Archival objects in this container: Box of equipment being lowered into Black Canyon for Hoover Dam construction, approximately 1930-1935 Box of equipment being lowered into Black Canyon for Hoover Dam construction, 1933 May 22 Box of equipment being lowered into Black Canyon for Hoover Dam construction, approximately 1930-1935 Worker riding on a cable hook to the bottom of the canyon during Hoover Dam construction, approximately 1930-1935 Debris-filled canyon during Hoover Dam construction, 1933 June 27 Hoover Dam construction site, 1934 April 17 Cement plant area at the Hoover Dam construction site, 1933 April 01 Cement plant water tanks and railroad freight cars at the Hoover Dam construction site, 1934 April 17 Cement plant water tanks during Hoover Dam's construction, 1934 March 01 Cement plant works for transporting gravel and water at the Hoover Dam construction site, approximately 1930-1935 Black Canyon floor at the Hoover Dam construction site, approximately 1930-1935 Head tower hoist house and permanent 150-ton cableway at the Hoover Dam construction site, approximately 1930-1935 Head tower hoist house and permanent 150-ton cableway at the Hoover Dam construction site, approximately 1930-1935 Hoover Dam's base forms, 1933 September 14 Base forms at Hoover Dam, approximately 1931-1934 Top forms at 710 foot elevation at the Hoover Dam construction site, 1933 November 27 Showing the construction and pouring of dam forms at the Hoover Dam construction site, 1933 December 27