Drilling jumbos (aka Williams Jumbo) mounted on the back of a truck for starting construction of lower portal No. 4, Arizona side of Black Canyon. 9-26-31. (This first wood-frame jumbo was experimental - the jumbos later were steel pipe)

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.

Pg.43 #2789 Boulder Dam, looking upstream from Lookout Point. July 31st, 1934. Pg.43 #2777 Looking downstream at Boulder Dam, from the Arizona side. July 24th, 1934.

Pg.44 #2776 Close-up of No. 3 Arizona Intake Tower, showing the cylinder gates being placed. July 24th, 1934. Pg.44 #2775 Close-up of the Arizona Intake Towers, from the High Catwalk. July 24th, 1934.

Pg.25 #2578 Boulder Dam, looking upstream. March 16th, 1934. Pg.25 #2618 Boulder Dam, looking upstream. April 1st, 1934.

Pg.1 #2262 Hoover Dam. June 27, 1933. Pg.1 #2256 Cut-off trench at upstream side of Hoover Dam. June 23rd, 1933. Pg.1 #2263 Hoover Dam. June 27th, 1933.

Pg.28 #2590 Arizona Intake Towers, from the Nevada Himix trestle, with Arizona Spillway shown in the background. March 24th, 1934. Pg.28 #2591 Nevada Intake Towers from the Arizona side. March 24th, 1934.