120 GUIDEBOOK OF THE WESTERN UNITED STATES. 
the mouth of Elk Creek the traveler, by looking back on the 
west (left) may see high rugged peaks coming one by one into view. 
Mount Jackson may be seen by looking up Cross Creek, but the one 
peak which he desires to see more than all others is hidden for a long 
time by the high plateau on the south side of the canyon. Finally, 
however, after crossing Elk Creek, which comes in from the 
east, when the train is near milepost 300 and just before it passes be- 
hind a ridge on the left, the traveler may catch a glimpse up the creek 
valley of the Mount of the Holy Cross (see Pl. LIIT), but even 
here the cross itself is not well shown. Very few persons who have 
passed over this road have been able to identify this famous peak, 
but if the traveler will look as directed he can certainly see it unless 
the atmospheric conditions prevent a view of 
any of the high mountains. 
Just after milepost 300 is passed the moraine 
glacier appears across the river as a sharp and 
distinct ridge which curves parallel with the 
railroad, and a good view of its tree-covered 
slopes may be had from the train. This moraine 
is composed of sand, clay, gravel, and boulders 
brought down by the ice from the high moun- 
tains on the west, and the glacier that brought 
this great mass of material marked the last 
stage of glaciation (Wisconsin) that affected 
North America; but half a mile beyond mile- 
seca eure aE post 300 there is on the west (left) another ridge 
moraines above Min. OF Moraine that is rudely parallel to the other 
ridge just described, but sharply distinct from 
it. This outer moraine was evidently formed 
long before the last glacier occupied the valley, for its slopes are 
more affected by the weather, and as it is outside of the other moraine 
it must have been formed earlier or else the ice would have de- 
molished the inner ridge, which now is the more conspicuous of the 
two. The relative position of the two moraines is shown in figure 
30. The existence of this older moraine shows clearly that glaciers 
were formed in these mountains in at least two distinct epochs of 
time, one of which was much earlier than the other. 
The rocks that are so well shown in the mountain slope on the east 
(right) are supposed to belong to the lower part of the upper Car- 
boniferous or, in other words, to have been formed at the same time 
as the earliest of the great coal beds in the Appalachian region and 
the Mississippi Valley. In the Rocky Mountains some coal beds have 
been found in these rocks, but most of them are too small or too im- 
that marks the other limit of the Cross Creek — 
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