GLACIER OF MT. ARAPAHOE, COLORADO 653 



mass I descended for about a mile but discovered no unquestioned 

 evidences of movement of the ice. Between this and the edge 

 of the greater mass to the west, a large ridge of debris has been 

 formed. The ridge is inconspicuous at its inception near the 

 upper end of the smaller ice field, but farther down it increases 

 in size until near the outlet of the cirque it assumes notable pro- 

 portions. In former times the upper part of this ridge now 

 separating the two snow fields, was probably a medial moraine. 

 But the recession of the ice has changed it into a terminal 

 moraine throughout the greater part of its length. The ridge is 

 crescent shaped and conforms rather closely to the edge of the 

 ice. It has two more or less distinct crests — an outer large one, 

 and an inner small one. Between the smaller crest and the edge 

 of the ice, is a well defined trough. 



There is a shallow lake a short distance below the edge of 

 the ice. From an eminence on which I stood looking down upon 

 this lake, I noticed that the current, produced by the stream 

 flowing into it from the ice above, could be plainly traced for 

 several rods by its whiteness which was presumably due to the 

 rock flour derived from the ice above. This was not present in 

 sufficient quantity to attract my attention in the running stream. 

 But the contrast in coior as the whitened water of the stream 

 entered the green water of the lake was conspicuous. Closer 

 inspection strengthened the conclusion that the stream carried 

 rock flour. 



The size of the ice mass ; its great though unknown depth ; 

 the steep inclination of its surface ; its stratification and crevasses; 

 its terminal moraine ; and the rock flour of its stream, all point 

 to the inference that this field of snow and ice constitutes a true 

 glacier. 



The valley into which the cirque opens is one of broad bot- 

 tom and precipitous sides. The side walls are nearly vertical in 

 many places. Its floor is occupied by a chain of lakes inter- 

 rupted in several places by groups of poorly formed roches 

 moutonnees. Most of the lakes are in rock-hewn basins, but 

 some are formed back of debris dams. One in particular, near 



