Part 15

In general outline the geology of the region is simple. Its bounding ranges were chiefly blocked out at the period of Jurassic upheaval, when the Sierra Nevada and Wahsatch Mountains were folded. Masses of upheaved granite, with overlying slates and limestones, form the main materials of the cordon of surrounding hills. During the Cretaceous and Tertiary periods the entire basin, from the Rocky Mountains to the Blue Mountains of Oregon, was a fresh-water lake, on whose bottom was deposited a curious succession of sand and clay beds, including, near the surface, a layer of white, infusorial silica. At the exposures of these rocks in the cañon-walls of the present drainage system are found ample evidences of the kind of life which flourished in the lake itself and lived upon its borders. Savage fishes, of the garpike type, and vast numbers of cyprinoids, together with mollusks, are among the prominent water-fossils. Enough relics of the land vegetation remain to indicate a flora of a sub-tropical climate; and among the land-fossils are numerous bones of elephant, camel, horse, elk, and deer.

The _savant_ to whose tender mercies these _disjecta membra_ have been committed, finds in the molluscan life the most recent types yet discovered in the American Tertiaries,--forms closely allied to existing Asiatic species. How and wherefore this lake dried up, and gave place to the present barren wilderness of sand and sage, is one of those profound conundrums of nature yet unguessed by geologists. From being a wide and beautiful expanse of water, edged by winding mountain-shores, with forest-clad slopes containing a fauna whose remains are now charming those light-minded fellows, the paleontologists, the scene has entirely changed, and a monotonous, blank desert spreads itself as far as the eye can reach. Only here and there, near the snowy mountain-tops, a bit of cool green contrasts refreshingly with the sterile uniformity of the plain. During the period of desiccation, perhaps in a measure accounting for it, a general flood of lava poured down from the mountains and deluged nearly the whole Snake Basin. The chief sources of this lava lay at the eastern edge, where subsequent erosion has failed to level several commanding groups of volcanic peaks. The three buttes and three tetons mark centres of flow. Remarkable features of the volcanic period were the sheets of basaltic lava which closed the eruptive era, and in thin, continuous layers overspread the plain for three hundred miles. The earlier flows extended farthest to the west. The ragged, broken terminations of the later sheets recede successively eastward, in a broad, gradual stairway; so that the present topography of the basin is a gently inclined field of basaltic lava, sinking to the west, and finally, by a series of terraced steps, descending to the level of lacustrine sand-rocks which mark the bottom of the ancient lake, and cover the plain westward into Oregon.

The head-waters of the Snake River, gathering snow-drainage from a considerable portion of the Rocky Mountains, find their way through a series of upland valleys to the eastern margin of the Snake plain, and there gathering in one main stream flow westward, occupying a gradually deepening cañon; a narrow, dark gorge, water-worn through the thin sheets of basalt, cutting down as it proceeds to the westward, until, in longitude 114° 20´, it has worn seven hundred feet into the lava. Several tributaries flowing through similar though less profound cañons join the Snake both north and south. From the days of Lewis, for whom this Snake or Shoshone River was originally named, up to the present day, rumors have been current of cataracts in the Snake cañon. It is curious to observe that all the earlier accounts estimate their height as six hundred feet, which is exactly the figure given by the first Jesuit observers of Niagara. That erratic amateur Indian, Catlin, actually visited these falls; and his account of them, while it entirely fails to give an adequate idea of their formation and grandeur, is nevertheless, in the main, truthful. Since the mining development of Idaho, several parties have visited and examined the Shoshone.

In October, 1868, with a small detachment of the United States Geological Survey of the 40th Parallel, the writer crossed Goose Creek Mountains, in northern Utah, and descended by the old Fort Boise road to the level of the Snake plain. A gray, opaque haze hung close to the ground, and shut out all distance. The monotony of sage-desert was overpowering. We would have given anything for a good outlook; but for three days the mist continued, and we were forced to amuse ourselves by chasing occasional antelopes.

