THE GREAT SIERRA NEVADA FAULT SCARP. 611 



theless 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 canons issue numerous streams util- 

 ized for irrigating the valley; the eastern range, on the contrary, 

 is comparatively barren, snow lies on it but a short time, and run- 

 ning 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 



Sierra Nevada from the Lone Pine Hills. 



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 car- 

 bonates of soda crystallize out first, and are thus easily separated 



