Page:Popular Science Monthly Volume 58.djvu/516

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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