10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 76 



graph of 1922 (pi. 3, fig. 2), exhibits a marked shrinkage and reces- 

 sion. The view of 1902, taken in connection v^ith another of that 

 year (not reproduced) leaves little doubt but that a certain pile of 

 moraine (marked M in the 1922 picture) v^as then in process of 

 formation at the ice lip.^ Assuming this to be true, this pile of moraine 

 being 925 feet distant from the most advanced ice in 1922 allows an 

 estimate to be made of an average retreat of 46 feet per year for the 

 20 years intervening. A distant photograph by the Boundary Survey 

 (pi. 4, fig. i) taken in 1918 plainly shows the presence of this same 

 moraine pile, although the exact position of the ice front in relation 

 to it cannot be satisfactorily fixed. 



The inner slopes of moraine and gravel bounding the open space 

 below the tongue have not had sufficient time, since the ice was near, 

 to develop any forest. A scattering of trees and bushes is growing 

 up, but none have reached large size and there is far from being a 

 continuous mat of vegetation. The 1902 picture above referred to 

 indicates that there has been only a slight increase in the amount of 

 vegetation on these slopes in the score of years intervening. One is 

 probably safe therefore in estimating a lapse of at least half a century 

 since the ice abutted against the banks in question. It was regretted 

 that opportunity was wanting for a detailed study of this question 

 by the cutting of trees. No growth whatever was noticed on the 

 ground moraine of the valley floor below the tongue. The rapid 

 cutting of the migratory glacial streams would perhaps account 

 for this. 



In the test photograph (pi. 2) taken from Station C, three fair- 

 sized stones may be noted near the edge of the ice. These should 

 constitute helpful markers for the future. The one most advanced 

 (H in pi. 2) lies exactly at the ice margin and is located on the accom- 

 panying map of the glacier tongue. It is distant 683 yards from 

 Camp Station and is marked H on the map (fig. 3). 



Drainage streams emerging at several points along the forefoot 

 soon unite in a powerful torrent which cuts off the southeasterly side 

 of the valley and prevents access to the surface of the ice except at 



^ It is possible that the moraine may have been formed in 1897 with almost 

 no retreat between 1897 and 1902, for Professor Collie, at page 56, in his book 

 already cited, states (referring to his visit in 1897), "The snout of the glacier 

 was advancing and plowing up the debris before it." The weakest point in 

 the deduction is the difficulty of identifying the moraine so plainly seen in 

 figure I of plate 3 with that marked in figure 2, but it is the writer's opinion, 

 after examining the place, that they are the same. 



