EXISTING GLACIERS. 21 



begin to appear in the Sierra Nevada Mountains, in the 

 vicinity of the Yosemite Park, in central California. Here 

 the conditions necessary for the production of glaciers are 

 favourable, namely, a high altitude, snow-fields of consid- 

 erable extent, and unobstructed exposure to the moisture- 

 laden currents of air from the Pacific Ocean. Sixteen 

 glaciers of small size have been noted among the summits 

 to the east of the Yosemite ; but none of them descend 

 much below the eleven-thousand-foot line, and none of 

 them are over a mile in length. Indeed, they are so small, 

 and their motion is so slight, that it is a question whether 

 or not they are to be classed with true glaciers. 



Owing to the comparatively low elevation of the Sierra 

 Nevada north of Tuolumne County, California, no other 

 living glaciers are found until reaching Mount Shasta, in 

 the extreme northern part of the State. This is a volcanic 

 peak, rising fourteen thousand five hundred feet above 

 the sea, and having no peaks within forty miles of it as 

 high as ten thousand feet ; yet so abundant is the snow- 

 fall that as many as five glaciers are found upon its north- 

 ern side, some of them being as much as three miles long 

 and extending as low down as the eight-thousand-foot 

 level. Upon the southern side glaciers are so completely 

 absent that Professor Whitney ascended the mountain 

 and remained in perfect ignorance of its glacial system. 

 In 1870 Mr. Clarence King first discovered and described 

 them on the northern side. 



North of California glaciers characterise the Cascade 

 Range in increasing numbers all the way to the Alaskan 

 Peninsula. They are to be found upon Diamond Peak, 

 the Three Sisters, Mount Jefferson, and Mount Hood, in 

 Oregon, and appear in still larger proportions upon the 

 flanks of Mount Rainier (or Tacoma) and Mount Baker, 

 in the State of Washington. The glacier at the head of 

 the White River Valley is upon the north side of Rainier, 

 and is the largest one upon that mountain, reaching 



