In 1933, an ambitious project was underway in the middle of the desert on the Arizona-Nevada border. Dozens of men dangled from long ropes along the tall canyon walls hundreds of feet above the Colorado River. The workers used jackhammers to drill holes into the rock, and then placed dynamite into each hole. Boom Boom Boom This dangerous--and sometimes deadly--work was just the beginning of the construction of the Hoover Dam. The Hoover Damtraces...