The work had to be carried out under the most difficult and adventurous conditions. The men of the Reclamation Service were in the truest sense pioneers, building great engineering works far from the railroads, where the very problem of living for the great numbers of workers required was no simple one. On the Shoshone in Wyoming these men built the highest dam in the world, 310 feet from base to crest. They pierced a mountain range in Colorado and carried the waters of the Gunnison River nearly six miles to the Uncompahgre Valley through a tunnel in the solid rock. The great Roosevelt dam on the Salt River in Arizona with its gigantic curved wall of masonry 280 feet high, created a lake with a capacity of fifty-six billion cubic feet, and watered in 1915 an area of 750,000 acres. The work of these bold pioneers was made possible by the fearless backing which they received from the Administration at Washington. The President demanded of them certain definite results and gave them unquestioning support. In Roosevelt's own words, "the men in charge were given to understand that they must get into the water if they would learn to swim; and, furthermore, they learned to know that if they acted honestly, and boldly and fearlessly accepted responsibility, I would stand by them to the limit. In this, as in every other case, in the end the boldness of the action fully justified itself." The work of reclamation was first prosecuted under the United States Geological Survey; but in the spring of 1908 the United States Reclamation Service was established to carry it on, under the direction of Mr. Newell, to whom the inception of the plan was due. Roosevelt paid a fine and well-deserved tribute to the man who originated and carried through this great national achievement when he said that "Newell's single-minded devotion to this great task, the constructive imagination which enabled him to conceive it, and the executive power and high character through which he and his assistant, Arthur P. Davis, built up a model service--all these made him a model servant. The final proof of his merit is supplied by the character and records of the men who later assailed him."