The Silver, or Yellow, Pine, as it is commonly called, ranks second among the pines of the Sierra as a lumber tree, and almost rivals the Sugar Pine in stature and nobleness of port.  Because of its superior powers of enduring variations of climate and soil, it has a more extensive range than any other conifer growing on the Sierra.  On the western slope it is first met at an elevation of about 2000 feet, and extends nearly to the upper limit of the timber line.  Thence, crossing the range by the lowest passes, it descends to the eastern base, and pushes out for a considerable distance into the hot volcanic plains, growing bravely upon well-watered moraines, gravelly lake basins, arctic ridges, and torrid lava-beds; planting itself upon the lips of craters, flourishing vigorously even there, and tossing ripe cones among the ashes and cinders of Nature’s hearths.

The average size of full-grown trees on the western slope, where it is associated with the Sugar Pine, is a little less than 200 feet in height and from five to six feet in diameter, though specimens may easily be found that are considerably larger.  I measured one, growing at an elevation of 4000 feet in the valley of the Merced, that is a few inches over eight feet in diameter, and 220 feet high.

Where there is plenty of free sunshine and other conditions are favorable, it presents a striking contrast in form to the Sugar Pine, being a symmetrical spire, formed of a straight round trunk, clad with innumerable branches that are divided over and over again.  About one half of the trunk is commonly branchless, but where it grows at all close, three fourths or more become naked; the tree presenting then a more slender and elegant shaft than any other tree in the woods.  The bark is mostly arranged in massive plates, some of them measuring four or five feet in length by eighteen inches in width, with a thickness of three or four inches, forming a quite marked and distinguishing feature.  The needles are of a fine, warm, yellow-green color, six to eight inches long, firm and elastic, and crowded in handsome, radiant tassels on the upturning ends of the branches.  The cones are about three or four inches long, and two and a half wide, growing in close, sessile clusters among the leaves.

[Illustration:  PINUS PONDEROSA.]

The species attains its noblest form in filled-up lake basins, especially in those of the older yosemites, and so prominent a part does it form of their groves that it may well be called the Yosemite Pine.  Ripe specimens favorably situated are almost always 200 feet or more in height, and the branches clothe the trunk nearly to the ground, as seen in the illustration.