which the glaciers rose;
while the numerous moraines, curving and swaying in beautiful lines,
mark the boundaries of the main trunk and its tributaries as they
existed toward the close of the glacial winter. None of the commerical
highways of the land or sea, marked with buoys and lamps, fences, and
guide-boards, is so unmistakably indicated as are these broad, shining
trails of the vanished Tuolumne Glacier and its far-reaching
tributaries.

I should like now to offer some nearer views of a few characteristic
specimens of these wonderful old ice-streams, though it is not easy to
make a selection from so vast a system intimately inter-blended. The
main branches of the Merced Glacier are, perhaps, best suited to our
purpose, because their basins, full of telling inscriptions, are the
ones most attractive and accessible to the Yosemite visitors who like to
look beyond the valley walls. They number five, and may well be called
Yosemite glaciers, since they were the agents Nature used in developing
and fashioning the grand Valley. The names I have given them are,
beginning with the northern-most, Yosemite Creek, Hoffman, Tenaya, South
Lyell, and Illilouette Glaciers. These all converged in admirable poise
around from northeast to southeast, welded themselves together into the
main Yosemite Glacier, which, grinding gradually deeper, swept down
through the Valley, receiving small tributaries on its way from the
Indian, Sentinel, and Pohono Canyons; and at length flowed out of the
Valley, and on down the Range in a general westerly direction. At the
time that the tributaries mentioned above were well defined as to their
boundaries, the upper portion of the valley walls, and the highest rocks
about them, such as the Domes, the uppermost of the Three Brothers and
the Sentinel, rose above the surface of the ice. But during the Valley's
earlier history, all its rocks, however lofty, were buried beneath a
continuous sheet, which swept on above and about them like the wind, the
upper portion of the current flowing steadily, while the lower portion
went mazing and swedging down in the crooked and dome-blocked canyons
toward the head of the Valley.

Every glacier of the Sierra fluctuated in width and depth and length,
and consequently in degree of individuality, down to the latest
glacial days. It must, therefore, be borne in mind that the following
description of the Yosemite glaciers applies only to their separate
condition, and t