is a glacier lake. Their basins were not merely 

 remodeled and scoured out by this mighty agent, 

 but in the first place were eroded from the 

 solid." The Rocky Mountain lakes are set deep 

 in canons, mounted on terraces, and strung like 

 uncut gems along alpine streams. The boulders 

 in many of their basins are as clean and new as 

 though just left by the constructive ice. 



These lakes are scattered through the high 

 mountains of Colorado, the greater number 

 lying between the altitudes of ten thousand and 

 twelve thousand feet. Few were formed above 

 the altitude of twelve thousand, and most of 

 those below ten thousand now are great flower- 

 pots and hold a flower-illumined meadow or a 

 grove. Timber-line divides this lake-belt into 

 two nearly equal parts. Many are small tarns 

 with rocky and utterly wild surroundings. Cir- 

 cular, elliptical, and long, narrow forms pre- 

 dominate. Some lie upon a narrow terrace along 

 the base of a precipice. Many are great circular 

 wells at the bottom of a fall ; others are long and 

 narrow, filling canons from wall to wall. 



Glaciers the world over have been the chief 

 150 



