Geology and Botany of Northern Pacific Railroad. 255 



Wright Lake, Goose Lake. etc*., which occupy the points of 

 greatest depression. 



Though much of this great plain has the aspect of a desert, 

 only a small portion of it is absolutely sterile. There is much 

 prairie land covered with a continuous sheet of grass ; and even 

 the more sandy and rocky surfaces have proved to be fairly good 

 grazing ground. It is also true that the attempts to cultivate 

 the soil have been attended with unexpected success, and about 

 Walla-walla, that which was supposed to be a desert surface is 

 producing great crops of wheat. 



The Cascade Mountains. 



Although represented on most maps as an unbroken line of 

 elevation stretching with an almost north and south course from 

 the Californian to the British line, with its hachures looking like 

 an enormously long hairy caterpillar, no just conception is thus 

 given of this broad and compound mountain belt. It is contin- 

 uous with the Sierra Nevada of California ; and it would have 

 been better if they had been designated by a common name. The 

 mountain belt is in Oregon and Washington from thirty to fifty 

 miles in width, consisting of a number of parallel ranges of 

 which the highest is along its eastern border. This is crowned 

 by a series of volcanic cones, Mt. Shasta, Mt. Pitt, Mt. Mc- 

 Laughlin, Mt. Jefferson, Mt. Hood, Mt. Adams, Mt. Eainier 

 (Tacoma), and Mt. Baker, which range from 10,000 to over 

 14,000 feet in height, are all capped with perpetual snow, and 

 form the most impressive group of mountains on the continent. 

 From the California line northward, the material of which these 

 mountain ranges are composed is mainly eruptive in character. 

 The peaks mentioned, and many others, are volcanic vents of 

 which the fires are not yet extinct, and some of them have been 

 in active eruption within a few hundred years. Like the Sierra 

 Nevada, this great fold in the earth's crust was formed after the 

 Triassic and Jurassic, but previous to the Cretaceous age ; and 

 yet, like all other great mountain belts, it has been formed by 

 many additions made at various times. In California, the range 

 is largely composed of granite and other crystalline rocks of an- 

 cient date, flanked by slates which have been proved by the Cal- 

 ifornia geologists to be of Triassic and Jurassic age ; while the 



