"# 623 View looking upstream from point near the
Government water intake on the Nevada side. The lower portals of Diversion Tunnels Nos. 2, 3 and 4 are shown. The bridge in the foreground, in addition to being a footbridge, carries a six-inch compressed air-pipe, gasoline pipe and water pipe. November 29th, 1931.
§ 622 Jack-hammer men drilling open cut excavation to lower portal of Diversion Tunnel No. 1. Note the hard-boiled hats, which are used by Six Companies Inc. employees, and which all men working in the canyon are required to wear. November 29th, 1931.
# 589 Drilling the first round in enlarging upper
portal of Diversion Tunnel No. 2. The welded steel ""Jumbo"" mounted on the truck has twenty-five air-drills on it. The Swing Shift crew is waiting to go to work. November 18th, 1931.
# 590 Looking downstream toward the damsite, from a
point near the upper portals of Diversion Tunnel No. 2. November 18th, 1931."