The evening we camped on Rock Creek was signalized by a fierce wind from the northeast. It was a dry storm, which continued with tremendous fury through the night, dying away at daybreak, leaving the heavens brilliantly clear. We were breakfasting when the sun rose, and shortly afterward, mounting into the saddle, headed toward the cañon of the Shoshone. The air was cold and clear. The remotest mountain-peaks upon the horizon could be distinctly seen, and the forlorn details of their brown slopes stared at us as through a vacuum. A few miles in front the smooth surface of the plain was broken by a ragged, zigzag line of black, which marked the edge of the farther wall of the Snake cañon. A dull, throbbing sound greeted us. Its pulsations were deep, and seemed to proceed from the ground beneath our feet.

Leaving the cavalry to bring up the wagon, my two friends and I galloped on, and were quickly upon the edge of the cañon-wall. We looked down into a broad, circular excavation, three quarters of a mile in diameter, and nearly seven hundred feet deep. East and north, over the edges of the cañon, we looked across miles and miles of the Snake plain, far on to the blue boundary mountains. The wall of the gorge opposite us, like the cliff at our feet, sank in perpendicular bluffs nearly to the level of the river, the broad excavation being covered by rough piles of black lava and rounded domes of trachyte rock. We saw an horizon as level as the sea; a circling wall, whose sharp edges were here and there battlemented in huge, fortress-like masses; a broad river, smooth and unruffled, flowing quietly into the middle of the scene, and then plunging into a labyrinth of rocks, tumbling over a precipice two hundred feet high, and moving westward in a still, deep current, to disappear behind a black promontory. It was a strange, savage scene: a monotony of pale blue sky, olive and gray stretches of desert, frowning walls of jetty lava, deep beryl-green of river-stretches, reflecting, here and there, the intense solemnity of the cliffs, and in the centre a dazzling sheet of foam. In the early morning light the shadows of the cliffs were cast over half the basin, defining themselves in sharp outline here and there on the river. Upon the foam of the cataract one point of the rock cast a cobalt-blue shadow. Where the river flowed round the western promontory, it was wholly in shadow, and of a deep sea-green. A scanty growth of coniferous trees fringed the brink of the lower cliffs, overhanging the river. Dead barrenness is the whole sentiment of the scene. The mere suggestion of trees clinging here and there along the walls serves rather to heighten than to relieve the forbidding gloom of the place. Nor does the flashing whiteness, where the river tears itself among the rocky islands, or rolls in spray down the cliff, brighten the aspect. In contrast with its brilliancy, the rocks seem darker and more wild.

The descent of four hundred feet from our standpoint to the level of the river above the falls has to be made by a narrow, winding path, among rough ledges of lava. We were obliged to leave our wagon at the summit, and pack down the camp equipment and photographic apparatus upon carefully led mules. By midday we were comfortably camped on the margin of the left bank, just above the brink of the falls. My tent was pitched upon the edge of a cliff, directly overhanging the rapids. From my door I looked over the cataract, and, whenever the veil of mist was blown aside, could see for a mile down the river. The lower half of the cañon is excavated in a gray, porphyritic trachyte. It is over this material that the Snake falls. Above the brink the whole breadth of the river is broken by a dozen small trachyte islands, which the water has carved into fantastic forms, rounding some into low domes, sharpening others into mere pillars, and now and then wearing out deep caves. At the very brink of the fall a few twisted evergreens cling with their roots to the rock, and lean over the abyss of foam with something of that air of fatal fascination which is apt to take possession of men.

In plan the fall recurves up stream in a deep horseshoe, resembling the outline of Niagara. The total breadth is about seven hundred feet, and the greatest height of the single fall about one hundred and ninety. Among the islands above the brink are several beautiful cascades, where portions of the river pour over in lace-like forms. The whole mass of cataract is one ever-varying sheet of spray. In the early spring, when swollen by the rapidly melted snows, the river pours over with something like the grand volume of Niagara, but at the time of my visit it was wholly white foam. Here and there along the brink the underlying rock shows through, and among the islands shallow, green pools disclose the form of the underlying trachyte. Numberless rough shelves break the fall, but the volume is so great that they are only discovered by the glancing outward of the foam.

