84 I. C. RUSSELL — HANGING VALLEYS 



the upper 4 or 5 miles of its course. The canyon is comparatively 

 straight, and is simple in its topography. In its upper portion its bold 

 northern border is a great precipitous wall, without lateral valleys or 

 alcoves, but its southern border is conspicuously irregular and has four 

 or five cirque-like hanging valleys arranged along it and about 1,000 feet 

 above its bottom. These hanging valleys are less typical than in many 

 other instances, and at their mouths the main valley widens and the 

 steep descents leading from them to the receiving valley are within 

 recesses, and do not form a part of the main wall of the larger valley. 

 At the present time the snow melts in the main valley, even at its head, 

 each summer, but lingers so as to form perennial banks in the cirque of 

 each of the tributary hanging valleys on its southern wall. 



The question is : Was Kieger canyon in existence previous to the for- 

 mation of glaciers on Stein mountain, and does the evidence point to 

 deep stream dissection of the mountain before glaciers appeared, or was 

 it excavated entirely by the glacier that occupied it, less the insignificant 

 amount of post-Glacial stream erosion that has occurred? 



The facts most suggestive in this connection are : Kieger canyon is 

 prolonged for some 20 miles below the locality where the lowest evidence 

 of glaciation is discernible, and is not floored with coarse debris, such as 

 occurs dowmstream from the extremities of existing valley glaciers. No 

 alluvial terraces are present to show that conspicuous variations in the 

 load of Kieger creek have occurred, such as are present in many valleys 

 which have held glaciers in their higher tracts. There are no recogniz- 

 able terminal moraines anywhere in the canyon and almost a complete 

 absence of lateral moraines. The evidence of the former presence of a 

 glacier in the upper end of the canyon is furnished principally by a 

 noticeable increase of width in the portion formerly occupied by ice and 

 a change from nearly vertical walls to an U-shaped cross profile. 



If we assume that Kieger canyon owes its depth below its hanging 

 valleys to ice erosion, it must be remembered that its chief supply of ice 

 came from the small glaciers on its southern side, as there is no well- 

 defined cirque at its head and no other gathering ground for snow, except 

 the nearly straight and unbroken surface of its precipitous northern 

 wall — that is, the highest lateral glacier was enabled to excavate a val- 

 ley some 300 or 400 feet deep, but on turning at right angles to its upper 

 course and being reinforced to a slight extent by the snow in Kieger 

 canyon, above where the change in direction occurred, it was at once 

 enabled to erode a canyon to a depth of 1,000 feet. Such an assumption, 

 while called for by the hypothesis of differential ice erosion to account 

 for hanging valleys, does violence to what is known to be the habit, so 

 to speak, of glaciers and is manifestly untenable. 



