Our four volcanic national parks exemplify four states of volcanic history. Lassen Peak is semiactive; Mount Rainier is dormant; Yellowstone is dead, and Crater Lake marks the spot through which a volcano collapsed and disappeared. Rainier’s usefulness as a volcanic example, however, is lost in its supreme use-fulness as a glacial exhibit. The student of glaciers who begins here with the glacier in action, and then studies the effects of glaciers upon igneous rocks among the cirques of the Sierra, and upon sedimentary rocks in the Glacier National Park, will study the masters; which, by the way, is a tip for universities contemplating summer field-classes.
Upon the truncated top of Mount Rainier, nearly three miles in diameter, rise two small cinder cones which form, at the junction of their craters, the mountain’s rounded snow-covered summit. It is known as Columbia Crest. As this only rises four hundred feet above the older containing crater, it is not always identified from below as the highest point. Two commanding rocky elevations of the old rim, Point Success on its southwest side, 14,150 feet, and Liberty Cap on its northwest side, 14,112 feet, appear to be, from the mountain’s foot, its points of greatest altitude.
Rainier’s top, though covered with snow and ice, except in spots bared by internal heat, is not the source of its glaciers, although its extensive ice-fields flow into and feed several of them. The glaciers them-selves, even those continuous with the summit ice, really originate about four thousand feet below the top in cirques or pockets which are principally fed with the tremendous snows of winter, and the wind sweepings and avalanches from the summit. The Pacific winds are charged heavily with moisture which descends upon Rainier in snows of great depth. Even Paradise Park is snowed under from twelve to thirty feet. There is a photograph of a ranger cabin in February which shows only a slight snow-mound with a hole in its top which locates the hidden chimney. F. E. Matthes, the geologist, tells of a snow level of fifty feet depth in Indian Henry’s Hunting Ground, one of Rainier’s most beautiful parks, in which the wind had sunk a crater-like hollow from the bottom of which emerged a chimney. These snows replenish the glaciers, which have a combined surface of forty-five square miles, along their entire length, in addition to making enormous accumulations in the cirques.
Beginning then in its cirque, as a river often begins in its lake, the glacier flows downward, river-like, along a course of least resistance. Here it pours over a precipice in broken falls to flatten out in perfect texture in the even stretch below. Here it plunges down rapids, breaking into crevasses as the river in corresponding phase breaks into ripples. Here it rises smoothly over rocks upon its bottom. Here it strikes against a wall of rock and turns sharply. The parallel between the glacier and the river is striking and consistent, notwithstanding that the geologist for technical reasons will quarrel with you if you picturesquely call your glacier a river of ice. Any elevated view-point will disclose several or many of these mighty streams flowing in snake-like curves down the mountainside, the greater streams swollen here and there by tributaries as rivers are swollen by entering creeks. And all eventually reach a point, determined by temperature and therefore not constant, where the river of ice becomes the river of water.
Beginning white and pure, the glacier gradually clothes itself in rock and dirt. Gathering as it moves narrow edges of matter filched from the shores, later on it heaps these up upon its lower banks. They are lateral moraines. Two merging glaciers unite the material carried on their joined edges and form a medial moraine, a ribbon broadening and thickening as it descends; a glacier made up of several tributaries carries as many medial moraines. It also carries much unorganized matter fallen from the cliffs or scraped from the bottom. Approaching the snout, all these accumulations merge into one moraine; and so soiled has the ice now become that it is difficult to tell which is ice and which is rock. At its snout is an ice-cave far inside of which the resultant river originates.
But the glacier has one very important function which the river does not share. Far up at its beginnings it freezes to the back wall of its cirque, and, moving forward, pulls out, or plucks out, as the geologists have it, masses of rock which it carries away in its current. The resulting cavities in the back of the cirque fill with ice, which in its turn freezes fast and plucks out more rock. And presently the back wall of the cirque, undermined, falls on the ice and also is carried away. There is left a precipice, often sheerly perpendicular; and, as the process repeats itself, this precipice moves backward. At the beginning of this process, it must be understood, the glacier lies upon a tilted surface far more elevated than now when you see it in its old age, sunk deep in its self-dug trench; and, while it is plucking backward and breaking off an ever-increasing precipice above it, it is plucking down-ward, too. If the rock is even in structure, this down-ward cutting may be very nearly perpendicular, but if the rock lies in strata of varying hardness, shelves form where the harder strata are encountered because it takes longer to cut them through; in this way are formed the long series of steps which we often see in empty glacial cirques.
By this process of backward and downward plucking, the Carbon Glacier bit its way into the north side of the great volcano until it invaded the very foundations of the summit and created the Willis Wall which drops avalanches thirty-six hundred feet to the glacier below. Willis Wall is nearly perpendicular because the lava rock at this point was homogeneous. But in the alternating shale and limestone strata of Glacier National Park, on the other hand, the glaciers of old dug cirques of many shelves. The monster ice-streams which dug Glacier’s mighty valleys have vanished, but often tiny remainders are still seen upon the cirques’ topmost shelves.
