Looking up Black Canyon from a point below all the lower portals, showing the Government pumping plant (lower left), the Six Companies' compressor plant (middle left), the location of the lower portals, & the highway loop above the canyon wall (upper center) - 7/30/31.

p.1 #857 Steel suspension truck bridge immediately below lower portals of diversion tunnels. Lower Portals of Diversion tunnels No.3 and 4 in background. Feb.3, 1932 p.1 #911 View of warehouse and machine shop area. Boulder City in background. Feb. 15, 1932. p.1 #824 Lower steel suspension bridge under construction. Jan. 25, 1932.

p.15 #1075 Temporary cable-way spanning Colorado River, near Look Out Point, provide access to Arizona Spillway operations shown in background. Apr. 1, 1932. p.15 #1076 Skipload of workmen being transported across Colorado River from Arizona side. Apr. 1, 1932.

p.24 #1766 - p.24 #1767 Panoramic view of upper cofferdam, looking downstream. Nov. 26, 1932. p.24 #1744 Lower portals of Diversion Tunnels No.3 & 4, after diversion of Colorado river was completed. Nov. 14, 1932. p.24 #1778 Upper cofferdam, taken from Lookout Point. Nov. 29, 1932.

Pg.2 #2260 Nevada Spillway, looking upstream. June 27th, 1933. Pg.2 #2242 Lower Portals of Diversion Tunnels, discharging, 73,000 cubic feet per second flow into Colorado River. June 16th, 1933. Pg.2 #2259 Arizona Spillway, looking upstream, June 27th, 1933.

Pg.9 #2388 Boulder Dam, looking upstream. Oct. 15th, 1933. Pg.9 #2405 Upstream plug in Diversion Tunnel No. 3, after excavation of raise and Upstream Uptake Tower was completed. Oct. 30th, 1933. Pg.9 #2413 Boulder Dam, looking downstream. Oct. 31st, 1933.

Pg.18 #2528 Forms for transition at the Downstream Plug of Diversion Tunnel No. 2. Jan. 27th, 1934. Pg.18 #2507 Nevada Spillway Weir section. Jan. 24th, 1934. Pg.18 #2506 Nevada Spillway, looking upstream. Jan. 24th, 1934.