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A snowstorm at timber-line.-The snowfall along the continental divide in Colorado is one of the heaviest of the country. In the immediate vicinity of Longs Peak it feeds the Grand River on the west and tributaries of the Platte on the east. "Eternal snow" lies all along the Front Range and from its border there flows a sheet of icy water during the summer days

The Wars of the Wind at Timber-line




Illustrations from photographs by the Author


OR ages the high, dry, winter wind had blown out of the west across the Continental Divide. Down the eastern slope these winds swept roaring against the ragged, battered upper ranks of the forest at timber-line. At one place in the Rocky Mountain National Park they came down across a wide treeless moorland between two lateral moraines of huge size. They dashed so fiercely against the forest front that the aggressive trees had never been allowed to do more than peep over the edge of the inclined moor. Again and again an adventurous seedling had dared the treeless space only to be blown to pieces before it could get a good roothold.

One day far up a mountain-side a

cliff crashed and fell. The ice had at last wedged it off. It plunged and rolled down a steep slope with great leaps, and went to pieces. A few of the pieces tumbled far out on this moor. The largest stone formed a small windbreak a few hundred feet in advance of the forest's wind-battered edge.

In due time a few daring seeds sought to start a tree outpost in this shelter. They succeeded. In a close cluster they grew up. When they rose. above the upper surface of the rock the terrific winter wind cut them off with sand blasts and the cutting edges of glassy sleet. New trees from time to time found a foothold to the leeward of the stone's pioneer tree cluster. Thus a line of trees gradually extended in a


long wind-battered row, thick as hedge, to the front ranks of the forest. The wind did not allow a tree to start or a limb to extend beyond the sheltered edges of the stone.

The timber-line of which this windrow was a part stretches along the eastern or Atlantic slope of the high Continental Divide for hundreds of miles. The Engelmann spruce and the Arctic willow represent the tree growth in the moister places, while it falls to the lot of some variety of the limber pine to maintain the forest front on the dry wind slopes and rock ridges.

Timber-line, like the shore line of the sea, bends and curves. Here a mountain-side cañon causes it to sweep back like a bay of the sea, and there it thrusts itself out around a peninsulalike headland. In places the topography causes it to extend for a mile or more in a straight line. Next it comes to an end upon an out-cropping of barren rock which offers it no soil; and in places a drift of "eternal snow" holds it at bay; while on slopes and ridges the dry and devitalizing winds say, "Thus far and no farther."

The winds and gales that strike and beat and break against the front ranks of the forest, roar as intensely as a storming sea upon the shore, and with all its terrible eloquence.

Wind is the strongest factor in the life of these timber-line trees. This is shown in their attitudes and shapes. Standing trees are tilted toward the east, the vinelike, crawling trees are headed east, and those standing with banners and pennants of long, tattered limbs and foliage, extend their arms only toward the east. All proclaim, "Out of the west come the forces that direct us." At timber-line, wind, the sculptor, has carved for himself a thousand graphic tree statues that proclaim his presence and his power.

The stone on the moor continued to shelter the windrow at timber-line. Each winter around the stone the vio

lent winds raged, and pounded it almost incessantly. During the summer months the wind rarely blew. Then brilliant flowers stood thickly in a green and snowdrift-dotted Alpine But with the coming of autumn the wind again came pouring out of the west across the peak-broken heights. Through the long winter it commonly blew from the same quarter.


As it poured around the stormward corners of the stone, the wind gradually blew the earth away. Then along the stormward front of the stone it connected these corner erosions with a channel. Finally it began to undermine this immovable wind-defying piece of granite. Each spring and summer the water from the winter snows and from the rains carried forward the eroding, undermining work of the wind.

Occasionally an accident came to a tree or two in the windrow and a slight opening was left, between the grizzled edges of which a man might squeeze through. One day a bowlder rolled down and smashed a larger opening. But most of the trees in this long, narrow hedge interlaced still more closely with new limbs. The wind did not allow them to extend their tops upward or their arms outward beyond the line determined and sheltered by the stone. Each winter the hundreds of tiny adventurous twigs that had during summer grown beyond the side or the top lines were clipped off by the wind.

A long, long time the stone remained. Upon it many a white ptarmigan alighted; upon it, too, the crested noisy jay, the quiet camp-bird, and the curious magpie often sat to look upon the scene. Around it lived the bighorn sheep. Beside it a grizzly once dug for a chipmunk.

