Page:An Illustrated History of the State of Oregon.djvu/19

 == HISTORY OF OREGON.==

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TOPOGRAPHY AND GEOLOGY.
GENERAL DESCRIPTION--COAST REGION-CASCADE RANGE-WILLAMETTE VALLEY-BLUE MOUNTAINS GREAT INTERIOR VALLEY-KLAMATH PLATEAU-VOLCANIC UPHEAVALS-VOLCANIC ROCKS GLACIAL ACTION-VOLCANOES-LAVA BEDS-FORMATION IN BLUE MOUNTAINS-LAVA PLAINS OF SNAKE RIVER-SCIENTIFIC STATEMENT-THE REGION OF THE COLUMBIA-FOSSIL BEDS.

TO present such a picture of the region of Oregon as will make it possible for the general reader to understand the country, it will be necessary first to give a brief description of its topography. Oregon, in general, topographically, is a series of deep valleys and lofty mountain ranges, extending northward and southward through the entire State. The exceptions to this statement are some lateral spurs of mountains that at a point or two project almost perpendicularly to the course of the main ranges, constituting the water-sheds between the streams that flow northward into the Columbia, or southward into the Sacramento, and the lakes of the great interior basin. From elevated volcanic plain lying along and near the 48° of latitude, and cutting the entire State from east to west, the drift of the valleys is northward to the great drain of the Columbia river, which is northern boundary of the State. This portion may be first considered, as it is much the larger and more valuable part of the State. Fixing our initial stake at the mouth of the Columbia river, the northwest corner of the State, we find first, closely pressing the Pacific coast, the Coast Range of mountains. This range has a width east and west generally of about thirty miles, and extends coastwise the entire width of the State, crowding its rocky feet everywhere into the spray of the ocean. It is densely timbered, hardly any pinnacle rising too high to produce the grandest firs, cedars and larch, with some higher summits. average altitude of this range may be put at about four or five thousand feet. It breaks gradually down eastward from its summit ridge into long slopes, separated by clear mountain streams, then into rounded foot-hills, crowned with oaks and firs, until the hills melt away into the verdure of the Willamette valley. From the summit of this range eastward, as the crow flies, a distance of one hundred and fifty miles, that of the great Cascade range is reached. Like the others this range cuts the State from north to south. It is much the higher, broader, and grander range. Its average width is not less than eighty miles, and its average altitude not below nine thousand feet. Crowning this mighty ridge, at intervals of fifty or more miles, great snowy summits, rising from three to five thousand feet above