8o 
ALASKA GLACIERS 
The overturned forest trees associated with the push- 
moraines on the eastern and western shores of the bay and 
on the island, exhibited the same general appearance of 
recency, and there can be little doubt that they were dis¬ 
turbed at the same time. They demonstrate a temporary 
increase in the size of the glacier, not of precisely the 
same amount at all points, but of the same order of mag¬ 
nitude. Previous to that expansion the glacier had been 
smaller during a period at least sufficient for the growth of 
the overturned trees. The evidence from forests and 
push-moraines does not show whether the ice during this 
epoch stood continuously near to the forest or was sub¬ 
ject to wide oscillations in extent; but the bending of 
the moraine belt on the back of the glacier into the 
western embayment (page 73) gives strong support to 
the view that the recent maximum was preceded by an 
important minimum. 
No attempt was made to estimate the age of the trees 
by counting rings of growth, but the forest had the char¬ 
acteristics of maturity, and the time required for its pro¬ 
duction could hardly have been less than two or three 
centuries. The mountain side just west of the glacier, 
rising steeply to a height of 2,000 feet, is clothed with a 
luxuriant growth from the push-moraine up to about 1,500 
feet. Many of the trunks are three or four feet in diam¬ 
eter, and among them lie prostrate logs in a state of de¬ 
cay. Upon the islands, and on the lowland near the east 
margin of the glacier, the trees are somewhat smaller, but 
the many dead trunks standing among them indicate that 
they are mature, and their term of life may be as long as 
that of their western neighbors. 
A further item of information as to variation, albeit 
somewhat indefinite, may be derived from Vancouver’s 
map. It is not sufficiently precise to afford identification 
of any topographic detail of the bay except Heather Island 
