GLACIATION OF THE ALASKA RANGE 437 
size than the present ones, but the ice fields there were never 
equally extensive with those on the south. The present 
distribution of glaciers shows the same contrast between those 
on opposite sides of the range, but the discrepancy is not so 
great now as formerly. In the vicinity of Mount Hayes this 
difference is least well marked, the ice tongues draining to the 
Tanana being only slightly smaller than those at the head of the 
Susitna. None of the earlier glaciers north of Mount Hayes reached 
more than 30 miles farther than the present ice edge, while south of 
this mountain the glaciers extended more than 200 miles beyond 
the present terminations. From the facts available in regard to 
this point, the glaciers of the Alaska Range seem in general to be in 
a state of retreat. Several large glaciers southeast of Mount 
McKinley are exceptions to this rule and are either advancing or 
have remained about stationary for a time sufficiently long to allow 
good-sized trees to grow in their paths. 
The Alaska Range offers a wide range of types and a great num- 
ber of examples of the many forms of valley glaciers, and offers an 
attractive and practically untouched field for the student of glacial 
phenomena. 
