National reclamation was the dream of Western statesmen and thinkers for a quarter of a century before a laggard Congress gave it form and actuality by the law of June 17, 1902. With the passage of that law and another which initiated the construction of the Panama Canal,--both were signed by President Roosevelt in the same month,--the engineering forces of the nation were flung into widely differing fields of activity. With the Panama Canal engineers, the task, though herculean, was confined to a restricted and perfectly well defined area. On the other hand, the Reclamation problems were generally in regions widely separated, remote from transportation, and often unsurveyed and unexplored. To appreciate the variety and magnitude of the tasks involved, it is necessary briefly to describe the general character of the country in which these works were projected. _The Desert States_ The great American desert may be roughly described as lying between the western boundary of the Mississippi Valley and the Pacific Ocean, and as embracing about two-fifths of the total area of continental United States, exclusive of Alaska. The superficial area of the several states that comprise this desert is almost equal to the combined areas of Norway, Sweden, Denmark, Holland, Germany, Belgium, France, Italy, the British Isles, Austro-Hungary, Spain, Portugal, the Balkan States, Turkey in Europe, and Japan. The population of the so-called desert states[A] is 16,423,625, while that of the countries above-mentioned is over twelve times as great. Within the confines of the desert is every gradation of climate from north temperate to semi-tropic found in these European countries. Its physical geography includes a wide variety of features from the Great Plains to the highest and lowest elevations in our country. Herein are found the most notable scenic attractions, including the great national playgrounds of Yellowstone, Glacier, Rocky Mountain, Mount Rainier, Crater Lake and Yosemite National Parks, the Grand Canyon of Arizona, and the principal national forests. [A] Arizona, New Mexico, California, Oregon, Washington, Nevada, Utah, Idaho, Montana, Colorado, Kansas, Nebraska, North and South Dakota, Oklahoma. [Illustration: THE FIRST FLOW OF WATER In Grand Valley Project, Colorado]