AMERICAN 



JOURNAL OF SCIENCE AND ARTS. 



[THIRD SERIES.] 



by Ci 



tains of the Pacific Shpe; by Clarence Kikg, U. S. Geologist 



Western explorers have usually confined their labors to the 

 fi'^T-e accessible altitudes ; indeed it is only within the last ten 

 ' ;st have be 



. .__ elevations 



the absence of glaciers. Wide areas of mountains whose aver- 

 age altitude and configuration are equivalent to the glacier- 

 bearing mountains of Switzerland have been found to be 

 covered here and there by deep fields of perpetual snow, simi- 

 lar m character to the neve of the Alps. The whole topogra- 

 phy of the loftier Cordillera within the United States has been 

 modified by glaciers now extinct: vast moraines flank the 

 higher gorges; accumulations of gravels and sands, erratics, 

 roches montonnees, and the finest possible instances of polished 

 rock abound wherever a considerable : ^ -' '" '''^'''' 



— J thousand feet It is almost startling to observe the 

 ireshness of these indications. Travel where one will in the 

 ^igh Sierras or in the more elevated regions of the Eocky Moun- 

 ^uis, he seems to be treading the pathway of a glacier of 

 yesterday. A future study will, without doubt, clear up the 

 entire chronological relations of the ice occupation of these 

 ^nges. The studies of Professor Whitney and his corps in 

 ^ne heights of the Sierra Nevada have developed a series of 

 extinct glaciers equaling in all respects the former grandeur of 

 t^e Alpine system: yet with the exception of one or two 

 rudimentary masses of ice, nothing is left in the Sierras but 

 ^- Jour. Sci.-Third Series, Vol I, No. a-MABCH, 1871. 



