Page:Popular Science Monthly Volume 52.djvu/631

Rh possess remarkable proportions, rising five thousand to eight thousand feet above the valley and terminating in White Mountain peak, with an altitude of more than thirteen thousand feet. It will thus be seen that Owen's Valley occupies a troughlike depression between two parallel earth ridges or fault blocks. It also divides the arid from the non-arid regions. The crests of the two ranges are but eighteen miles apart, with this depression nearly two miles deep between them. The western wall is white with snow much of the year, and from its rugged cañons issue numerous streams utilized for irrigating the valley; the eastern range, on the contrary, is comparatively barren, snow lies on it but a short time, and running streams reaching the valley are rare. Owen's Lake lies toward the south at the lower end of the valley. Its greatest diameter is about eighteen miles, but it has no outlet and is quite shallow. It is probable that at one time its waters emptied southward through the continuation of this fault valley into the great wastes of the Salt Wells Desert. The water of the lake is impregnated with sodium



chloride, sodium carbonates, and sulphates. The soda is present in such large amount that it is obtained in commercial quantities. When the water is evaporated in shallow ponds or tanks the carbonates of soda crystallize out first, and are thus easily separated