcontinental traffic arteries between Kingman, Arizona and Boulder City, Nevada. The view of the Dam at night is a most impressive spectacle."