Black Canyon of the Colorado the Nevada side of the canyon is the Sauna Cave. This cave was drilled by miners working on Hoover Dam while it was being constructed. It is a deep cave with calcium carbonate crystals on the walls. At the end of the cave is a hot spring, which causes temperatures in the cave to reach . One prominent canyon that splits from this canyon south of the Hoover Dam is Boy Scout Canyon. Boy Scout Canyon has water running through it that is warmed from a geothermal source. On the Arizona side of the river, there are several large hot
Glen Canyon Dam be about . The general consensus among inhabitants of the Colorado River basin and government officials was that a high dam had to be built on the Colorado to control floods and provide carry-over water storage for times of drought. Possible locations for this dam were debated for years, and in fact the Bureau of Reclamation's first study for a dam at Glen Canyon was made in 1924, in addition to studies for locations at Black and Boulder Canyons lower on the Colorado, below Grand Canyon. These studies found that the lower Colorado sites had stronger foundation rock which might