The construction of the Hoover Dam. Concrete forms slabs to build the dam's structure, visible below the downstream face of the dam, while intake towers rise behind the dam.
A group of men pose for a photo at an unidentified event. Robert Woodruff, center front, wears a dark suit. Behind him, looking over his right shoulder, is Mike O'Callaghan. The other men are identified on the back of the photo.