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NINE-LAKE BASIN, AT THE HEAD OF BIG ARROYO

Photo by Walter L. Huber

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SIERRA CLUB BULLETIN, VOL. X.

HEAD OF ROARING RIVER CAÑON

Photo by Walter L. Huber

all our labor. So much snow and rock work and the difficulty of two passes over 12,000 feet each had caused a weariness that induced sleep instantly.

Now, although the downy couch of the city had supplanted the rocky cradle of the wilderness, the poppy-crowned goddess approaches with a greater deliberation. In that interval there sometimes flashes on my mind something seen on that trip to Bearpaw, and especially on Deer Creek. And if I dream, it is not of a great highway from New York to San Francisco, wonderful as that would be, but of a mere trail instead. It runs by way of Deer Creek, and its pilgrims saunter upward from the solemnity of the Giant Forest to the grandeur of the Big Arroyo.

STUDIES IN THE SIERRA*

By John MUIR

NO, III. ANCIENT GLACIERS AND THEIR PATHWAYS

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'HOUGH the gigantic glaciers of the Sierra are dead, their

history is indelibly recorded in characters of rock, mountain, cañon, and forest; and, although other hieroglyphics are being incessantly engraved over these, "line upon line,” the glacial characters are so enormously emphasized that they rise free and unconfused in sublime relief, through every after inscription, whether of the torrent, the avalanche, or the restless heaving atmosphere.

In order to give the reader definite conceptions of the magnitude and aspect of these ancient ice-rivers, I will briefly outline those which were most concerned in the formation of Yosemite Valley and its cañon branches. We have seen (in the previous paper) that Yosemite received the simultaneous thrust of the Yosemite Creek, Hoffmann, Tenaya, South Lyell, and Illilouette glaciers. These welded themselves together into one huge trunk, which swept down through the valley, receiving small affluents in its course from Pohono, Sentinel, and Indian cañons, and those on both sides of El Capitan Rock. At this period most of the upper portions of the walls of the valley were bare; but during its earliest history, the wide mouths of these several glaciers formed an almost uninterrupted covering of ice. All the ancient glaciers of the Sierra fluctuated in depth and width, and in degree of individuality, down to the latest glacial days. It must, therefore, be distinctly borne in mind that the following sketches of these upper Merced glaciers relate only to their separate condition, and to that phase of their separate condition which they presented toward the close of the period when Yosemite and its branches were works nearly accomplished.

* Reprinted from the Overland Monthly of July, 1874. This is the third of a series of seven studies in which Mr. Muir developed his theories of the geology of the Sierra.-Editor.

† Reprinted in SIERRA CLUB BULLETIN, Vol. X, No. 1, January, 1916.

YOSEMITE CREEK GLACIER The broad, many-fountained glacier to which the basin of Yosemite Creek belonged, was about fourteen miles in length by four in width, and in many places was not less than a thousand feet in depth. Its principal tributaries issued from lofty amphitheatres laid well back among the northern spurs of the Hoffmann range. These at first pursued a westerly course; then, uniting with each other and absorbing a series of small affluents from the Tuolumne divide, the trunk thus formed swept round to the south in a magnificent curve, and poured its ice into Yosemite in cascades two miles wide. This broad glacier formed a kind of wrinkled ice-cloud. As it grew older, it became more regular and riverlike; encircling peaks overshadowed its upper fountains, rock islets rose at intervals among its shallowing currents, and its bright sculptured banks, nowhere overflowed, extended in massive simplicity all the way to its mouth. As the ice-winter drew near a close, the main trunk, becoming torpid, at length wholly disappeared in the sun, and a waiting multitude of plants and animals entered the new valley to inhabit the mansions prepared for them. In the meantime the chief tributaries, creeping slowly back into the shelter of their fountain shadows, continued to live and work independently, spreading moraine soil for gardens, scooping basins for lakelets, and leisurely completing the sculpture of their fountains. These also have at last vanished, and the whole basin is now full of light. Forests flourish luxuriantly over all its broad moraines, lakes and meadows nestle among its domes, and a thousand flowery gardens are outspread along its streams.

HOFFMANN GLACIER The short, swift-flowing Hoffmann Glacier offered a striking contrast to the Yosemite Creek, in the energy and directness of its movements, and the general tone and tendencies of its life. The erosive energy of the latter was diffused over a succession of low boulderlike domes. Hoffmann Glacier, on the contrary, moved straight to its mark, making a descent of 5000 feet in about five miles, steadily deepening and contracting its current, and finally thrusting itself against the upper portion of Yosemite in the form of a wedge of solid ice, six miles in length by

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