Archival objects in this container: View of lower-level concrete mixing plant with Mack trucks in the foreground (1 of 3 views): photographs, approximately 1932 Excavation of lower diversion tunnels: photographs, approximately 1932 View of lower-level concrete mixing plant with Mack truck on the right, telephone lines visible in the background (2 of 3 views): photographs, approximately 1932 View of lower-level concrete mixing plant and Mack trucks on Nevada side (3 of 3 views): photograph, approximately 1932 View of lower-level concrete mixing plant, Mack trucks, and other unlabeled buildings from opposite direction: photographs, approximately 1932 View of upper-level construction area with Mack trucks parked outside a building, other buildings visible in the distance: photograph, approximately 1932 Lower-level construction area next to river with buildings and Mack trucks; small structures visible across the water: photographs, approximately 1932 Downstream face of dam under construction with two intake towers visible in background: photograph, approximately 1932 Upstream view of dam under construction with two intake towers under construction in foreground: photograph, approximately 1932 Mack truck crossing temporary steel suspension bridge immediately below lower portals of diversion tunnels: photographs, approximately 1932