Snow-Storms
As has been already stated, the first of the great snow-storms that
replenish the Yosemite fountains seldom sets in before the end of
November. Then, warned by the sky, wide-awake mountaineers, together
with the deer and most of the birds, make haste to the lowlands or
foothills; and burrowing marmots, mountain beavers, wood-rats, and
other small mountain people, go into winter quarters, some of them not
again to see the light of day until the general awakening and
resurrection of the spring in June or July. The fertile clouds,
drooping and condensing in brooding silence, seem to be thoughtfully
examining the forests and streams with reference to the work that lies
before them. At length, all their plans perfected, tufted flakes and
single starry crystals come in sight, solemnly swirling and glinting to
their blessed appointed places; and soon the busy throng fills the sky
and makes darkness like night. The first heavy fall is usually from
about two to four feet in depth then with intervals of days or weeks of
bright weather storm succeeds storm, heaping snow on snow, until thirty
to fifty feet has fallen. But on account of its settling and
compacting, and waste from melting and evaporation, the average depth
actually found at any time seldom exceeds ten feet in the forest
regions, or fifteen feet along the slopes of the summit peaks. After
snow-storms come avalanches, varying greatly in form, size, behavior
and in the songs they sing; some on the smooth slopes of the mountains
are short and broad; others long and river-like in the side cañons of
yosemites and in the main cañons, flowing in regular channels and
booming like waterfalls, while countless smaller ones fall everywhere
from laden trees and rocks and lofty cañon walls. Most delightful it is
to stand in the middle of Yosemite on still clear mornings after
snow-storms and watch the throng of avalanches as they come down,
rejoicing, to their places, whispering, thrilling like birds, or
booming and roaring like thunder. The noble yellow pines stand hushed
and motionless as if under a spell until the morning sunshine begins to
sift through their laden spires; then the dense masses on the ends of
the leafy branches begin to shift and fall, those from the upper
branches striking the lower ones in succession, enveloping each tree in
a hollow conical avalanche of fairy fineness; while the relieved
branches spring up and wave with startling effect in the general
stillness, as if each tree was moving of its own volition. Hundreds of
broad cloud-shaped masses may also be seen, leaping over the brows of
the cliffs from great heights, descending at first with regular
avalanche speed until, worn into dust by friction, they float in front
of the precipices like irised clouds. Those which descend from the brow
of El Capitan are particularly fine; but most of the great Yosemite
avalanches flow in regular channels like cascades and waterfalls. When
the snow first gives way on the upper slopes of their basins, a dull
rushing, rumbling sound is heard which rapidly increases and seems to
draw nearer with appalling intensity of tone. Presently the white flood
comes bounding into sight over bosses and sheer places, leaping from
bench to bench, spreading and narrowing and throwing off clouds of
whirling dust like the spray of foaming cataracts. Compared with
waterfalls and cascades, avalanches are short-lived, few of them
lasting more than a minute or two, and the sharp, clashing sounds so
common in falling water are mostly wanting; but in their low massy
thundertones and purple-tinged whiteness, and in their dress, gait,
gestures and general behavior, they are much alike.
Avalanches
Besides these common after-storm avalanches that are to be found not
only in the Yosemite but in all the deep, sheer-walled cañon of the
Range there are two other important kinds, which may be called annual
and century avalanches, which still further enrich the scenery. The
only place about the Valley where one may be sure to see the annual
kind is on the north slope of Clouds’ Rest. They are composed of heavy,
compacted snow, which has been subjected to frequent alternations of
freezing and thawing. They are developed on cañon and mountain-sides at
an elevation of from nine to ten thousand feet, where the slopes are
inclined at an angle too low to shed off the dry winter snow, and which
accumulates until the spring thaws sap their foundations and make them
slippery; then away in grand style go the ponderous icy masses without
any fine snow-dust. Those of Clouds’ Rest descend like thunderbolts for
more than a mile.
The great century avalanches and the kind that mow wide swaths through
the upper forests occur on mountain-sides about ten or twelve thousand
feet high, where under ordinary weather conditions the snow accumulated
from winter to winter lies at rest for many years, allowing trees,
fifty to a hundred feet high, to grow undisturbed on the slopes beneath
them. On their way down through the woods they seldom fail to make a
perfectly clean sweep, stripping off the soil as well as the trees,
clearing paths two or three hundred yards wide from the timber line to
the glacier meadows or lakes, and piling their uprooted trees, head
downward, in rows along the sides of the gaps like lateral moraines.
