FORMER GLACIATIOX ABOUT THE YOSEMITE. 47 



to a height of about 800 feet above the level of the lake ; its sides, nearly or 

 quite to the summit, ofler abundant traces of glaciation. The contrast be- 

 tween the sharp pinnacles of which the highest points of the Cathedral 

 Peak Range are made up and the rounded and polished surfaces in the 

 valley below is most striking. 



The descent of the Tenaya Fork to the Yosemite is very rapid ; the dis- 

 tance from the lake to the valley being about ten miles, and the difference 

 of elevation fully 4,000 feet. Thick as were the ice-masses at the head of 

 the Tenaya Caiion, the most careful search foiled to reveal any pi-oof that 

 they had ever descended so far as to reach the Yosemite itself. The lower 

 part of the caiion is jiretty much choked up by huge blocks of granite which 

 have tumbled from the adjacent precipitous walls ; but neither the rock in 

 place nor the loose masses exhibited any signs of striation. 



It woiUd appear, therefore, that neither the Mei'ced glacier nor the over- 

 flow of the Tuolumne ever descended so far as the Yosemite ; consequently 

 the ice never entered this valley, as it could only have been supplied to it 

 fiom those sources.* The walls of the Yosemite on each side were carefully 

 examined by the writer without his having been able to find on them any 

 signs of smoothed, striated, or polished surfaces which could be unhesitatingly 

 set down as the work of ice. There are, it is true, many places where the 

 surface of the granite is very even and smooth ; but a close inspection will 

 always be sufficient to establish the fact that this is a structural peculiarity 

 of tlie rock itself, and not of glacial origin. All throughout the Sierra, as 

 has been already mentioned, but especially in the vicinity of the Yosemite, 

 the granitic masses ha\'e a most marked tendency to separate in concentric 

 shells. This structure, which seems to pervade tlie rock to a great depth, im- 

 presses itself most strongly on the scenery, the surface seeming to be covered 

 with a succession of domes and conical Icnobs, some of which, as in the case 

 of Mount Starr King, rise up so steeply as to be quite inaccessible. As these 

 shells or plates separate from each other under the influence of varied me- 



* The statements made by tlie writer in tlie Geology of California, Vol. I., to the effect that a glacier had once 

 tilled the Yosemite Valley, is an error, which has long since been corrected in the various editions of the Yosemite 

 Guide-Book. The mistake was caused by too much dependence being placed on the reports of a.ssistants entirely 

 inexpeiieiiced in the study of glacial phenomena. Since the Geology of California, Vol. I., was jiublished, the 

 Yosemite and the adjacent region have more than once been carefully examined by the writer himself. 



Mr. J. F. Campbell, author of "Frost .and Fire," a practised observer, says, in his work entitled My Cir- 

 cular Notes, "A local geologist found marks which indicate the presence of a large glacier in the Y'oseinite 

 Valley ; I sought carefully, and found no marks of glaciation there." 



