A frontal view of the construction of Hoover Dam. The open "slot" down the front of the dam is being filled in with concrete. The slot had been used to carry pipes of ice water to cool the concrete as it hardened.
If you're wondering about permissions and what you can do with this item, a good starting point is the "rights information" on this page. See our terms of use for more tips.
Share your story
Has Calisphere helped you advance your research, complete a project, or find something meaningful? We'd love to hear about it; please send us a message.