46 OSCAR H. HERSHEY 
flowed in an easterly direction and hugged the southern side of 
the valley, there leaving the rock bare of talus or morainic 
material. In receding, it melted away from the warm northern 
side of the valley, and left several successive lateral moraines on 
the valley floor, running lengthwise of it. The last of the series 
is about in the center. A trough shaped depression occupying 
the southern half of the valley indicates the final track of the 
dying glacier.) Init lies some ot gthe wlalelets: | VAN tmibubaigy, 
glacier entered the main trunk at nearly a right angle, and cas- 
caded over a rock-ledge now 500 feet above the main valley 
floor. The ledge is smoothed and striated. Above it a lakelet 
is held behind a moraine composed of clay, sand, gravel and 
bowlders, some of which are beautifully striated. The interest- 
ing feature of this glacier was its evident sensibility to the sun, 
“causing it to melt away from the sunny side of the valley long 
before it disappeared from within the shadow of Tamarack peak. 
The Salmon River glacier—This was seven miles in length, 
one half to one mile in width and 1000 to 1500 feet in depth. 
Its course was a little east of north. It headed at about 6500 
feet of altitude (present), and descended but little below 5500 
feet. On the west of its upper half was the high granite peak 
of Mt. Courtney, whose slope is now bare of loose rocks and soil 
from summit to base and is worn smooth and rounded by glacial 
abrasion. From the precipitous pinnacles of the sawlike crest, 
huge bowlders of granite crashed down upon the ice, and now 
lie scattered upon the floor of the valley and even over the 
opposite slope. Several are as large as an average miner’s cabin. 
Beyond the granite of Mt. Courtney, where the rocks are mainly 
hornblende and mica schists, the upper limit of the glacier is clearly 
defined high on the mountain sides by a sharp line below which 
granite bowlders are numerous and above which there are none ; 
also, by shoulders or small precipices on the inter-ravine spurs 
of the mountain on the east, showing to what height the glacial 
abrasion extended. 
Many prospectors and semi-scientific observers have noted 
the fact that the upper four or five miles of the original main 
