THE TWIN LAKES GLACIATED AREA 311 



Range, where the head-feeding valleys of the glacial streams were 

 working against each other, cirque action was general, sharp forms 

 prevail, and the general view looking west toward the divide from 

 any high point near the Arkansas shows a sea of sharp peaks. The 

 multiplication of tributaries back in the range leaves scarcely any 

 part untouched by glacial action. Fig. 14 is a view taken looking 



Fig. 13 — Summit of Lost Canyon Mountain, with the upper edge of Boswell 

 Gulch cirque on left. 



across Lake Creek toward La Plata Peak (14,342 feet), and shows 

 something of the character of the area where little preglacial surface 

 is left, the ridge in the foreground on the right being the only pre- 

 glacial surface in the view which shows. About Twin Lakes, and 

 nearer the border of the valley, there are considerable areas in which 

 the two types of topography resulting from the two agencies occur 

 together, since here the drainage of the tributaries of the Arkansas is 

 concentrated in trunk channels of their lower course. The general 

 form of Lost Canyon Mountain as seen from the Arkansas valley has 

 been mentioned. Fig. 13 shows the evenly rounded summit of pre- 



