"1388 The period of danger from high water having passed, protecting arch coffer dams are blasted from the lower portals of the diversion tunnels, and muck fill is being removed. July 27th, 1932.
1418 Trucks with 4 cubic-yard concrete agitators crossing the upstream steel suspension bridge, from the Arizona side. Upper portals of Diversion Tunnels No. 3 and No. 4 shown in background. August 13th, 1932.
1415 Side wall forms under construction to the left. Railroad tunnel No. 2 in the background, on the right. In the foreground are the concrete piers for the steel trestle, which will carry the railroad past the upper portals of Diversion Tunnels No. 1 and No. 2. August 13th, 1932.
1424 A close-up view of a section of the forms used in placing the side wall sections of the concrete lining in the diversion tunnels. August 13th, 1932."