![A man stands inside of a penstock pipe, used during the construction of the Hoover Dam. The 30-foot diameter pipes dwarf the worker, and shows the grand scale of the project. In fact, there is enough concrete inside the dam to pave a two-lane highway from San Francisco, Calif. to New York, N.Y.](http://media.lasvegassun.com/media/img/photos/2008/04/22/scaled.1347_hoover_dam019_t653.jpg?214bc4f9d9bd7c08c7d0f6599bb3328710e01e7b)
UNLV Special Collections
A man stands inside of a penstock pipe, used during the construction of the Hoover Dam. The 30-foot diameter pipes dwarf the worker, and shows the grand scale of the project. In fact, there is enough concrete inside the dam to pave a two-lane highway from San Francisco, Calif. to New York, N.Y.