Aerial view of Hoover Dam and Lake Mead in Black Canyon, taken from the dam's downstream side. The intake towers and electric power transmission towers are seen. Typed label on back of photograph: "Down-stream face - Boulder Dam."
Interior of Diversion Tunnel No. 2 at Hoover Dam during construction on the ceiling. The tunnel is illuminated by electric lights. Typed label on back of photograph: "Nevada. Diversion Tunnel No. 2 on Nevada side. Putting in ceiling."