[Illustration: FIG. 124.--A YELLOW PINE FOREST] After getting well into the yellow pine forest, we soon come upon other trees that contend with the pines for a footing upon the slopes and for a bit of the sunshine. Among these the black oaks deserve special mention, for in places they form dense groves upon the ridges. The cedars, with their rich brown bark and flat, drooping branches, are easily recognized. As these trees grow old they become gnarled and knotty and very picturesque. [Illustration: FIG. 125.--SUGAR PINE] We first meet that "king of pines," the sugar pine, upon the more shaded mountain slopes. Although higher up, on barren, rocky ridges, this tree grows to noble size, yet it cannot withstand heat and dryness. Our attention may be first called to the sugar pine by the slender cones, ten to fifteen inches in length, which are scattered over the ground. Then, as we look up to see whence the cones come, our eyes light upon the smooth trunks, often over six feet in diameter and reaching up one hundred and fifty feet before the branches appear. From the ends of the long, drooping branches hang slender green cones. The name of this pine is derived from the fact that a white sugar gathers in little bunches at the spots where the trunk has been injured. This sugar is pleasant to the taste and somewhat medicinal. [Illustration: FIG. 126.--ZONE OF THE FIR FOREST, SIERRA NEVADA MOUNTAINS] The wood of the sugar pine, which is white and fine-grained, is of greater value commercially than that of any of the other pines. This fact leads the shake-maker and lumberman to seek out the noble tree and mark it for destruction. The sugar pine, when once destroyed in a given locality, rarely replaces itself, as it is crowded out by the more vigorous conifers. Scattered through the forests of yellow pine, cedar, and sugar pine is the Douglas spruce, commonly known in the market as the Oregon pine. This is the most important forest tree in Oregon and Washington. It often grows to a height of three hundred feet, and forms dense forests for hundreds of miles along the base and western slope of the Cascade Range. In Washington it is found growing down to the sea-level, but in the Sierra Nevada the requisite moisture for its growth is not found much below an elevation of four thousand feet. As we go upward the pines become fewer and the firs and "Big Trees" take their places. The Big Trees are found in scattered groves, at an elevation of five thousand to eight thousand feet, for a distance of two hundred and fifty miles along the slopes of the Sierra Nevada mountains. The Sequoia, as the genus is called, which also includes the redwood of the Coast ranges, is in many respects the most remarkable of all our coniferous trees. [Illustration: FIG. 127.--THE BIG TREE FOREST IN THE SIERRA NEVADA MOUNTAINS]