(4:56) b/w sound
Shows the Colorado River, electric power transmission lines, and a steel plant in operation. A train brings materials, fuel, and workmen to Boulder City to build Boulder Dam. Close-ups are shown of buckets on cable cars dumping cement into the coffer dam. Includes views of the power lines and towers at the dam site, the switches to control the power, and the completed dam; and the farms, homes, and orchards made possible by power and water from the dam.