STUDIES OF THE CYCLE OF GLACIATION Be 
In the Glacier Park district the Pleistocene glaciers occupied 
the entire valleys within the range and spread out eastward their 
aprons of Piedmont type. They also extended westward a long 
distance down the valley of the Flathead River." 
It is here proposed to use the term monumented upland to 
describe the extreme type of mountain sculpture which is repre- 
sented in the Glacier National Park and which is believed to be due 
to continued glacial action upon a fretted upland like that of the 
Alps. Cirque enlargement carried to this stage has sapped the 
Fic. 4.—View of Reynolds Mountain, a characteristic monument of the Glacier 
National Park region. View taken from the trail to Piegan Pass. 
main comb ridge so as to largely obliterate the azgualle type of 
crest or aréte (Fig. 6 shows one of the remaining comb ridges). 
Matterhorns have in the process been reduced in size as the cols 
are progressively lowered and widened and are transformed into 
arétes. ‘The last remnants of the upland to be removed by this 
continued cirque enlargement are found away from the original 
divide and outward toward the flanks of the upland, for the reason 
that in their later stages cirques enlarge excessively on their lateral 
walls. A good illustration of this tendency is supplied by the 
t Wm. C. Alden, ‘‘Pre-Wisconsin Glacial Drift in the Region of Glacier National 
Park,” Bull. Geol. Soc. Am., Vol. XXIII (1912), Pl. 37. See also by same author, 
“Glaciers of Glacier National Park,’ and especially the map opposite p. 32. 
