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Yosemite Trails (1911) by J. Smeaton Chase


CHAPTER II
THE PRINCIPAL ROCK-FEATURES OF THE VALLEY

When one looks down into the Yosemite from a comprehensive vantage-ground such as Inspiration Point, it is seen that the cross-section shape of the valley is somewhat like the letter U. The walls are in general effect vertical; the floor is smooth, level, and as a whole narrow relatively to the height of the walls, sweeping up at the sides to meet them in a natural curve formed by the débris of the cliffs.

This débris is irregularly disposed, there being in some places vast accumulations and in others surprisingly little of the rock-wastage. Although enormous in total amount it is yet so little in view of the great height of the walls that have contributed it that its scantiness is regarded by geologists as remarkable. An average cross-section drawing of the valley would show the débris-angle as a mere trace, hardly easing the abruptness of the sheer plunge of the cliffs to the level of the floor. The greater part of the wreckage is supposed to have fallen in some momentous earthquake that occurred not less than three hundred years ago, the period being determined by the age of trees at present growing upon the talus-slope. Evidences of the cataclysm are strewn thickly all up and down the cañon of the Merced River, which owes much of its picturesque character to the huge obstructions over and between which the rapid stream pours and pushes its way in mile upon mile of foaming cascades. The additions made during later centuries are so trifling in comparison as to be hardly distinguishable, though the slow, steadfast processes of wind and rain, heat and frost, topple down every year many tons of freshly shattered granite to add to the grey and lichened masses that stretch far out across the valley floor.

At intervals along the face of the walls the time-darkened rock is seen to be scarred to its original color, and has very much the appearance of being whitened by frost. These scars mark the paths of rock-slides of recent years. To witness one such avalanche stimulates the spectator to a vivid impression of the majestic uproar involved in Nature’s greater coups de main, such as that must have been which, perhaps at one blow, flung almost the whole of this incalculable weight of rock down into the gulf.

Standing one day of late autumn about the middle of the valley, I was startled by a report like a cannon-shot, which filled the whole valley with echoes that roared and boomed, replied and multiplied, in a long-continued, glorious tumult. As the deafening sound died away in sullen mutterings under the vizor of El Capitan, I was able to distinguish the point of attack by the long, clattering descent of a vast quantity of rock. The night had ‘been a cold one in the valley, while on the seven to eight thousand foot levels of the upper rim the temperature must have dropped almost to zero. Frost, working quietly with his Archimedean lever, had just succeeded in shifting from the shoulder of The Sentinel a trifle of fifty tons or so of granite. For near a thousand feet the boulder fell sheer, swift and silent; then striking the cliff it burst Iike a bomb, shattering into a myriad flying shards and splinters, and dislodging a smother of fragments that trickled down to the valley in a stream that lasted for minutes. Then, from the spot where the boulder had struck, dust began to rise into the sunny air, slowly building up and burgeoning like a summer cloud, and every whit as snowy. It was the flour of granite, powdered instantaneously by the terrific shock.

As I gazed, I reflected upon the spectacular features of the catastrophe which we have seen discussed in magazines as a physical possibility,—the collision of our planet with another stellar body. This proved soon to be too serious a matter for my unscientific mind to contemplate calmly, and it was a relief to turn to the past, and admire the simple rlheetiveness of the device employed by men besieged in castles and walled cities, who rolled down rocks awl other objects of useful specific gravity upon the heads of the obstinate persons who were coming upstairs on scaling-ladders.

The southern wall is noticeably darker in its general color than the northern, probably for the reason that the greater degree of shade encourages a stronger growth of mosses and lichens, both which flourish extravagantly in many places. On the great boulders near the foot of the little Sentinel Fall, thick sheets of moss hang like mantles, embroidered with disks of lichen and distilling slow diamonds from their ragged edges. This side of the walls shows also more of those avalanche-tracks of which I have spoken, and more of the rock-flour of recent manufacture, which, it occurred to me, might well provide the bread of that race of earth-giants whom one may imagine as inhabiting some spacious hall under the arched roof of El Capitan.

I do not know of any place where the tranquil beauty of shadow can be so well seen and felt and studied as in this deep, serene valley. On this unlimited canvas light paints with a mighty brush, in broad half-miles of cobalt and purple and gold and grey. There is continual variety in noting the day-long, quiet changes; continual variety and continual discovery. One may have studied El Capitan and The Sentinel and Half-Dome a score of times, and think that one knows them through and through and yard by yard; but the next observation will show some clouding of color or massing of shadow that quite alters your conception. Even the solid outlines seem to change, and a slant of sunlight or skein of mist will upset the most fixed topographical conclusions. Details even of great extent may easily be overlooked on these huge walls, and such are apt to Ice suddenly projected into visibility by some chance arrangement of light and shade. For instance, I thus became aware of a vast concavity in the face of i;i Capitan which I had never suspected, and which was revealed by a particular obliquity of early morning light in a deep, shell-like bowl of shadow. The Three Brothers, again, seen from the southwest soon after sunrise, show magnificent tone effects, light and shadow being regularly laid in broad, alternate bands of such massiveness and strength as to give a new characteristic to this, as I feel, somewhat formal and uninteresting group.

