Men stand inside a diversion tunnel at the Hoover Dam. The Hoover Dam was called the Boulder Dam until 1947. "BDRA. NEV. 4.36 341" is written at the top of the photo. Site Name: Hoover Dam (dam)
Diversion Tunnel No. 3 nearly completed. Sept. 1, 1932. "Asphalt visible on ceiling. Fill on Floor & rails have to be removed prior to use for water diversion. Tunnel is completed except for fill removal." W.A. Davis, 1992
View looking out of diversion tunnel, diameter 56' or more, inside finish 50'. Note on back: "Tunel is on Nevada side. Tunnels had compressed air lines and electricity installed Marion electric steam shovel. - W. A. Davis, 1992."
Looking into diversion tunnel. (Rig. Inside) Note on back: "Inside diversion tunnel, looking down 30 ft. tunnel to the power house. Tunnel lined with steel. Air hammer scars on the perimeter. Arizona side. - W. A. Davis, 1992."