HISTORY OF OREGON.
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CHAPTER I.
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
