A black and white image of Secretary of the Interior, Ray Lyman Wilbur driving the last spike into the railroad from Las Vegas to the site of the Hoover Dam, signaling the beginning of construction. Also in the photograph are the following: Congressman William Eaton, of Colorado; Senator Key Pittman, Nevada; and Senator Samuel Shortridge. The celebration took place either at Boulder Junction (south of Las Vegas) or in Boulder City.
From Union Pacific Railroad Collection (MS-00397). The scales are noted in the drawing. The bottom of the drawing says "Floor Plan". The corner of the drawing says, "Union Pacific System L.A. & S.L.R.R. Lavatory & Locker Room. Plans Elevations & Details. Caliente Nevada".