This early history is clearly explained by the present rivers of southeastern Alaska. Of those draining glaciers that discharge into arms of the sea, only the rills on the surface of the ice, and upboiling, eddying, turbid currents in the tide water in front of the terminal ice wall, are visible. Where glaciers, in the first stage of decadence, have receded from the shore, short sections of the trunks of the rivers that are to take their places may be seen rushing out from caverns and tunnels in the melting front,—rough, roaring, detritus-laden torrents, foaming and tumbling over outspread terminal moraines to the sea, perhaps without a single bush or flower to brighten their raw, shifting banks. Again, in some of the warmer cañons and valleys from which the trunk glaciers have been melted, the main trunks of the rivers are well developed, and their banks planted with fine forests, while their upper branches, lying high on the snowy mountains, are still buried beneath shrinking residual glaciers; illustrating every state of development, from icy darkness to light, and from muddiness to crystal clearness.
Now that the hard grinding sculpture work of the glacial period is done, the whole bright band of Sierra rivers run clear all the year, except when the snow is melting fast in the warm spring weather, and during extraordinary winter floods and the heavy thunderstorms of summer called cloud-bursts. Even then they are not muddy above the foothill mining region, unless the moraines have been loosened and the vegetation destroyed by sheep; for the rocks of the upper basins are clean, and the most able streams find but little to carry save the spoils of the forests,—trees, branches, flakes of bark, cones, leaves, pollen dust, etc.,—with scales of mica, sand grains, and boulders, which are rolled along the bottom of the steep parts of the main channels. Short sections of a few of the highest tributaries heading in glaciers are of course turbid with finely ground rock mud, but this is dropped in the first lakes they enter.
On the northern part of the range, mantled with porous fissured volcanic rocks, the fountain waters sink and flow below the surface for considerable distances, groping their way in the dark like the draining streams of glaciers, and at last bursting forth in big generous springs, filtered and cool and exquisitely clear. Some of the largest look like lakes, their waters welling straight up from the bottom of deep rock basins in quiet massive volume giving rise to young rivers. Others issue from horizontal clefts in sheer bluffs, with loud tumultuous roaring that may be heard half a mile or more. Magnificent examples of these great northern spring fountains, twenty or thirty feet deep and ten to nearly a hundred yards wide, abound on the main branches of the Feather, Pitt, McCloud, and Fall rivers.
The springs of the Yosemite Park, and the high Sierra in general, though many times more numerous, are comparatively small, oozing from moraines and snowbanks in thin, flat irregular currents which remain on the surface or near it, the rocks of the south half of the range being mostly flawless impervious granite; and since granite is but slightly soluble, the streams are particularly pure. Nevertheless, though they are all clear, and in the upper and main central forest regions delightfully lively and cool, they vary somewhat in color and taste as well as temperature, on account of differences, however slight, in exposure, and in the rocks and vegetation with which they come in contact. Some are more exposed than others to winds and sunshine in their falls and thin plumelike cascades; the amount of dashing, mixing, and airing the waters of each receive varies considerably; and there is always more or less variety in the kind and quantity of the vegetation they flow through, and in the time they lie in shady or sunny lakes and bogs.
“Fountain Snow” on the High Sierras (Mt. Lyell Group).
The water of one of the branches of the north fork of Owens River, near the southeastern boundary of the Park, at an elevation of ninety-five hundred feet above the sea, is the best I ever found. It is not only delightfully cool and bright, but brisk, sparkling, exhilarating, and so positively delicious to the taste that a party of friends I led to it twenty-five years ago still praise it, and refer to it as “that wonderful champagne water;” though, comparatively, the finest wine is a coarse and vulgar drink. The party camped about a week in a pine grove on the edge of a little round sedgy meadow through which the stream ran bank full, and drank its icy water on frosty mornings, before breakfast, and at night about as eagerly as in the heat of the day; lying down and taking massy draughts direct from the brimming flood, lest the touch of a cup might disturb its celestial flavor. On one of my excursions I took pains to trace this stream to its head springs. It is mostly derived from snow that lies in heavy drifts and avalanche heaps on or near the axis of the range. It flows first in flat sheets over coarse sand or shingle derived from a granite ridge and the metamorphic slates of Red Mountain. Then, gathering its many small branches, it runs through beds of moraine material, and a series of lakelets and meadows and frosty juicy bogs bordered with heathworts and linked together by short bouldery reaches. Below these, growing strong with tribute drawn from many a snowy fountain on either side, the glad stream goes dashing and swirling through clumps of the white-barked pine, and tangled willow and alder thickets enriched by the fragrant herbaceous vegetation usually found about them. And just above the level camp meadow it is chafed and churned and beaten white over and over again in crossing a talus of big earthquake boulders, giving it a very thorough airing. But to what the peculiar indefinable excellence of this water is due I don’t know; for other streams in adjacent cañons are aired in about the same way, and draw traces of minerals and plant essences from similar sources. The best mineral water yet discovered in the Park flows from the Tuolumne soda springs, on the north side of the Big Meadow. Mountaineers like it and ascribe every healing virtue to it, but in no way can any of these waters be compared with the Owens River champagne.
It is a curious fact that the waters of some of the Sierra lakes and streams are invisible, or nearly so, under certain weather conditions. This is noticed by mountaineers, hunters, and prospectors, wide-awake, sharp-eyed observers, little likely to be fooled by fine whims. One of these mountain men, whom I had nursed while a broken leg was mending, always gratefully reported the wonders he found. One, returning from a trip on the head waters of the Tuolumne, he came running eagerly, crying: “Muir, I’ve found the queerest lake in the mountains! It’s high up where nothing grows; and when it isn’t shiny you can’t see it, and you walk right into it as if there was nothing there. The first you know of that lake you are in it, and get tripped up by the water, and hear the splash.” The waters of Illilouette Creek are nearly invisible in the autumn; so that, in following the channel, jumping from boulder to boulder after a shower, you will frequently drag your feet in the apparently surfaceless pools.
Excepting a few low, warm slopes, fountain snow usually covers all the Yosemite Park from November or December to May, most of it until June or July, while on the coolest parts of the north slopes of the mountains, at a height of eleven to thirteen thousand feet, it is perpetual. It seldom lies at a greater depth than two or three feet on the lower margin, ten feet over the middle forested region, or fifteen to twenty feet in the shadowy cañons and cirques among the peaks of the Summit, except where it is drifted, or piled in avalanche heaps at the foot of long converging slopes to form perennial fountains.