Popular Science Monthly/Volume 58/March 1901/Pyramid Lake, Nevada

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PYRAMID LAKE, NEVADA.
By HAROLD W. FAIRBANKS, Ph.D.

BERKELEY, CAL.

NOT much more than fifty years ago the Great Basin region, lying between the Rocky Mountains and the Sierra Nevadas, was almost unknown. Previous to 1840, a few daring men had penetrated west of the Rocky Mountains. The route to Oregon had been traversed, and one party had crossed the southern portion of the Great Basin, but the main portion was unexplored.

The maps made of the country lying west, of the Rocky Mountains previous to the explorations of Fremont are most interesting, as showing the strange conceptions which men had formed of the geographic features of the region. The great Sierra Nevada range of California is entirely absent, and a number of rivers are marked as rising in the Rocky Mountains and flowing west into the Pacific.

One of these maps was used by Fremont, who first made known the real character of the region, and the journal of his wanderings in this desert waste is most interesting reading. Enabled as we are now to cross the deserts in a few hours in comfortable cars, with good maps at hand, and plenty to eat and drink, it is hard to place ourselves in the position of the early explorers of a vast and unknown region, where each day the problem of food and water has to be solved anew.

We owe much to Fremont for his daring explorations in the arid regions of the West. It was during his first expedition that he discovered Pyramid Lake, the subject of this sketch, but in trying to extricate himself and his party from the deserts, they nearly perished upon the snowy summits of the Sierra Nevada Mountains.

In the year 1843 Fremont conducted an exploring expedition to Oregon. As winter approached he turned southward from The Dalles, expecting to return to Salt Lake by way of Nevada. But upon getting into the deserts and fearing that he would not be able to cross them, he turned westward and, in the very heart of winter, attempted to cross the Sierras into California. This plan was based upon a misconception of the geography; for his map showed him no Sierra Nevada, but instead a great river called the Buenaventura, which was supposed to rise in the Rocky Mountains and flow westward into San Francisco Bay. Day after day as his party became more wearied, and food for the animals became scarcer, he watched for this river, thinking that every stream which they came to must be the one sought, but found invariably that
 
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Fig. l. Pyramid Island, Pyramid Lake.
 
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Fig. 2. Tufa Deposits by Pyramid Lake, showing Concentric Structure.

the streams flowed in the wrong direction and emptied into lakes without outlets or into the desert sands.

As the party (raveled southward into Nevada, they came upon one of the largest and most interesting of the lakes of the Great Basin. Fremont says in his journal: "Beyond, a defile between I he mountains descended rapidly about 2,000 feet; and filling all the lower space was a sheet of green water some twenty miles broad. It broke upon our eyes like the ocean. The waves were curling in the breeze and their green color showed it to be a body of deep water. For a long time we sat enjoying the view. It was like a gem in the mountains which from our position seemed to enclose it almost entirely." 'Thus runs (he narrative of the first white man who ever saw this great body of water. Of its source and general relations he knew nothing, but he hoped that it had an outlet and that the stream would lead him westward to California.

Traveling southward along the eastern shore of the lake, the party came in sight of a great rock rising from it, and camped upon the shore opposite. Fremont says: "It rose according to our estimate 600 feet above the water, and from the point we viewed it, presented a pretty exact outline of the great pyramid of Cheops. This striking feature suggested a name for the lake and I called it Pyramid Lake."

The lake thus discovered and named has had an interesting geological history, and is surrounded by many remarkable scenic features. It occupies the deepest portion of the basin of a much greater lake which once covered much of northwestern Nevada. This extinct lake has been named Lahonton, after an early French explorer.

It must be understood that the Great Basin, as its name signifies, is an extensive region with no outlet to the ocean. It is made up of innumerable faulted crust blocks, the elevated ones giving rise to the north and south ranges of mountains and the depressed ones to the desert basins lying between. Each local basin or valley has its own watershed limited by the mountains which surround it, but if for any cause the water supply from these mountains is in excess of the evaporation in the valley, a lake results, and if the supply is sufficient the lake will overflow its own basin and spread into the adjoining basins, rising to a height at which the water lost by evaporation exactly balances the inflow.

In this manner it was that the great Lake Lahonton spread over the valleys of northwestern Nevada during the glacial period. The Walker, Carson and Truckee rivers, with many smaller ones, all heading in the glacier-covered Sierras, were supplied with a great amount of water during the heavier precipitation of that period. In addition, the heat was not so great and consequently evaporation was less.

