[Illustration: SIX YEARS FROM DESERT LAND
A rich and fruitful farm on land barren in 1912]
In northern Wyoming, near the eastern entrance to Yellowstone National Park, the South and North Forks of Shoshone River plunge downward from the steep slopes of the Rockies and unite in a broad level-floored valley which in early geological times was a beautiful mountain lake. At the lower end of the valley the river rushes abruptly into a deep and narrow canyon. The entrance to the canyon, which is only sixty feet wide at the bottom, was selected as the site for the Shoshone dam. Before construction began it was necessary to blast a highway through the gorge for a distance of eight miles, in order to connect the work with the nearest railway. This highway is now a part of the road system into the Park, and is known as Cody Way.
Nearly a year was spent in investigating bed rock conditions before the foundation was placed. Enormous boulders eighty feet in thickness were discovered in the bed of the stream; the removal of these, owing to the narrowness and depth of the canyon, proved expensive and difficult. Before any work was undertaken in clearing the channel of obstructions, the river was passed around the dam site by means of a tunnel. During the early period of construction the laborers were taken to and from their work, hundreds of feet below the camp, by means of baskets, and skips were suspended on cable ways across the gorge. Sudden floods, extreme cold weather, short seasons, and other unfavorable conditions greatly retarded progress.
The dam is a wedge of concrete, with curve up stream, 328 feet in height, and 200 feet long on top. It has restored the lake of olden times, and this beautiful body of water is now one of the attractions of the trip to the Park. The stored water will be utilized for the irrigation of 150,000 acres of land on the mesa (a high, broad, flat table-land) below Cody. This region until 1907 was a worthless and uninhabited desert. Today it is occupied by more than 700 farm families and three growing towns.
[Illustration: LAGUNA DAM, ARIZONA-CALIFORNIA
Length, 4781 feet; 19 feet high. Division Gates, 17×33 feet, are the largest in the world]
The delta of the Colorado River, in Arizona and California, is often described as America’s Valley of the Nile. In climate, soil and agricultural conditions it is singularly like the great valley of Egypt. The conquest of this turbulent river of the West was a splendid achievement. The engineering features of the Yuma project, in Arizona and California, are in many respects original. The control of the stream called for a long diversion dam and more than 100 miles of strong levees. The dam is nearly a mile long, nineteen feet high, and 267 feet wide on the bottom. Its type is similar to that of the barrages of the English engineers in India. Laid on a foundation of shifting sand and silt, it is held in place by its enormous weight, 600,000 tons. Owing to the quantities of silt carried by this stream, the dam is provided with a large settling basin, sluiceway and gates, by which comparatively clear water is turned into the canals. The main canal system extends for twelve miles on the California side. Just opposite the city of Yuma, Arizona, the entire volume, 1,000 cubic feet per second, is dropped in a siphon 1,000 feet long and carried under the river to the Arizona side. Here are 90,000 acres of valley and mesa land, and more than half of the area is being developed intensively. The soil is of great depth and extremely fertile, and the climate is adapted to the growing of a wide variety of crops. The mesa lands which are to be opened later are described as frostless, and especially adapted to growing citrus and other semi-tropic crops.