The river below the falls is very deep. The right bank sinks into the water in a clear, sharp precipice, but on the left side a narrow, pebbly beach extends along the foot of the cliff. From the top of the wall, at a point a quarter of a mile below the falls, a stream has gradually worn a little stairway: thick growths of evergreens have huddled together in this ravine.

By careful climbing we descended to the level of the river. The trachytes are very curiously worn in vertical forms. Here and there an obelisk, either wholly or half detached from the cañon-wall, juts out like a buttress. Farther down, these projecting masses stand like a row of columns upon the left bank. Above them, a solid capping of black lava reaches out to the edge, and overhangs the river in abrupt, black precipices. Wherever large fields of basalt have overflowed an earlier rock, and erosion has afterward laid it bare, there is found a strong tendency to fracture in vertical lines. The immense expansion of the upper surface from heat seems to cause deep fissures in the mass.

Under the influence of the cool shadow of cliffs and pine, and constant percolating of surface-waters, a rare fertility is developed in the ravines opening upon the cañon shore. A luxuriance of ferns and mosses, an almost tropical wealth of green leaves and velvety carpeting, line the banks. There are no rocks at the base of the fall. The sheet of foam plunges almost vertically into a dark, beryl-green, lake-like expanse of the river. Immense volumes of foam roll up from the cataract-base, and, whirling about in the eddying winds, rise often a thousand feet in the air. When the wind blows down the cañon a gray mist obscures the river for half a mile; and when, as is usually the case in the afternoon, the breezes blow eastward, the foam-cloud curls over the brink of the fall, and hangs like a veil over the upper river. On what conditions depends the height to which the foam-cloud rises from the base of the fall it is apparently impossible to determine. Without the slightest wind, the cloud of spray often rises several hundred feet above the cañon-wall, and again, with apparently the same conditions of river and atmosphere, it hardly reaches the brink. Incessant roar, reinforced by a thousand echoes, fills the cañon. Out of this monotone, from time to time, rise strange, wild sounds, and now and then may be heard a slow, measured beat, not unlike the recurring fall of breakers. From the white front of the cataract the eye constantly wanders up to the black, frowning parapet of lava. Angular bastions rise sharply from the general level of the wall, and here and there isolated blocks, profiling upon their sky line, strikingly recall barbette batteries. To goad one’s imagination up to the point of perpetually seeing resemblances of everything else in the forms of rocks is the most vulgar vice of travellers. To refuse to see the architectural suggestions upon the Snake cañon, however, is to administer a flat snub to one’s fancy. The whole edge of the cañon is deeply cleft in vertical crevasses. The actual brink is usually formed of irregular blocks and prisms of lava, poised upon their ends in an unstable equilibrium, ready to be tumbled over at the first leverage of the frost. Hardly an hour passes without the sudden boom of one of those rock-masses falling upon the ragged _débris_ piles below.

Night is the true time to appreciate the full force of the scene. I lay and watched it many hours. The broken rim of the basin profiled itself upon a mass of drifting clouds where torn openings revealed gleams of pale moonlight and bits of remote sky trembling with misty stars. Intervals of light and blank darkness hurriedly followed each other. For a moment the black gorge would be crowded with forms. Tall cliffs, ramparts of lava, the rugged outlines of islands huddled together on the cataract’s brink, faintly luminous foam breaking over black rapids, the swift, white leap of the river, and a ghostly, formless mist through which the cañon-walls and far reach of the lower river were veiled and unveiled again and again. A moment of this strange picture, and then a rush of black shadow, when nothing could be seen but the breaks in the clouds, the basin-rim, and a vague, white centre in the general darkness.

