On the Colorado river. This dam resulted in the formation of Lake Powell, which has become a tourist destination. The city of Page came into existence during the construction of the dam. The fact that the city is quite young (relatively speaking) becomes obvious when you pay it a visit.

The dam is quite impressive. The Carl Hayden Visitor Center beside the dam is run by the Bureau of Reclamation. It has lots of interesting information.
https://en.wikipedia.org/wiki/Glen_Canyon_Dam

The bridge is among the highest bridges in the US.
https://en.wikipedia.org/wiki/Glen_Canyon_Dam_Bridge