The ancient boundaries of this lake have been traced and carefully studied, and we know-that during its high-water stage it was second, in size, only to Lake Bonneville, another great lake of the same period which occupied the basin of Great Salt Lake. The total length of Lake Lahonton from north to south was not far from 250 miles, with a width from east to west of 180 miles. Its area was more than 8,000 square miles. It was an exceedingly irregular lake, however, for it was broken up by mountain ranges into many long and narrow arms, with deep bays and long peninsulas. At the time of its greatest expansion it still had no outlet, although one arm reached far westward into Honey Lake valley, California, and another one extended into southern Oregon.

As time passed on and precipitation decreased, the supplying streams became smaller and the lake began to shrink. The basins which had been connected at high water again were separated and so there at last resulted the conditions of the present day. Many of the lakes are still

PSM V58 D516 Terraces of lake lahonton north of pyramid lake.png

Fig. 3. Terraces of Lake Lahonton, North of Pyramid Lake.

shrinking, and it is difficult to tell how much of the ancient lake will eventually remain. Walker Lake, Carson Lake, Humboldt, Honey and Pyramid lakes are the remnants of the once far-reaching Lake Lahonton. The great valleys which the lake left bare are now among the most arid portions of Nevada. Notable among these is the Black Rock desert, where for many miles, and in some directions as far as the eye can reach, the barren clay floor of the old lake stretches away.

As the waters of Lake Lahonton receded they did so by stages and at every stopping-place left a well marked beach. These old beach terraces are among the most striking features of this region. One may travel for days over the desert with the old wave-cut benches circling the mountains far above him.

Pyramid Lake occupies the deepest of the basins of Lake Lahonton. It has a depth now of about 360 feet, but the waters of the ancient lake rose 500 feet higher, making its greatest depth at the time of maximum expansion nearly 1,000 feet. Pyramid Lake has a length of thirty miles and a maximum width of ten miles. It is fed by the Truckee River, which has its source in Lake Tahoe in the high Sierras. The lake is, of course, alkaline, as are all the lakes of the Great Basin, hut the water is not as strongly impregnated as some of them. It is well supplied with large trout, as well as several other kinds of fish. The water is unfit for people to drink, although it answers for stock.

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Fig. 4. Tufa Deposits, North End of Pyramid Lake.

High mountains come down to the lake, leaving in places scarcely room for a road, and although the waters are quiet as a rule, yet they are subject to sudden and violent storms.

At many points within the basin of the former lake, Lahonton, there are strange-appearing deposits of calcareous tufa, either encrusting the rocks or rising in curious and fantastic towers and domes. The waters of the lake were richly impregnated with calcium carbonate, derived in part from the incoming streams, but more largely probably from calcareous springs. As the lake waters receded, the salts in solution became more concentrated and soon began to form chemical precipitates upon projecting rocky points. In the port ion of the basin now occupied by Pyramid Lake the springs were more numerous and the water consequently more richly impregnated with lime. As a result, we find to-day in and about this lake the most interesting and remarkable tufa deposits known in all the Great Basin.

The tufa deposits are of various sorts and appearances, the differences being due to changes in the chemical properties of the water at various stages. Some of the forms are merely encrusting, and apparently structureless. Others show beautiful dendritic and interlacing figures, lapping over each other like the successive branches of some organic growth. The great deposits in Pyramid Lake have been built up in the form of towers, domes and pinnacles. The smaller ones bear a most striking resemblance to great thick mushrooms with a concentric

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Fig. 5. Tufa Domes, East shore of Pyramid Lake. Mushroom-like Form.

structure. These mushroom-like growths start from some projecting point or pebble and increase in size by precipitation from the surrounding water, until, massing together, the great domes and pinnacles have been built up, rising hundreds of feet in the air.

While these deposits are still being formed in Pyramid Lake, the large ones which rise so picturesquely from the water must, of course, have been formed before Lake Lahonton had entirely disappeared, and it has been only through the continued recession of the water that the deposits have become exposed to our observation.

Following the road northward along the west side of the lake, we pass many curious forms assumed by the tufa. Here is one upon a projecting point of the shore like an old ruined castle, there by the roadside a cluster of nearly spherical domes, partly broken down and showing the concentric inner structure. But upon the far side of the lake, standing out clearly in the desert air, rises the most attractive feature of all. It is Pyramid Island, and we do no! wonder at Fremont's naming it as he did.

