Timber-line is one of Nature's most interesting regions. Its location and also its marked characteristics are determined by climatic conditions—by cold, snow, wind, moisture, and drought. Wind is a most influential factor. The position of thousands of miles of timber-line is determined by it. At timber-line the Storm King says, "Thus far and no farther." The trees do not heed, but persistently try to go on, and the struggle for existence becomes deadly. They appear like our unfortunate brothers whom fate has chained in the slums. The trees try to stand erect and climb onward and upward, but in vain. The elements are relentless. The wind blows off their arms and cuts them with flying sand. The cold dwarfs them, and for nine months in the year the snow tries to twist and crush the life out of them. Some become hunchbacks; others are broken, bent, and half-flayed; while a few crouch behind the rocks. Many stretches of timber-line are so battered by the wind that the trees have the appearance of having been recently swept by a cyclone, or overthrown by a giant roller.
What a weird scene! Here for ages has been the line of battle between the woods and the weather. At most timber-lines the high winds blow chiefly from one direction. Many of the trees possess a long, vertical fringe of limbs to leeward, being limbless and barkless to stormward. Each might serve as an impressive symbolic statue of a wind-storm. Permanently, their limbs stream to leeward together, with fixed bends and distortions, as if cast in metal at the height of a storm. Many present an unconquerable and conscious appearance, like tattered pennants or torn, triumphant battle-flags of the victorious forest! Some trees are several inches in diameter and only a few inches in height; others are creeping away from the direction of the storms, retreating from life's awful battle. All beauty and nobleness of appearance are lost. But the trees have done their best.
Timber-line is not stationary. In most places it is advancing, climbing the heights. This advance is confined mainly to moist territory. In a few dry places the ranks are losing ground—are being driven back down the slopes; but these advances and retreats are extremely slow.
The altitude of timber-line varies with locality. On Mount Orizaba, in Mexico, it is a little over thirteen thousand feet; in the San Juan Mountains, in Colorado, a little above twelve thousand; in the Sierras and the Rockies, between eleven thousand and thirteen thousand; in the Cascades and the Alps, about sixty-five hundred feet; on Mount Washington, at forty-five hundred feet. It is lower with increased distance from the Equator, and at last is only a stone's throw above sea-level, finally showing its line in the lowlands of the Farthest North. Among the trees that maintain the front ranks at timber-line are pines, spruces, firs, aspens, birches, and willows.
Many beautiful flowers are found at timber-line, along with bees, butterflies, birds, chipmunks, and foxes. Timber-line is a strangely interesting, arousing place. As I have said in "The Rocky Mountain Wonderland":—
The powerful impressions received at timber-line lead many visitors to return for a better acquaintance, and from each visit the visitor goes away more deeply impressed; for timber-line is not only novel and strange, it is touched with pathos and poetry and has a life-story that is heroic. Its scenes are among the most primeval, interesting, and thought-compelling to be found upon the globe.
2. ABOVE THE TIMBER-LINE
The treeless moorlands and the crags that fill the sky above the limits of tree-growth form an extensive mountain-top world all by itself, a realm of plateaus and sky prairies, which only a few have explored. These regions stand out like islands in the sky; they are singular treeless expanses above the surrounding forest sea.
ABOVE THE TIMBER-LINE IN THE ROCKY MOUNTAIN NATIONAL PARK
Long's Peak on extreme left