Keywords: HooverDamHighScaler.jpg en wikipedia 2011 March 23 High scalers drilling into canyon wall 500 feet above the Colorado River in Black Canyon site of Hoover Dam 1932 http //www usbr gov/lc/hooverdam/images/WashNo01333 jpg Bureau of Reclamation PD-USGov Original upload log en wikipedia NortyNort CommonsHelper page en wikipedia Hooverdamhighscaler jpg 2010-06-20 13 52 NortyNort 500×396× 54898 bytes <nowiki> High scalers drilling into canyon wall 500 feet above the Colorado River in Black Canyon site of Hoover Dam 1932 http //www usbr gov/lc/hooverdam/images/WashNo01333 jpg ~~~~~ </nowiki> People associated with the construction of Hoover Dam workers high scalers 1932 in the United States |