So we see that the glacier acquires its cargo of rock not only by scraping its sides and plucking it from the bottom of its cirque and valley, but by quarrying backward till undermined material drops upon it; all of this in fulfilment of Nature’s purpose of wearing down the highlands for the upbuilding of the hollows.
This is not the place for a detailed description of Mount Rainier’s twenty-eight glaciers. A glance at the map will tell something of the story. Extending northeasterly from the summit will be seen the greatest unbroken glacial mass. Here are the Emmons and the Winthrop Glaciers, much the largest of all. This is the quarter farthest from the sun, upon which its rays strike at the flattest angle. The melting then is least here. But still a more potent reason for their larger mass is found in their position on the lee quarter of the peak, the prevailing winds whirling in the snow from both sides.
The greater diversification of the other sides of the mountain with extruding cliffs, cleavers, and enormous rock masses tends strongly to scenic variety and grandeur. Some of the rock cleavers which divide glaciers stand several thousand feet in height, veritable fences. Some of the cliffs would be mountains of no mean size elsewhere, and around their sides pour mighty glacial currents, cascading to the depths below where again they may meet and even merge.
The Nisqually Glacier naturally is the most celebrated, not because of scenic superiority, but because it is the neighbor and the playground of the visiting thousands. Its perfect and wonderful beauty are not in excess of many others; and it is much smaller than many. The Cowlitz Glacier near by exceeds it in size, and is one of the stateliest; it springs from a cirque below Gibraltar, a massive near-summit rock, whose well-deserved celebrity is due in some part to its nearness to the travelled summit trail. The point I am making is not in depreciation of any of the celebrated sights from the southern side, but in emphasis of the fact that a hundred other sights would be as celebrated, or more celebrated, were they as well known. The Mount Rainier National Park at this writing is replete with splendors which are yet to be discovered by the greater travelling public.
The great north side, for instance, with its mighty walls, its magnificently scenic glaciers, its lakes, canyons, and enormous areas of flowered and forested pleasure-grounds, is destined to wide development; it is a national park in itself. Already roads enter to camps at the foot of great glaciers. The west side, also, with its four spectacular glaciers which pass under the names of Mowich and Tahoma, attains sublimity; it remains also for future occupation.
Many of the minor phenomena, while common also to other areas of snow and ice, have fascination for the visitor. Snow-cups are always objects of interest and beauty. Instead of reducing a snow surface evenly, the warm sun sometimes melts it in patterned cups set close together like the squares of a checker-board. These deepen gradually till they suggest a gigantic honeycomb, whose cells are sometimes several feet deep. In one of these, one summer day in the Sierra, I saw a stumbling horse deposit his rider, a high official of one of our Western railroads; and there he sat helpless, hands and feet emerging from the top, until we recovered enough from laughter to help him out.
Pink snow always arouses lively interest. A microscopic plant, Protococcus nivalis, growing in occasional patches beneath the surface of old snow gradually emerges with a pink glow which sometimes covers acres. TOn the tongue its flavor suggests water-melon. No doubt many other microscopic plants thrive in the snow-fields and glaciers which remain in-visible for lack of color. Insects also inhabit these glaciers. There are several Thysanura, which suggest the sand-fleas of our seashores, but are seldom noticed because of their small size. More noticeable are the Mesenchytraeus, a slender brown worm, which attains the length of an inch. They may be seen in great numbers on the lower glaciers in the summer, but on warm days retreat well under the surface.
The extraordinary forest luxuriance at the base of Mount Rainier is due to moisture and climate. The same heavy snowfalls which feed the glaciers store up water-supplies for forest and meadow. The winters at the base of the mountain are mild.
The lower valleys are covered with a dense growth of fir, hemlock, and cedar. Pushing skyward in competition for the sunlight, trees attain great heights. Protected from winter’s severity by the thickness of the growth, and from fire by the dampness of the soil, great age is assured, which means thick and heavy trunks. The Douglas fir, easily the most important timber-tree of western America, here reaches its two hundred feet in massive forests, while occasional individuals grow two hundred and fifty to two hundred and seventy feet with a diameter of eight feet. The bark at the base of these monsters is sometimes ten inches thick. The western hemlock also reaches equal heights in competition for the light, with diameters of five feet or more. Red cedar, white pines of several varieties, several firs, and a variety of hemlocks complete the list of conifers. Deciduous trees are few and not important. Broad-leaved maples, cottonwoods, and alders are the principal species.
Higher up the mountain-slopes the forests thin and lessen in size, while increasing in picturesqueness. The Douglas fir and other monsters of the lower levels disappear, their places taken by other species. At an altitude of four thousand feet the Englemann spruce and other mountain-trees begin to appear, not in the massed ranks of the lower levels, but in groves bordering the flowered opens.
The extreme limit of tree growth on Mount Rainier is about seven thousand feet of altitude, above which one finds only occasional distorted, wind-tortured mountain-hemlocks. There is no well-defined timber-line, as on other lofty mountains. Avalanches and snow-slides keep the upper levels swept and bare.
The wild-flower catalogue is too long to enumerate here. John Muir expresses the belief that no other subalpine floral gardens excel Rainier’s in profusion and gorgeousness. The region differs little from other Pacific regions of similar altitude in variety of species; in luxuriance it is unsurpassed.