Black and white image showing a river-level view of canyon blasting in Black Canyon at the site of Hoover Dam construction. Note: Boulder Dam was officially renamed Hoover Dam in 1947.
Cofferdam (upper one), 1/4 - 1/2 mile upstream from Dam site. Dec. 25, 1932. Note on back: ""Electric Marion steam shovel on top of cofferdam. May have used shovel to lay down metal grating. - W. A. Davis.""