e Colorado River , most
             importantly, had to be diverted. Four diversion tunnels were cut over a period of a year
             through the bedrock of Black Canyon. A temporary dam was constructed which
             diverted the water into the diversion tunnels. Meanwhile, the loose rock had to be
             removed from the canyon walls. Special men were required for the job, they were
             called "high-scalers." They had to climb down the canyon walls tied to ropes. The
             high-scalers used jackhammers and dynamite to strip away the rock. The men who
             chose to do this work came from many backgrounds. Some were former sailors, some
             circus acrobats, others were American Indians. All of them had to be agile men,
             unafraid to swing out over the canyon hanging by a rope. It was hard and dangerous
             work, perhaps the most physically demanding work on the entire project. They scaled
             the walls with a forty-four pound jack hammer chipping away at the rock and then
             placing dynamite around boulders too large to demolish by hand. The scaler's had to do
             all this while moving about, avoiding live air hoses and electrical lines, it was not
             For all men on the job the danger of being hit from falling rocks and dropped
             tools was the most common cause of death during the building of the dam. Ninety- six
             men were killed in industrial accidents while building the dam. So for their own
             protection the men started making improvised hard hats for themselves by coating cloth
             hats with coal tar. These "hard-boiled hats," were extremely effective when being hit
             by falling objects. The Six Companies eventually distributed commercially made hard
             hats and issued one to every man on the project.
             The risk and high visibility of the job gave it a certain status which appealed to
             some types of men. When the formen were not looking, these men would often swing
             out from the cliffs and attempt stunts, in competition with other scalers....