Hiring a boat at a little ranch by the shore, we rowed across the clear and quiet waters of the lake to Pyramid and Anaho islands. The latter island is completely encrusted with the dendritic In fa. which from a distance appears like the overlapping scales upon some gigantic animal.

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Fig. 6. Mushroom Rock, Anaho Island.

Upon the eastern side of the islands, rising from the edge of the water there is a most picturesque deposit, known as the mushroom rock and shown in the accompanying photograph. Rising from a firm base, the deposit becomes smaller, and then at the top swells out in a spherical head.

Pyramid Island next demanded attention, and a row of a mile farther brought us close under its towering cliffs. It rises almost vertically from the water, but its sides soon become more sloping and terminate in a point nearly 300 feet high. Its shape is almost symmetrical from whichever side it is viewed. Its surface is of a very light color, and consequently it is a conspicuous landmark from all points about the lake.
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Fig. 7. One of the Pinnacles, North End of Pyramid Island.
 
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Fig, 8. Tufa Crags, North End of Pyramid Lake.

It is but a short distance from the island to the eastern shore, where Fremont camped and made the sketch which accompanies his narrative. This is a favorite camping spot for the Indians while engaged in fishing. Upon a projecting point near here there is a large cluster of very perfect tufa domes. They are among the finest about the lake. Several of them stand out from the others and exhibit finely their manner of growth. Starting from a point upon the rocks, the mushroom-like form spreads out until eight or ten feet in diameter and is then completed by a perfect hemispherical upper surface.

Long before we reached the northern end of the lake our attention was attracted by a long line of sharply pointed crags and islands, extending out more than a mile into the lake. The most of these can be reached only by water, so securing a boat from an Indian, we pulled across the three miles of water intervening.

This group of tufa domes and crags is by far the most interesting of any about the lake. Exceedingly picturesque is the effect as one rows among them, gliding over the quiet waters, from whose clear depths rise these fantastic forms. Some are low and rounded, their mammillary or botryoidal surfaces made up of an aggregation of domes. Others are more angular, rising sharply from the water's edge to a height of 300 feet. Beautiful beaches of clean sand stretch between those nearer the shore, sand marked most regularly by the waves of the lake at different stages, as it slowly recedes through the summer months. Upon a warm summer's day when the lake glistens in the sunlight, the caves in the tufa offer most inviting retreats, and the clean gently shelving beaches and comfortably tempered water are irresistible. One enjoys a bath in the mineral waters, but must be careful not to stay in them too long, for they are so strongly impregnated with alkalies that the skin is soon affected.

During the high-water stages of the lake these picturesque towers grew up beneath its surface from numerous warm springs carrying lime in solution. Springs still issue at various places, and the tufa can be observed in process of formation. It is soft and spongy, crushing under one's feet as one walks over the surface, but slightly above the summer level of the lake.

These rocks, as well as those at the southern end of the lake, are the resort of thousands of sea birds, many of which nest here. Pelicans, sea gulls, terns, geese, ducks, etc., abound. The pelican rookeries are large and particularly interesting, with the great uncouth birds swimming about in large numbers and the downy young waddling around the nests. The cavities and nooks in the tufa offer especially convenient nesting places for many of the birds. Then, too, they are seldom molested in this remote place.

Another interesting feature about the life of these rocks is the multitude of spiders. One cannot climb over them without being covered with the webs and distributing hundreds of the little insects. But few bushes grow upon the tufa, for the rainfall here is very slight, and they are clearly revealed in all their nakedness.

Exceedingly barren are the shores of this great lake, except at two points where springs furnish water for irrigation. The Truckee River has rich bottoms along its lower course, occupied by Indians who seem to be fairly well civilized.

Although the lake is so isolated, its scenery is remarkable in the extreme, and it deserves to be better known. More plainly than is usually the case, the history of the ancient lake which occupied these valleys is recorded on the slopes of the surrounding mountains and in the strange tufa deposits which rise out of the waters of its modern representative, Pyramid Lake. Rising and falling with the different seasons, the lake seems to have slight hold upon life. If the Truckee River should be entirely diverted to Winnemucca Lake, the waters of Pyramid Lake would undoubtedly shrink to insignificant proportions. The same effect would be brought about if the aridity of the Great Basin region should increase, and the precipitation upon the Sierra Nevada become less than at present.

Let us hope that, in the swinging of the pendulum from arid to more moist conditions and back again, the lakes of the Great Basin are not doomed to extinction, but that they may again increase in size, repeating the conditions of the past.