82 THE MOUNTAINS OF CALIFORNIA 



across the Sierra, above Donner Lake; but for 

 every pound of rock moved in this way, the gla 

 ciers which descended east and west through this 

 same pass, crushed and carried away more than 

 a hundred tons. 



The so-called practicable road-passes are simply 

 those portions of the range more degraded by 

 glacial action than the adjacent portions, and de 

 graded in such a way as to leave the summits 

 rounded, instead of sharp; while the peaks, from 

 the superior strength and hardness of their rocks, 

 or from more favorable position, having suffered 

 less degradation, are left towering above the passes 

 as if they had been heaved into the sky by some 

 force acting from beneath. 



The scenery of all the passes, especially at the 

 head, is of the wildest and grandest description, 

 lofty peaks massed together and laden around their 

 bases with ice and snow ; chains of glacier lakes ; 

 cascading streams in endless variety, with glorious 

 views, westward over a sea of rocks and woods, 

 and eastward over strange ashy plains, volcanoes, 

 and the dry, dead-looking ranges of the Great Ba 

 sin. Every pass, however, possesses treasures of 

 beauty all its own. 



Having thus in a general way indicated the 

 height, leading features, and distribution of the 

 principal passes, I will now endeavor to describe 

 the Mono Pass in particular, which may, I think, 

 be regarded as a fair example of the higher alpine 

 passes in general. 



The main portion of the Mono Pass is formed 



