Tuesday, April 29, 2008

The Grand Coulee

J.L. Ashlock

"The Coast" Magazine
Vol. X August 1905 No. 2

Imagine hewn in the earth's surface a colossal trough sixty miles in length, from one to three miles in width, with perpendicular walls rising to heights of from three hundred to eight hundred feet; the bottom strewn thickly with boulders in places, elsewhere, miniature Saharas of alkali and gravel, grassy meadows, clear freshwater lakes, and alkali ones bitter white; swamps, springs, creeks scattering pine trees, and somewhat in preponderance, sombre colored expanses of sage-brush and greasewood. This is the Grand Coulee. The surrounding country is level and prairie-like, within the last few years having become almost a solid wheat-field, and is known as the Big Bend country, which comprises all of Douglas, and part of Lincoln county, Washington. The region has been termed "the Big Bend" by reason of its being surrounded on three sides by the Columbia river, thus being enclosed in "the big bend" of the Columbia, of which stream the Grand Coulee is supposedly the prehistoric bed.

Ages ago, before the Grand Coulee had come into existence the climate of this section-far different in topography from the Big Bend of today, however was similar to the present climate of our Southern states, Florida in particular. The landscape comprised vast forests-now converted into the coal mines of northern Washington,-lakes, rivers, and mountains in comparison with which our mountains of today would be little more than ant-hills. How long these conditions existed we do not know, but we do know that ages ago, further remote than the imagination can reach, this landscape was buried from hundreds to thousands of feet deep by what is termed geologically, "The Basaltic Overflow." During this period rivers of molten basalt streamed from great cracks in the earth's surface, piling higher and higher, one layer overlapping another, till practically all of that section now comprising Eastern Washington, and extending southward into Oregon, was buried.

After the Basaltic Overflow the Columbia river cut its present channel. This work of time unreckonable was temporarily undone, however, by the Glacial Period. The glacial cap, as it crept southward, seems to have pushed before it mountain-like masses of gravel, which completely filled the channel of the Columbia, and the water, backing up, at length found an outlet to the south in what was then the Grand Coulee: not the great dry canyon of today, but a smaller depression which coursed in a southwesterly direction. The river, seeking the lowest level, naturally, followed this depression for some sixty miles, then seems to have spread out over what hi now called "the Crab Creek Desert;" thence, at various points, evidently joined its regular channel as it completes its curve around the Big Bend, starting westward toward the Pacific ocean; and during the time in which the river channel was blocked in this manner, the river cut the Grand Coulee across the Big Bend. As the glacial cap receded the river gradually resumed its former course, leaving the Coulee perfectly dry. At present the Columbia has not quite worn down to its former level, so immense were the quantities deposited by the glaciers.

Such, as nearly as can be read in the language of geology, was the origin of the Grand Coulee. Though its great, dry walls are now rotten and crumbling with age, in geological chronology, it came into existence but yesterday. For ages upon ages the prehistoric Big Bend was clothed in rich tropical verdure; its forests and plains ateem with antediluvian monsters whose petrified skeletons are now a wonder to the beholder; and in its lakes and rivers unreal Silurian reptiles plunged, and strange shelled things grew and decayed, all blending into the evolution of plant and animal to higher forms. Time inconceivable passed while the layers of basalt were cooling, having with the terrible force of Nature, blotted forever the rich landscape; and lapping thousands of times the length of written history into the past the Columbia began its work of channel-cutting, in which it first cleaved its way through solid basalt, forming the channel in which it flows today. Through solid basalt it forced its way during the Glacial Period, forming what is now the Grand Coulee. And then patiently commenced the work of re-excavation, at which it is engaged today, and will no more than have reached its former level when the great precipices of the Grand Coulee have rotted and crumbled away.

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