The Sentinel, that perpendicular elliptical column which stands about midway of the southern wall, is perhaps the least variable in expression of all the notable cliffs of the valley, standing resolutely muffled In shadows until the sun begins to sink to its eclipse behind the high promontory of El Capitan. Then his face glitters with fine Plutonian lines, hard and grim an steel on iron. To me this superb obelisk is, next to the Half-Dome and El Capitan, the dominant point of the valley; and when I have lain awake at night with that tall grey spectre impending over me and obscuring a tenth of the host of heaven, I have been an Egyptian in Thebes, an Assyrian in Nineveh, a Martian or Saturnian for all I knew, under the spell of his solemn enchantment.

At such times, also, I have tried to imagine what would he the sensations of a person who should be transported unawares to this valley, and set down at night among these dimly seen shapes of rock and water. It would be all the better if it happened to be one of those moonlit but partly cloudy nights, when the light comes and goes here and there in sudden gleams and fadings. Here he would see, or doubt whether he saw, close beside and crowding against him, this perpendicular wall, which his eye would follow up and up, until he wondered where the top might be. Over there would be some incomprehensible shape which must surely be a delusion of his own senses. Yonder where the pale column of Yosemite Fall glimmered in the peering light, he would see what might be the straight ascending camp-fire smoke of the departed Indian genius of the place, or perhaps the reek of some weird sacrifice. The falling waters filling the valley with hollow voices and echoes would confuse instead of enlightening him, and the subtle forest-sounds, intricate and perplexing even by day, would add a thousand small mysteries to his bewilderment.

What El Capitan is to the western end of the valley, Half-Dome is to the eastern. And more, for it is, I think, incomparably the most wonderful, striking, and impressive feature of the region. In strangeness of shape this hemispherical mountain of solid granite is singular among the world’s geological marvels, and its sublime height and firm, soaring outline impose it upon the imagination more than would be possible to bulk alone. Professor Whitney in his “Report of the Geological Survey of California,” remarks that “it

THE SENTINEL
[click to enlarge]
THE SENTINEL
strikes even the most casual observer as a new revelation in mountain forms; its existence would be considered an impossibility if it were not there before us in all its reality; it is an unique thing in mountain scenery, and nothing even approaching it can be found except in the Sierra Nevada itself.”

From every part of the upper half of the valley, the eye is compelled as if by the force of physical attraction to return to this extraordinary mountain, which one can never tire of contemplating. One looks upon it almost as one would gaze at some majestic fragment of statuary; and I sometimes wondered with what beautiful phantoms these cloudy domes, pearly cataracts, amethystine gulfs, and sylvan depths of forest would have been peopled if Yosemite had fallen to ancient Greece. For even the matter-of-fact modern mind, surrounded by forms so unusual and heights so solemn, tends to unwarrantable flights of imagination; and one is apt to find one’s self pondering why, as much as how, they were brought into being.

The Half-Dome possesses one feature in particular that I always found remarkable and charming, — the strange manner in which it catches and holds the last light of the day. Often for a full hour after the valley has sunk into shadow, this high Alp, overlooking by two thousand feet the intervening heights, receives the western glow, and like a great heliograph reflects the peaceful messages of the evening over all the quiet valley.

The most eccentric of all the rock-shapes is the double-pinnacled tower called Cathedral Spires, which forms a part of the southern wall near the western end of the valley, and rises, a sheer monolith, to a height of twenty-six hundred feet above the floor level. It is not often that one meets with any really cogent resemblance between Nature’s large, artless architecture and man’s self-conscious handiwork, but in this case the coincidence is quite sufficiently striking to warrant the name (although in my opinion the naming of natural objects with regard to such resemblances is always a reprehensible practice). Old inhabitants recall that the rock originally terminated in three pinnacles, but one of them fell decades ago from its high estate, and only a whitish scar close beside the bases of the remaining two marks the spot where it stood. There is, so far as I am aware, no representation extant of the appearance of this third turret, which must have fallen prior to the year 1864, under which date King refers to “the two sharp, slender minarets of granite”; but if it was at all conformable to its companion spires the peculiarity of the circumstance would be greatly enhanced.

