aying glacier headlands have been
undermined and thrown down in loose taluses, while most of the
moraines and striae and scratches have been blurred or weathered away.
Nevertheless, enough remains of the more recent and the more enduring
phenomena to cast a good light well back upon the conditions of the
ancient ice sheet that covered this interesting region, and upon the
system of distinct glaciers that loaded the tops of the mountains and
filled the canyons long after the ice sheet had been broken up.

The first glacial traces that I noticed in the basin are on the Wassuck,
Augusta, and Toyabe ranges, consisting of ridges and canyons, whose
trends, contours, and general sculpture are in great part specifically
glacial, though deeply blurred by subsequent denudation. These
discoveries were made during the summer of 1876-77. And again, on the
17th of last August, while making the ascent of Mount Jefferson, the
dominating mountain of the Toquima range, I discovered an exceedingly
interesting group of moraines, canyons with V-shaped cross sections,
wide neve amphitheatres, moutoneed rocks, glacier meadows, and one
glacier lake, all as fresh and telling as if the glaciers to which they
belonged had scarcely vanished.

The best preserved and most regular of the moraines are two laterals
about two hundred feet in height and two miles long, extending from the
foot of a magnificent canyon valley on the north side of the mountain
and trending first in a northerly direction, then curving around to the
west, while a well-characterized terminal moraine, formed by the
glacier towards the close of its existence, unites them near their lower
extremities at a height of eighty-five hundred feet. Another pair of
older lateral moraines, belonging to a glacier of which the one just
mentioned was a tributary, extend in a general northwesterly direction
nearly to the level of Big Smoky Valley, about fifty-five hundred feet
above sea level.

Four other canyons, extending down the eastern slopes of this grand old
mountain into Monito Valley, are hardly less rich in glacial records,
while the effects of the mountain shadows in controlling and directing
the movements of the residual glaciers to which all these phenomena
belonged are everywhere delightfully apparent in the trends of the
canyons and ridges, and in the massive sculpture of the neve wombs at
their heads. This is a very marked and imposing mountain, attracting
the eye from a grea