Part 4 (1/2)

But the vegetation of the pa.s.s has been in great part destroyed, and the same may be said of all the more accessible pa.s.ses throughout the range.

Immense numbers of starving sheep and cattle have been driven through them into Nevada, trampling the wild gardens and meadows almost out of existence. The lofty walls are untouched by any foot, and the falls sing on unchanged; but the sight of crushed flowers and stripped, bitten bushes goes far toward destroying the charm of wildness.

The canon should be seen in winter. A good, strong traveler, who knows the way and the weather, might easily make a safe excursion through it from Yosemite Valley on snow-shoes during some tranquil time, when the storms are hushed. The lakes and falls would be buried then; but so, also, would be the traces of destructive feet, while the views of the mountains in their winter garb, and the ride at lightning speed down the pa.s.s between the snowy walls, would be truly glorious.

[Ill.u.s.tration: VIEW OF THE MONO PLAIN FROM THE FOOT OF b.l.o.o.d.y CAnON.]

CHAPTER VI

THE GLACIER LAKES

Among the many unlooked-for treasures that are bound up and hidden away in the depths of Sierra solitudes, none more surely charm and surprise all kinds of travelers than the glacier lakes. The forests and the glaciers and the snowy fountains of the streams advertise their wealth in a more or less telling manner even in the distance, but nothing is seen of the lakes until we have climbed above them. All the upper branches of the rivers are fairly laden with lakes, like orchard trees with fruit. They lie embosomed in the deep woods, down in the grovy bottoms of canons, high on bald tablelands, and around the feet of the icy peaks, mirroring back their wild beauty over and over again. Some conception of their lavish abundance may be made from the fact that, from one standpoint on the summit of Red Mountain, a day's journey to the east of Yosemite Valley, no fewer than forty-two are displayed within a radius of ten miles. The whole number in the Sierra can hardly be less than fifteen hundred, not counting the smaller pools and tarns, which are innumerable. Perhaps two thirds or more lie on the western flank of the range, and all are restricted to the alpine and subalpine regions. At the close of the last glacial period, the middle and foot-hill regions also abounded in lakes, all of which have long since vanished as completely as the magnificent ancient glaciers that brought them into existence.

Though the eastern flank of the range is excessively steep, we find lakes pretty regularly distributed throughout even the most precipitous portions. They are mostly found in the upper branches of the canons, and in the glacial amphitheaters around the peaks.

Occasionally long, narrow specimens occur upon the steep sides of dividing ridges, their basins swung lengthwise like hammocks, and very rarely one is found lying so exactly on the summit of the range at the head of some pa.s.s that its waters are discharged down both flanks when the snow is melting fast. But, however situated, they soon cease to form surprises to the studious mountaineer; for, like all the love-work of Nature, they are harmoniously related to one another, and to all the other features of the mountains. It is easy, therefore, to find the bright lake-eyes in the roughest and most ungovernable-looking topography of any landscape countenance. Even in the lower regions, where they have been closed for many a century, their rocky orbits are still discernible, filled in with the detritus of flood and avalanche. A beautiful system of grouping in correspondence with the glacial fountains is soon perceived; also their extension in the direction of the trends of the ancient glaciers; and in general their dependence as to form, size, and position upon the character of the rocks in which their basins have been eroded, and the quant.i.ty and direction of application of the glacial force expended upon each basin.

In the upper canons we usually find them in pretty regular succession, strung together like beads on the bright ribbons of their feeding-streams, which pour, white and gray with foam and spray, from one to the other, their perfect mirror stillness making impressive contrasts with the grand blare and glare of the connecting cataracts. In Lake Hollow, on the north side of the Hoffman spur, immediately above the great Tuolumne canon, there are ten lovely lakelets lying near together in one general hollow, like eggs in a nest. Seen from above, in a general view, feathered with Hemlock Spruce, and fringed with sedge, they seem to me the most singularly beautiful and interestingly located lake-cl.u.s.ter I have ever yet discovered.

Lake Tahoe, 22 miles long by about 10 wide, and from 500 to over 1600 feet in depth, is the largest of all the Sierra lakes. It lies just beyond the northern limit of the higher portion of the range between the main axis and a spur that puts out on the east side from near the head of the Carson River. Its forested sh.o.r.es go curving in and out around many an emerald bay and pine-crowned promontory, and its waters are everywhere as keenly pure as any to be found among the highest mountains.

