The Hoover Dam is an iconic American landmark, yet within its massive walls lie tales long buried. From harrowing accounts of the men who built it, to the shocking ways they were kept in danger. There were explosive ideas on how to make a dam so large, and even more incredible ways to protect it. From the Colorado River to California's Salton Sea, Henry's journey to find unknown facts about the Hoover Dam is as colossal as the structure itself.