Black and white image of diversion tunnel #2 on the Nevada side of Hoover Dam. This image shows the groundwork for the tunnel. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Black and white image of concrete being placed into the side walls of diversion tunnel #4 at Hoover Dam. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Black and white image of concrete being placed into the side walls of diversion tunnel #4 at Hoover Dam. Note: Boulder Dam was officially renamed Hoover Dam in 1947.