Scars and broken branches of the trees standing on the sides of the
gaps record the depth of the overwhelming flood; and when we come to
count the annual wood-rings on the uprooted trees we learn that some of
these immense avalanches occur only once in a century or even at still
wider intervals.
A Ride On An Avalanche
Few Yosemite visitors ever see snow avalanches and fewer still know the
exhilaration of riding on them. In all my mountaineering I have enjoyed
only one avalanche ride, and the start was so sudden and the end came
so soon I had but little time to think of the danger that attends this
sort of travel, though at such times one thinks fast. One fine Yosemite
morning after a heavy snowfall, being eager to see as many avalanches
as possible and wide views of the forest and summit peaks in their new
white robes before the sunshine had time to change them, I set out
early to climb by a side cañon to the top of a commanding ridge a
little over three thousand feet above the Valley. On account of the
looseness of the snow that blocked the cañon I knew the climb would
require a long time, some three or four hours as I estimated; but it
proved far more difficult than I had anticipated. Most of the way I
sank waist deep, almost out of sight in some places. After spending the
whole day to within half an hour or so of sundown, I was still several
hundred feet below the summit. Then my hopes were reduced to getting up
in time to see the sunset. But I was not to get summit views of any
sort that day, for deep trampling near the cañon head, where the snow
was strained, started an avalanche, and I was swished down to the foot
of the cañon as if by enchantment. The wallowing ascent had taken
nearly all day, the descent only about a minute. When the avalanche
started I threw myself on my back and spread my arms to try to keep
from sinking. Fortunately, though the grade of the cañon is very steep,
it is not interrupted by precipices large enough to cause outbounding
or free plunging. On no part of the rush was I buried. I was only
moderately imbedded on the surface or at times a little below it, and
covered with a veil of back-streaming dust particles; and as the whole
mass beneath and about me joined in the flight there was no friction,
though I was tossed here and there and lurched from side to side. When
the avalanche swedged and came to rest I found myself on top of the
crumpled pile without bruise or scar. This was a fine experience.
Hawthorne says somewhere that steam has spiritualized travel; though
unspiritual smells, smoke, etc., still attend steam travel. This flight
in what might be called a milky way of snow-stars was the most
spiritual and exhilarating of all the modes of motion I have ever
experienced. Elijah’s flight in a chariot of fire could hardly have
been more gloriously exciting.
The Streams In Other Seasons
In the spring, after all the avalanches are down and the snow is
melting fast, then all the Yosemite streams, from their fountains to
their falls, sing their grandest songs. Countless rills make haste to
the rivers, running and singing soon after sunrise, louder and louder
with increasing volume until sundown; then they gradually fail through
the frosty hours of the night. In this way the volume of the upper
branches of the river is nearly doubled during the day, rising and
falling as regularly as the tides of the sea. Then the Merced overflows
its banks, flooding the meadows, sometimes almost from wall to wall in
some places, beginning to rise towards sundown just when the streams on
the fountains are beginning to diminish, the difference in time of the
daily rise and fall being caused by the distance the upper flood
streams have to travel before reaching the Valley. In the warmest
weather they seem fairly to shout for joy and clash their upleaping
waters together like clapping of hands; racing down the cañons with
white manes flying in glorious exuberance of strength, compelling huge,
sleeping boulders to wake up and join in their dance and song, to swell
their exulting chorus.
In early summer, after the flood season, the Yosemite streams are in
their prime, running crystal clear, deep and full but not overflowing
their banks—about as deep through the night as the day, the difference
in volume so marked in spring being now too slight to be noticed.
Nearly all the weather is cloudless and everything is at its
brightest—lake, river, garden and forest with all their life. Most of
the plants are in full flower. The blessed ouzels have built their
mossy huts and are now singing their best songs with the streams.
In tranquil, mellow autumn, when the year’s work is about done and the
fruits are ripe, birds and seeds out of their nests, and all the
landscape is glowing like a benevolent countenance, then the streams
are at their lowest ebb, with scarce a memory left of their wild spring
floods. The small tributaries that do not reach back to the lasting
snow fountains of the summit peaks shrink to whispering, tinkling
currents. After the snow is gone from the basins, excepting occasional
thundershowers, they are now fed only by small springs whose waters are
mostly evaporated in passing over miles of warm pavements, and in
feeling their way slowly from pool to pool through the midst of
boulders and sand. Even the main rivers are so low they may easily be
forded, and their grand falls and cascades, now gentle and
approachable, have waned to sheets of embroidery.