Donner Lake, rendered memorable by the terrible fate of the Donner party, is about three miles long, and lies about ten miles to the north of Tahoe, at the head of one of the tributaries of the Truckee. A few miles farther north lies Lake Independence, about the same size as Donner. But far the greater number of the lakes lie much higher and are quite small, few of them exceeding a mile in length, most of them less than half a mile.

Along the lower edge of the lake-belt, the smallest have disappeared by the filling-in of their basins, leaving only those of considerable size.

But all along the upper freshly glaciated margin of the lake-bearing zone, every hollow, however small, lying within reach of any portion of the close network of streams, contains a bright, br.i.m.m.i.n.g pool; so that the landscape viewed from the mountain-tops seems to be sown broadcast with them. Many of the larger lakes are encircled with smaller ones like central gems girdled with sparkling brilliants. In general, however, there is no marked dividing line as to size. In order, therefore, to prevent confusion, I would state here that in giving numbers, I include none less than 500 yards in circ.u.mference.

In the basin of the Merced River, I counted 131, of which 111 are upon the tributaries that fall so grandly into Yosemite Valley. Pohono Creek, which forms the fall of that name, takes its rise in a beautiful lake, lying beneath the shadow of a lofty granite spur that puts out from Buena Vista peak. This is now the only lake left in the whole Pohono Basin. The Illilouette has sixteen, the Nevada no fewer than sixty-seven, the Tenaya eight, Hoffmann Creek five, and Yosemite Creek fourteen. There are but two other lake-bearing affluents of the Merced, viz., the South Fork with fifteen, and Cascade Creek with five, both of which unite with the main trunk below Yosemite.

[Ill.u.s.tration: LAKE TENAYA, ONE OF THE YOSEMITE FOUNTAINS.]

The Merced River, as a whole, is remarkably like an elm-tree, and it requires but little effort on the part of the imagination to picture it standing upright, with all its lakes hanging upon its spreading branches, the topmost eighty miles in height. Now add all the other lake-bearing rivers of the Sierra, each in its place, and you will have a truly glorious spectacle,--an avenue the length and width of the range; the long, slender, gray shafts of the main trunks, the milky way of arching branches, and the silvery lakes, all clearly defined and s.h.i.+ning on the sky. How excitedly such an addition to the scenery would be gazed at! Yet these lakeful rivers are still more excitingly beautiful and impressive in their natural positions to those who have the eyes to see them as they lie imbedded in their meadows and forests and glacier-sculptured rocks.

When a mountain lake is born,--when, like a young eye, it first opens to the light,--it is an irregular, expressionless crescent, inclosed in banks of rock and ice,--bare, glaciated rock on the lower side, the rugged snout of a glacier on the upper. In this condition it remains for many a year, until at length, toward the end of some auspicious cl.u.s.ter of seasons, the glacier recedes beyond the upper margin of the basin, leaving it open from sh.o.r.e to sh.o.r.e for the first time, thousands of years after its conception beneath the glacier that excavated its basin.

The landscape, cold and bare, is reflected in its pure depths; the winds ruffle its gla.s.sy surface, and the sun fills it with throbbing spangles, while its waves begin to lap and murmur around its leafless sh.o.r.es,--sun-spangles during the day and reflected stars at night its only flowers, the winds and the snow its only visitors. Meanwhile, the glacier continues to recede, and numerous rills, still younger than the lake itself, bring down glacier-mud, sand-grains, and pebbles, giving rise to margin-rings and plats of soil. To these fresh soil-beds come many a waiting plant. First, a hardy carex with arching leaves and a spike of brown flowers; then, as the seasons grow warmer, and the soil-beds deeper and wider, other sedges take their appointed places, and these are joined by blue gentians, daisies, dodecatheons, violets, honeyworts, and many a lowly moss. Shrubs also hasten in time to the new gardens,--kalmia with its glossy leaves and purple flowers, the arctic willow, making soft woven carpets, together with the heathy bryanthus and ca.s.siope, the fairest and dearest of them all. Insects now enrich the air, frogs pipe cheerily in the shallows, soon followed by the ouzel, which is the first bird to visit a glacier lake, as the sedge is the first of plants.

So the young lake grows in beauty, becoming more and more humanly lovable from century to century. Groves of aspen spring up, and hardy pines, and the Hemlock Spruce, until it is richly overshadowed and embowered. But while its sh.o.r.es are being enriched, the soil-beds creep out with incessant growth, contracting its area, while the lighter mud-particles deposited on the bottom cause it to grow constantly shallower, until at length the last remnant of the lake vanishes,--closed forever in ripe and natural old age. And now its feeding-stream goes winding on without halting through the new gardens and groves that have taken its place.

