From the Morgan Sweeney Photograph Collection (PH-00228). Hoover Dam. [Working on Hoover Dam] June 3, 1955. Stamp on verso: "P45-301-10534-A Official Photograph United States Department of the Interior Bureau of Reclamation If reproduced credit U.S. Bureau of Reclamation Photo by F. S. Finch JUN 3 1955."