After sleeping on the nightmarish brink of the falls, it was no small satisfaction to climb out of this Dantean gulf and find myself once more upon a pleasantly prosaic foreground of sage. Nothing more effectually banishes a melotragic state of the mind than the obtrusive ugliness and abominable smell of this plant. From my feet a hundred miles of it stretched eastward. A half-hour’s walk took me out of sight of the cañon, and as the wind blew westward, only occasional indistinct pulsations of the fall could be heard. The sky was bright and cloudless, and arched in cheerful vacancy over the meaningless disk of the desert.

I walked for an hour, following an old Indian trail which occasionally approached within seeing distance of the river, and then, apparently quite satisfied, diverged again into the desert. When about four miles from the Shoshone, it bent abruptly to the north, and led to the cañon edge. Here again the narrow gorge widened into a broad theatre, surrounded, as before, by black, vertical walls, and crowded over its whole surface by rude piles and ridges of volcanic rock. The river entered it from the east through a magnificent gateway of basalt, and, having reached the middle, flowed on either side of a low, rocky island, and plunged in two falls into a deep green basin. A very singular ridge of the basalt projected like an arm almost across the river, enclosing within its semi-circle a bowl three hundred feet in diameter and two hundred feet deep. Within this the water was of the same peculiar beryl-green, dappled here and there by masses of foam which swam around and around with a spiral tendency toward the centre. To the left of the island half the river plunged off an overhanging lip, and fell about one hundred and fifty feet, the whole volume reaching the surface of the basin many feet from the wall. The other half has worn away the edge, and descends in a tumbling cascade at an angle of about forty-five degrees. The river at this point has not yet worn through the fields of basaltic lava which form the upper four hundred feet of the plain. Between the two falls it cuts through the remaining beds of basalt, and has eroded its channel a hundred feet into underlying porphyritic trachyte. The trachyte erodes far more easily than the basalt, and its resultant forms are quite unlike those of the black lava. The trachyte islands and walls are excavated here and there in deep caves, leaving island masses in the forms of mounds and towers. In general, spherical outlines predominate, while the erosion of the basalt results always in sharp, perpendicular cliffs, with a steeply inclined talus of ragged _débris_.

The cliffs around the upper cataract are inferior to those of the Shoshone. While the level of the upper plain remains nearly the same, the river constantly deepens the channel in its westward course. In returning from the upper fall, I attempted to climb along the very edge of the cliff, in order to study carefully the habits of the basalt; but I found myself in a labyrinth of side crevasses which were cut into the plain from a hundred to a thousand feet back from the main wall. These recesses were usually in the form of an amphitheatre, with black walls two hundred feet high, and a bottom filled with immense fragments of basalt rudely piled together.

By dint of hard climbing I reached the actual brink in a few places, and saw the same general features each time: the cañon successively widening and narrowing, its walls here and there approaching each other and standing like pillars of a gateway; the river alternately flowing along smooth, placid reaches of level, and rushing swiftly down rocky cascades. Here and there along the cliff are disclosed mouths of black caverns, where the lava seems to have been blown up in the form of a great blister, as if the original flow had poured over some pool of water, and, converted into steam by contact with the hot rock, had been blown up bubble-like by its immense expansion.

I continued my excursions along the cañon west of the Shoshone. About a mile below the fall a very fine promontory juts sharply out and projects nearly to the middle of the cañon. Climbing with difficulty along its toppling crest, I reached a point which I found composed of immense, angular fragments piled up in dangerous poise. Eastward, the battlemented rocks around the falls limited the view; but westward I could see down long reaches of river, where islands of trachyte rose above white cascades. A peculiar and fine effect is noticeable upon the river during all the midday. The shadow of the southern cliff is cast down here and there, completely darkening the river, but often defining itself upon the water. The contrast between the rich, gem-like green of the sunlit portions and the deep violet shadow of the cliff is of extreme beauty. The Snake River, deriving its volume wholly from the melting of the mountain snows, is a direct gauge of the annual advance of the sun. In June and July it is a tremendous torrent, carrying a full half of the Columbia. From the middle of July it constantly shrinks, reaching its minimum in midwinter. At the lowest, it is a river equal to the Sacramento or Connecticut.