The length of the life of any lake depends ordinarily upon the capacity of its basin, as compared with the carrying power of the streams that flow into it, the character of the rocks over which these streams flow, and the relative position of the lake toward other lakes. In a series whose basins lie in the same canon, and are fed by one and the same main stream, the uppermost will, of course, vanish first unless some other lake-filling agent comes in to modify the result; because at first it receives nearly all of the sediments that the stream brings down, only the finest of the mud-particles being carried through the highest of the series to the next below. Then the next higher, and the next would be successively filled, and the lowest would be the last to vanish. But this simplicity as to duration is broken in upon in various ways, chiefly through the action of side-streams that enter the lower lakes direct. For, notwithstanding many of these side tributaries are quite short, and, during late summer, feeble, they all become powerful torrents in springtime when the snow is melting, and carry not only sand and pine-needles, but large trunks and boulders tons in weight, sweeping them down their steeply inclined channels and into the lake basins with astounding energy. Many of these side affluents also have the advantage of access to the main lateral moraines of the vanished glacier that occupied the canon, and upon these they draw for lake-filling material, while the main trunk stream flows mostly over clean glacier pavements, where but little moraine matter is ever left for them to carry. Thus a small rapid stream with abundance of loose transportable material within its reach may fill up an extensive basin in a few centuries, while a large perennial trunk stream, flowing over clean, enduring pavements, though ordinarily a hundred times larger, may not fill a smaller basin in thousands of years.

The comparative influence of great and small streams as lake-fillers is strikingly ill.u.s.trated in Yosemite Valley, through which the Merced flows. The bottom of the valley is now composed of level meadow-lands and dry, sloping soil-beds planted with oak and pine, but it was once a lake stretching from wall to wall and nearly from one end of the valley to the other, forming one of the most beautiful cliff-bound sheets of water that ever existed in the Sierra. And though never perhaps seen by human eye, it was but yesterday, geologically speaking, since it disappeared, and the traces of its existence are still so fresh, it may easily be restored to the eye of imagination and viewed in all its grandeur, about as truly and vividly as if actually before us. Now we find that the detritus which fills this magnificent basin was not brought down from the distant mountains by the main streams that converge here to form the river, however powerful and available for the purpose at first sight they appear; but almost wholly by the small local tributaries, such as those of Indian Canon, the Sentinel, and the Three Brothers, and by a few small residual glaciers which lingered in the shadows of the walls long after the main trunk glacier had receded beyond the head of the valley.

Had the glaciers that once covered the range been melted at once, leaving the entire surface bare from top to bottom simultaneously, then of course all the lakes would have come into existence at the same time, and the highest, other circ.u.mstances being equal, would, as we have seen, be the first to vanish. But because they melted gradually from the foot of the range upward, the lower lakes were the first to see the light and the first to be obliterated. Therefore, instead of finding the lakes of the present day at the foot of the range, we find them at the top. Most of the lower lakes vanished thousands of years before those now brightening the alpine landscapes were born. And in general, owing to the deliberation of the upward retreat of the glaciers, the lowest of the existing lakes are also the oldest, a gradual transition being apparent throughout the entire belt, from the older, forested, meadow-rimmed and contracted forms all the way up to those that are new born, lying bare and meadowless among the highest peaks.

[Ill.u.s.tration: THE DEATH OF A LAKE.]

A few small lakes unfortunately situated are extinguished suddenly by a single swoop of an avalanche, carrying down immense numbers of trees, together with the soil they were growing upon. Others are obliterated by land-slips, earthquake taluses, etc., but these lake-deaths compared with those resulting from the deliberate and incessant deposition of sediments, may be termed accidental. Their fate is like that of trees struck by lightning.

The lake-line is of course still rising, its present elevation being about 8000 feet above sea-level; somewhat higher than this toward the southern extremity of the range, lower toward the northern, on account of the difference in time of the withdrawal of the glaciers, due to difference in climate. Specimens occur here and there considerably below this limit, in basins specially protected from inwas.h.i.+ng detritus, or exceptional in size. These, however, are not sufficiently numerous to make any marked irregularity in the line. The highest I have yet found lies at an elevation of about 12,000 feet, in a glacier womb, at the foot of one of the highest of the summit peaks, a few miles to the north of Mount Hitter. The basins of perhaps twenty-five or thirty are still in process of formation beneath the few lingering glaciers, but by the time they are born, an equal or greater number will probably have died.