Accordingly a canal extending twenty miles up the river was constructed; with a two-hundred-and-twenty-foot drop it was capable of delivering water enough to generate four thousand two hundred horse-power. A mill was built and an electric plant installed which ran the mill and machine shops besides furnishing power for laying the heavy stones, lighting the works and town, and leaving a large surplus amount for pumping water from numerous wells in the Salt River Valley fifty miles away. By the economy of self-manufacturing, the cost of the cement to the government was but two dollars per barrel, thereby making a saving of nearly half a million dollars. [Illustration: Shoshone Project, Wyoming Shoshone Canyon, looking upstream toward the dam. Dam, 328.4 feet high; storage capacity, 456,000 acre-feet] To provide proper accommodations for all of the employees and their families, a regular town was built on the floor of the reservoir, to be submerged when the works should be completed and the flood gates closed. The town, which was christened Roosevelt, contained a population of upward of two thousand, and bore the reputation of being the best behaved in all Arizona. The dam, also named after Colonel Roosevelt, then President of the United States, floods two valleys, one twelve and the other fifteen miles long and each from one to three miles wide. The reservoir is nearly two hundred feet deep on the average. It is two hundred and eighty feet high, and the thickness of the dam ranges from one hundred and seventy-five feet at the bottom to twenty feet at the top, where its length is one thousand and eighty feet. Massive iron gates weighing sixty thousand pounds guard the outlet of the flood. To do the preliminary work and construct the dam nearly eight years were required, and during a part of this time a thousand men were employed both night and day, several hundred of whom were Apache Indians. This region was previously the haunt of Chief Geronimo and his murderous band of Apaches. Near by are two groups of cliff dwellings formerly occupied by a race now extinct. The capacity of this immense reservoir exceeds that of the Nile pent up by the Assouan dam, and the water would be sufficient to fill a canal two hundred feet wide and twenty feet deep, extending entirely across the United States from the Atlantic to the Pacific. When full there is sufficient water to submerge the city of Washington to the depth of thirty-four feet.