But no one can picture this wonderful valley with pen or brush or camera and give its real charm.  You must see it yourself to know and understand the beauty of great mountains and falling waters, of Mirror Lake with its fine reflections of the surrounding scenery, and of the rushing torrent of the Merced River in its swift coursing through this mighty canon of the Yosemite.  Thousands of tourists and sightseers visit the valley from May to October.  Then snow begins to fall and winter sets in, as it does everywhere in the high Sierras.  Very deep snow-drifts cover the ground, lakes and rivers freeze, and the great falls are fringed with icicles, while a large ice cone forms at the foot of the falling water.  Many beautiful pictures may be found in the valley in winter when Jack Frost is ruler of all the snow-clad, ice-bound canon.

Scattered throughout the Sierras are other valleys almost as fine as the Yosemite.  These are not often reached by the army of summer sight-seers, but true mountaineers find them.  One valley which has fine scenery is the Grand Canon of the Tuolumne, the gorge being twenty-five miles long, with walls so high and steep that once entered one must go through to the end.  The Tuolumne River rushes, with terrible force and speed, in cascades and rapids down the granite stairway which is the floor of this canon.  The walls of the gorge rise so high that the traveller only sees a tiny strip of blue sky far above him, and the great pine trees on top of these cliff walls seem only the length of one’s finger.

It is supposed that all these valleys have been formed by glaciers, which during the ice age, thousands of years ago, filled the canons and swept over the mountains.  These masses of ice, moving very slowly, ground and tore up the rocks under and around them till deep gorges and steep, high cliffs were left in their tracks.  Most of the glaciers melted long ago, but on Mount Lyell, on Shasta, and a few of the Sierra summits may still be found those ever-living ice-rivers, the one on Mount Lyell being the source of the Tuolumne River.

California is rich in lakes, especially in the mountains where the melting snows gather in every hollow and form lakelets in chains or groups, or in one large body of water like Tahoe, Donner, or Tenaya lakes.

One of the most beautiful lakes in the world is Lake Tahoe.  It is six thousand feet above sea-level, and the mountains around it rise four thousand feet higher.  On these peaks snow-drifts lie the year round above the “snow-line,” as a height over eight or nine thousand feet is called.  Nevada, treeless and barren, is on the eastern side of Lake Tahoe, while the western or California side is green and thickly wooded with beautiful pines.  But the first thing one would notice, perhaps, is the wonderful clearness of the lake water.  As one stands on the wharf the steamer Tahoe seems to be hanging in the clear green depths with her keel