On the wide moor here and there a partly embedded rock fragment sheltered a tiny persistent tree. Here and there a bowlder that had rolled down from one of the moraines sheltered



The timber-line, which is one of the most marked boundaries of plant zonation, sweeps in a sinuous course along the higher ranges of the Rockies, now ascending a After this manner the Arctic-Alpine and Hudsonian, or forest, zones protected gully, now driven down the mountain's side from a wind-swept lane or rocky prominence. In the upper mountain forest of northern Colorado the Engelmann spruce and limber pine chiefly abound, while above the tree limit lies a rocky tundra with its lichens, low willows, and herbs. Here the ptarmigan, pipits, and finches find their breeding grounds in spring, lap past each other for vertical distances as great as a thousand feet. Lichens are the most important element in breaking up the rocks to form the minimum of soil in which mosses, grasses and building their homes among the rock débris. shrubs may gain a foothold


somewhat larger growing trees. A pile of débris that a landslide had brought down sheltered a grove almost twelve feet high.

Immovable the great stone lay on the moor. Dust and trash accumulated beneath the trees in its shelter, as under any hedge, and formed a barrier which blocked the water coming down the slope of the moraine. This cut a small channel alongside the tree row. This water joined the wearing, undermining forces of the wind that ever worked beneath the stormward foundation of the protecting stone.

Immovable the stone continued to lie through the wonder summers amid Alpine flowers, and through the roaring windy winters, while invisible chemistry tinted it with many hues and the lichens came to color it. But at last the wash of water and the sweep of winds dug a great hole in front and beneath the stone. Early one summer as the frost was vanishing from the soggy earth the stone settled forward and rolled over into the hole on its side, leaving the windrow of trees to the winds. This was only a few years ago, but today those trees are only a mem


Most of the forest front is without a windbreak. While ridges, landslide débris, and bowlders here and there afford protection, the main timber-line breasts the wind unsheltered. If one follows along this strange boundary line, the timber-line, he will see in some places trees which have been struck by lightning, others mowed by snowslides and in places crushed, and in still other places trees protected by bowlders or landslides that have come down from the treeless heights above. Trees that have grown up to the leeward of a shelter are quickly trimmed and markedly changed shortly after the sheltering barrier is removed.

A tree may be forced out of plumb by prevailing winds and then be caught

by heavy snow and crushed down and held so long that it never regains its upright position. There are acres of trees prostrate, chiefly from the effect of high winds, but perhaps incidentally from the weight of winter snow. A combination of wind and snow causes many a tree, at a foot or less above the earth, to abandon the growth of its top and give all of its energy in sending out and maintaining long limbs which radiate in all directions. Many of the long, storm-tempered limbs are nearly as tough as steel. The smaller limbs may be knotted without breaking.

In other places trees grow along the ground to the leeward with a few flattened limbs streaming out parallel to the top. The few scattered erect ones possess limbs on only the leeward quarter. Limbs on the stormward side have never been allowed to grow. Many trees thus are standing, worn away to the heart on the stormward side, the naked bones showing, while on the leeward there is the green bark and long out-streaming limbs.

Many of these dwarfed ancient looking little trees are not two feet high. Yet they are two and three centuries old and look as old as the mountains. Some are two or three feet in diameter and less than eight feet high. Numbers of trees, although at least a century old, are but small grizzled shrubs. In places a number of these may be growing together in a beautiful wild-flower garden composed chiefly of dwarfed flowers,-flowers with stalk and bloom perfectly formed but less than one inch in height. Like the trees themselves, many of these dwarfed plants have a strange and extensive root system, while others, like many of the trees, are growing on only the leeward quarter.

Areas of a "block" or more are covered with low matted growths as smooth and unbroken as the trimmed surface of a hedge. They are clipped off almost as level as a lawn, with the



Dwarfed, ancient looking little trees, matted together behind a sheltering rock, maintain themselves far beyond the tree limit. Their tops are clipped off as in a trimmed
hedge, for any adventurous twig that reaches too far upward during the summer is certain to be dried out and killed by the winter winds. The work of the wind is not al-
together destructive, however, for it carries dust from the upper plateau to the nooks and corners of the glacier valleys to serve as soil where the meadow and, later, the
forest can gain a foothold for advance in the never-ending struggle up the granite slopes


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