Pg.89 #3423 Interior view of Nevada Valve House, looking downstream. Note N-6 Emergency Gate being installed. Aug. 27, 1935. Pg.89 #3424 Nevada Valve House roof, looking upstream. Note low strength pedestals and double layer of railroad iron being placed. Aug. 27, 1935. Pg.89 #3407 Switchyard control house, yard and present sub-station. View taken looking toward Boulder Dam. Aug. 26, 1935.