512 ALLEN DAVID HOLE 
18 feet in diameter, and containing representatives of the various 
kinds of rock present in the basins from which the drift was derived, 
(7) striated bowlders included in the unassorted drift, (8) streams 
steep in gradient flowing in valleys U-shaped in cross-section, and 
(9) hanging valleys. Of the evidences named above it was found 
that a part of that referable to classes 5, 6, and 7 represents the 
work of an epoch or epochs of glaciation earlier than the most 
recent. Some of this earlier drift occurs in or near valleys in which 
ice of the latest epoch was present; but some in valleys which 
appear not to have been subject to the action of ice of so recent a 
time. Furthermore, the earlier drift is in some cases found on 
divides between valleys instead of on the slopes or bottom as is 
usually the case with the more recent drift, and in many cases gla- 
ciated valleys contain drift of the most recent epoch only. In view 
of these facts in regard to the distribution of drift of different epochs, 
the detailed descriptions of glacial phenomena in different basins 
and valleys have been grouped as follows: 
I. Phenomena in each valley referred to glacial action of the 
more recent epoch. 
II. Phenomena referred to glacial action distinctly earlier 
in time. 
DESCRIPTION OF AREAS GLACIATED IN THE MORE RECENT EPOCH 
VALLEY OF THE SAN MIGUEL RIVER 
The San Miguel River is formed by the junction of Ingram and 
Bridal Veil creeks about two and one-half miles east of the city of 
Telluride. The walls of the valley near this point are, for much of 
their height, bare precipices, and rise from 2,000 to 3,000 feet above 
the bed of the stream. The channel of Ingram Creek is a con- 
tinuation in direct line of the valley of the San Miguel River; but 
from a point a half a mile above its junction with Bridal Veil Creek 
to the level of the lower part of Ingram Basin, a vertical distance 
of over 1,000 feet, the gradient of the stream is practically that of 
the slope of the walls of the valley of the San Miguel on either side, 
so that the steep side walls of the valley of the San Miguel virtually 
meet each other to the east, forming a cul-de-sac which differs from 