After ten days devoted to walking around the neighborhood and studying the falls and rocks, we climbed to our wagon, and rested for a farewell look at the gorge. It was with great relief that we breathed the free air of the plain, and turned from the rocky cañon where darkness, and roar, and perpetual cliffs had bounded our senses, and headed southward, across the noiseless plain. Far ahead rose a lofty, blue barrier, a mountain-wall, marbled upon its summit by flecks of perpetual snow. A deep notch in its profile opened a gateway. Toward this, for leagues ahead of us, a white thread in the gray desert marked the winding of our road. Those sensitively organized creatures, the mules, thrilled with relief at their escape from the cañons, pressed forward with a vigor that utterly silenced the customary poppings of the whip, and expurgated the language of the driver from his usual breaking of the Third Commandment.

The three great falls of America--Niagara, Shoshone, and Yosemite--all, happily, bearing Indian names, are as characteristically different as possible. There seems little left for a cataract to express.

Niagara rolls forward with something like the inexorable sway of a natural law. It is force, power; forever banishing before its irresistible rush all ideas of restraint.

No sheltering pine or mountain distance of up-piled Sierras guards the approach to the Shoshone. You ride upon a waste,--the pale earth stretched in desolation. Suddenly you stand upon a brink, as if the earth had yawned. Black walls flank the abyss. Deep in the bed a great river fights its way through labyrinths of blackened ruins, and plunges in foaming whiteness over a cliff of lava. You turn from the brink as from a frightful glimpse of the Inferno, and when you have gone a mile the earth seems to have closed again; every trace of cañon has vanished, and the stillness of the desert reigns.

As you stand at the base of those cool walls of granite that rise to the clouds from the green floor of Yosemite, a beautiful park, carpeted with verdure, expands from your feet. Vast and stately pines band with their shadows the sunny reaches of the pure Merced. An arch of blue bridges over from cliff to cliff. From the far summit of a wall of pearly granite, over stains of purple and yellow,--leaping, as it were, from the very cloud,--falls a silver scarf, light, lace-like, graceful, luminous, swayed by the wind. The cliffs’ repose is undisturbed by the silvery fall, whose endlessly varying forms of wind-tossed spray lend an element of life to what would otherwise be masses of inanimate stone. The Yosemite is a grace. It is an adornment. It is a ray of light on the solid front of the precipice.

From Yosemite our course was bent toward the Merced Obelisk. An afternoon in early July brought us to camp in the self-same spot where Cotter and I had bivouacked in the storm more than two years before. I remembered the crash and wail of those two dreary nights, the thunderous fulness of tempest beating upon cliffs, and the stealthy, silent snow-burial; and perhaps to the memory of that bitter experience was added the contrasting force of to-day’s beauty.

A warm afternoon sun poured through cloudless skies into one rocky amphitheatre. The little alpine meadow and full, arrowy brook were flanked upon either side by broad, rounded masses of granite, and margined by groups of vigorous upland trees: firs for the most part, but watched over here and there by towering pines and great, aged junipers whose massive red trunks seemed welded to the very stone.

It was altogether exhilarating; even Little Billy, the gray horse, found it so, and devoted more time to practical jokes upon thick-headed mules than to the rich and tempting verdure; nor did the high, cool air banish from his tender heart a glowing Platonic affection for our brown mare Sally.

To the ripened charms of middle age Sally united something more than the memory of youth; she was remarkably plump and well-preserved; her figure firm and elastic, and she did not hesitate to display it with many little arts. In presence of her favored Billy she drew deep sighs, and had quite an irresistible fashion of turning sadly aside and moving away among trees alone, as if she had no one to love her--a wile never failing to bring him to her side and elicit such attention as smoothing her mane or even a pressure of lips upon her brow. And woe to the emotional mule who ventured to cross our little meadow just to feel for a moment the soft comfort of her presence. With the bitterness of a rejected suit he always bore away shoe-prints of jealous Billy.