A Progress picture of the construction. Once a month, a camera was placed in exactly the same position, always taking identical views.

There were four elevator houses across the dam. They went deep down inside of the dam to walk-ways that provide access to internal Dam equipment. These tunnels also formed part of the cooling system for the dam.

Concrete puts off a lot of heat as it hardens. The dam contains millions of square yards of concrete, making it so massive that without some kind of cooling system it would take centuries for it to cool down and cure. The secondary function of the tunnel system was as a cooling system for curing concrete.