28 THE MOUNTAINS OF CALIFOBNIA 



chiefly porous lavas subject to comparatively rapid 

 waste. The ancient moraines also, though well 

 preserved on most of the south half of the range, 

 are nearly obliterated to the northward, but their 

 material is found scattered and disintegrated. 



A similar blurred condition of the superficial rec 

 ords of glacial action obtains throughout most of 

 Oregon, Washington, British Columbia, and Alaska, 

 due in great part to the action of excessive mois 

 ture. Even in southeastern Alaska, where the most 

 extensive glaciers on the continent are, the more 

 evanescent of the traces of their former greater ex 

 tension, though comparatively recent, are more ob 

 scure than those of the ancient California glaciers 

 where the climate is drier and the rocks more re 

 sisting. 



These general views of the glaciers of the Pacific 

 Coast will enable my readers to see something of 

 the changes that have taken place in California, and 

 will throw light on the residual glaciers of the 

 High Sierra. 



Prior to the autumn of 1871 the glaciers of the 

 Sierra were unknown. In October of that year I 

 discovered the Black Mountain Glacier in a 

 shadowy amphitheater between Black and Eed 

 Mountains, two of the peaks of the Merced group. 

 This group is the highest portion of a spur that 

 straggles out from the main axis of the range in the 

 direction of Yosemite Valley. At the time of this 

 interesting discovery I was exploring the neve am 

 phitheaters of the group, and tracing the courses of 

 the ancient glaciers that once poured from its ample 

 fountains through the Illilouette Basin and the 