In the little oak-shaded cemetery under Yosemite Point, where the fathers of the valley are sleeping, a fragment of this rock marks the grave of James C. Lamon, who died in the year 1875, and whose name still clings to the orchard which he planted near the junction of the Tenaya Creek with the river. His friend John Conway, who, one of the last of the old backwoodsmen of the region, still lives in the Chowchilla country, a few miles to the south, with fine imagination chose this fallen sky-steeple from which to hew the simple monument of “the pioneer settler of Yosemite.” Not many of us can hope for a memorial as impressive and dignified.

A notable object of this end of the valley is the great castle-like pile which stands just to the west of the Cathedral Spires and is known as Cathedral Rocks. Here again a particular condition of light is needed to give the mass its true power of outline. I used to find this an unimpressive agglomeration of shapeless humps, offering an almost irritating contrast to the powerful lines of El Capitan on the opposite side of the valley, and only imposing by a certain doggedness of contour. But under a late afternoon sun I have seen the group draw into coherence, and reveal a stateliness and quietude of proportion that I was careful, whenever I passed them afterwards, to remember.

The dome-shaped formation which is the marked geological feature of the region, and which is seen on a vast scale in every view of the upper plateau, is perfectly illustrated at one point along the valley wall, where North Dome stands above the salient angle of the Washington Column. It is a conspicuous object from nearly all positions, facing the Half— Dome across the gulf of the Tenaya Cañon; a polished helmet of granite, rising in a pure curve from a cliff that plunges directly to the valley floor. The south and west inclines of the curve are marked by deep fractures which reveal clearly the concentric laminations of the structure.

Of these laminations, Professor Whitney says that “the curves are arranged strictly with reference to the surface of the masses of rock, showing clearly that they must have been produced by the contraction of the material while cooling or solidifying, and also giving very strongly the impression that, in many places, we see something of the original shape of the surface, as it was when the granitic mass assumed its present position.” It is well to bear this in mind, for one is tempted to refer these flowing, convex outlines to glacial action, the traces of which, being so evident throughout the Yosemite region, may easily betray the judgment of the layman. It is natural to the unlearned to conclude that the phenomenon of the domes, accompanied as it is everywhere by striking evidences of glacial denudation, indicates the modelling of the ordinary rugged shapes of mountains by this agency; especially in view of the fact that no example of the dome appears among the highest peaks, whence the glaciers proceeded, and further, that glacial action is clearly shown on many of the domes up to their very summits.

I have not found in the notes of geologists who have surveyed this region any explanation of the peculiar structure, nor any definite statement as to the depth to which the shell-like formation extends. Mr. King indeed observes, referring particularly to El Capitan, that the structure appears to be superficial, never descending more than a hundred feet; but in the case of the Royal Arches, where the vaulting is most remarkable, it is seen at a much greater depth; and this insignificant fractures which occur everywhere on the walls but are too small to be noticed except as one passes close to them in climbing the trails to the upper levels, appear to indicate in a multitude of Instances the same general construction.

It is one more anomaly of the Half-Dome that the two-thousand-foot vertical precipice of the northern face shows no trace of the concentric stratification beyond the thin, overhanging lip at the brink, although its exterior sculpture strongly illustrates the formation.

The imagination finds a fascinating exercise in trying to reconstruct the appearance of the valley during its glacial period. There is evidence that the glad r which occupied it was at one time not less than It thousand feet in depth. From the three main cañons, the Tenaya, the Merced, and the Illilouette, tribuutary glaciers converged, crowding with resistless, elemental movement into the box-like enclosure, surging tip in medial and lateral ridges, and broken by profound crevasses as the ice-river swept around the compressing angles and buttresses of the walls. It would be a stormy lake of ice, its surface ever rearing tip into a new confusion of monstrous shapes; and over the surrounding cliffs ever and anon icy blocks and masses would fall crashing from the brinks, filling the sullen arctic air with solemn uproar.

Traces of the successive terminal moraines of the glacier are still visible to the geologic eye at several points of the valley floor. These moraines probably operated as dams, holding back the water that issued from the retreating glacier and forming the lake which eventually replaced it. This in turn gave place to a meadow formed by the deposit of sediment; and with the arrival of heavier vegetation there ensued at length the present epoch of the valley.

If the future is to continue the revolutions of the past, this loveliest of valleys may still be destined to be the battle-ground of geologic forces; and perhaps it is only our stiffness of imagination that persuades us that the captains will not be as heroic as those of old.

THE HALF-DOME
[click to enlarge]
THE HALF-DOME


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