Shovel excavation of a blasted rock cut along the edge of Black Canyon for the Government Highway. (June 2, 1931)

Six Companies railroad grade below Cape Horn, Black Canyon. (8-9-31)

Six Companies railroad grade above railroad tunnel No. 1 showing the proposed location of the "low-mix" concrete mixing plant. (8-9-31)

Boat landing at railroad tunnel No. 1 and the catwalk to the Arizona side of Black Canyon. (8-9-31)

Inside of black album cover

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.3 #888 Lower portals of Diversion tunnels No.3 and 4 during flood. Feb. 10, 1932 p.3 #896 Bucyrus Erie 43-B gas-air shovel was the only piece of equipment caught by the flood. Feb. 10, 1932. p.3 #884 Looking across river at lower portal of Diversion Tunnel No.3. Feb 10, 1932 p.3 #897 Looking across river from Arizona side at upper portals of diversion tunnels No.1 and 2. Truck bridge in foreground has been partially washed out. Feb. 10, 1932.