Pg.48 #2847 Looking upstream at Boulder Dam and the Powerhouse, from the downstream Cofferdam. Sept. 27th, 1934. Pg.48 #2850 Nevada Powerhouse from the Arizona Valve House bench. Sept. 27th, 1934. Pg.48 #2853 Close-up of the Nevada Powerhouse, showing the draft tubes. Sept. 27th, 1934. Pg.48 #2851 Arizona Powerhouse from the Nevada Valve House bench. Sept. 27th, 1934.