Part 10 (2/2)
Soundings have shown that the water is fourteen hundred feet deep; that is, a little more than a quarter of a mile. With the exception of Crater Lake, in Oregon, this is the deepest body of water in the United States. It is also interesting to note that the bottom of the lake is fully three hundred feet below the level of the ocean.
How could a river cut a channel for itself so far below the ocean level? Rivers cannot do work of this kind unless they have a swift current; moreover, as they empty into the ocean, their beds must be above sea level. Some people think that the great glacier, which certainly at some time occupied the depression in which the lake lies, dug out the canon. This glacier was over three thousand feet in thickness, for the rocks are grooved and polished to a height of nearly two thousand feet above the surface of the water. It is, nevertheless, improbable that the glacier did anything more than deepen and widen the canon somewhat. It was certainly made, as we at first supposed, by a river which flowed through it at some remote period. At that time the land of our Pacific coast must have stood many hundred feet higher than it does now.
[Ill.u.s.tration: FIG. 59.--GOAT MOUNTAIN, NORTH Sh.o.r.e OF LAKE CHELAN]
The surface of Lake Chelan is a little more than three hundred feet above the bed of the Columbia River, which flows through a deep canon only three miles distant. If we could remove the dam of glacial boulders and gravel at the lower end of the lake, the water would be lowered only three hundred feet. The lake would not be drained, for it is very much deeper. Now here is another puzzle for us: the bottom of the lake is more than one thousand feet below the level of the Columbia. We shall have to go still farther back into the past to get a satisfactory explanation this time.
Hundreds of thousands of years ago there was no plateau filling central Was.h.i.+ngton, and no Columbia River crossing it. The Cascade Range stood where we see it to-day, and the region of the plateau was a broad valley, toward which flowed the streams that had already cut canons upon the eastern side of the range. These streams probably united in a river emptying westward into the Pacific by a course now unknown. The sh.o.r.es of the ocean were farther west than at present, for the land stood higher.
The canon of Lake Chelan was made by a river of this period, which through many long years gradually deepened and enlarged its channel.
The river worked just as we see rivers working at the present time, for throughout all the history of the earth rivers have not changed their habits. Then came the long period of volcanic eruptions. Our Northwest was flooded by fiery lava, which built up the Columbia plateau and buried under thousands of feet of rock the old river valley into which the canon of Chelan emptied.
Then streams of water began to flow over the plateau from the higher mountains above the reach of the lava. These streams formed the Columbia River, which sought the easiest way to the sea, and finally excavated a canon for hundreds of miles. In a portion of its course the river came close to the edge of the Cascade Range. The ancient canon of Lake Chelan had been dammed up by the lava, and a lake occupied a portion of the former bed of the river. The Columbia could not cut its channel deep enough to drain the lake, and there it remained.
[Ill.u.s.tration: FIG. 60.--LOOKING DOWN LAKE CHELAN FROM THE UPPER END]
Then another change came: the climate grew cold and heavy snows gathered upon the Cascade Range. The snow did not all melt during the summers, but went on increasing from year to year. The ma.s.ses of snow moved gradually down the mountain slopes, growing more and more icy until they became true glaciers.
In this manner it came about that a river of ice occupied the canon in which the old lake lay, and, displacing its waters, sc.r.a.ped and ground out the bottom and sides. The moving ice deposited the waste material at the lower end of the canon, where it joined the Columbia River, the canon of which was also occupied by a glacier coming from farther north. When the glacier began to retreat up the Chelan canon, it left a great ma.s.s of rock debris, forming a dam between its basin and the Columbia. After the ice had disappeared, water collected in the canon above the dam, and the narrow, deep lake was formed, enclosed within granite walls.
As the snows melted, forests spread over the mountains, the bear, deer, and mountain goats came back again, while the streams, bringing down earth and rocks, began their work of filling up the lake. This task they will succeed in accomplis.h.i.+ng some day unless something unforeseen happens to prevent. A valley, composed partly of meadow and partly of boulder-covered slopes, will then have taken the place of the lake.
THE NATIVE INHABITANTS OF THE PACIFIC SLOPE
The explorers and early settlers found a native race occupying nearly every portion of our continent. These people had many characteristics in common and were all called Indians. It is believed that they came originally from Asia, but their migration and scattering occurred so long ago that they have become divided into many groups, each having its own language and customs.
In the western portion of the country, where the surface is broken by numerous barriers, such as mountains and deserts, almost every valley was found to be occupied by a distinct group of Indians called a ”tribe.” The language of each tribe differed so much from the languages of adjoining tribes that they could with difficulty understand one another. These tribes were almost continually at war.
The Indians upon the Pacific slope were generally found to be inferior in most respects to those living in the central and eastern portions of the continent. One might suppose that the tribes possessing the fair and fertile valleys of California would be the most advanced in civilization, but such was not the case. Many of them were among the most degraded upon the continent. They seemed unable to adapt themselves to the white man and his ways, and in the older settled districts they have now nearly disappeared. In the newer portions of the Northwest and along the coast toward Alaska the Indians have not yet come into so direct contact with the white men, and remain more nearly in their primitive condition.
When the Indians of central California were first seen, they wore but little clothing, and knew how to construct only the simplest dwellings for protection from the weather. They did not cultivate the soil, nor did they hunt a great deal, although the country abounded with game. Along the larger streams fish was an important article of food, but in other places, acorns, pine nuts, and roots const.i.tuted the main supplies. The acorns were ground in stone mortars and made into soup or into a kind of bread. These Indians have often been called Diggers because they depended so largely for their living upon the roots which they dug.
It would seem natural that about San Francis...o...b..y the natives should have used canoes, but, according to early travellers, they had none. When they wished to go out upon the water they built rafts of bundles of rushes or tules tied together.
At favorable points along the sh.o.r.e the Indians collected for their feasts, and these spots are now indicated by heaps of sh.e.l.ls, in some places forming mounds of considerable size. Many interesting implements have been dug from these mounds, or kitchen middens as they are sometimes called. In the mountains the sites of the villages are marked by chips of obsidian (a volcanic gla.s.s used in making arrow-tips) and by holes in the flat surfaces of granitic rocks near some spring or stream. These holes were made for the purpose of grinding acorns or nuts.
Many of the Indian tribes developed great skill in the weaving of baskets, which they used for many different purposes. The baskets are still made in some places, and are much sought after because of their beauty.
The Indians of northern California in building their homes dug round, shallow holes, over which poles were bent in the form of a half-circle, and then tied together at the top. Bark was laid upon the outside, and earth was thrown over the whole structure.
[Ill.u.s.tration: FIG. 61.--HOLES IN ROCK, MADE FOR GRINDING FOOD]
”Sweat houses” were built in much the same manner, and were used chiefly during the winter. When an Indian wished to take a sweat, hot stones were placed in one of these houses, and after he had entered and all openings were closed, he poured water upon the stones until the room was filled with steam. After enduring this process as long as he desired, the Indian came out and plunged into the cold water of a near-by stream. As may be imagined, such a bath often resulted disastrously to the weak or sick.
The fact that the California Indians could support themselves without any great exertion undoubtedly had the effect of making them indolent, while in the desert regions of the Great Basin the struggle for something to eat was so severe that it kept the natives in a degraded condition.
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