Left to right shown are: Elwood Mead, Comm. Of Reclamation; Phil Swing, author of the bill, a member of House of Representatives from California; President Coolidge; U.S. senator Hiram Johnson, another author of the boulder Dam bill; Addison T. Smith, Chairman, Committee on Reclamation, House of Representatives; W.B. Matthews, General Counsel, Boulder Dam Association, Los Angeles, California. The occasion is the signing of the Boulder Dam bill, Dec. 21, 1928.

From the Elizabeth Harrington Photograph Collection (PH-00291). Inscription with image reads: "Driving the silver spike. Dr. Ray Lyman Wilbur, Secretary of the Interior, drives the last spike into tracks of railroads spur to the damsite. To the right of Dr. Wilbur is Senator Key Pittman. Nest to Pittman is Nevada Governor Fred Balzar. Second back from Senator Pittman is Las Vegas Mayor Fred Hesse. To the left of Dr. Wilbur is Carl R. Coray, Union Pacific Railroad president." - E(lizabeth) Harrington.