Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean: Vol. 1, Pt. 2

CHAPTER III.
General Description of Region Examined, and Results Accomplished. General Salabrty
of the Region.
The country thus occupied, or to be occupied, may be described as follows: It lies between
the great lakes and Puget sound, the forty-ninth parallel and the emigrant route of the South
Pass. In it are four great rivers-the Mississippi and the Red river of the North, flowing into the
Gulf of Mexico and Hudson's bay; the Missouri and Columbia rivers, flowing eastward and
westward from the Rocky mountains in opposite directions.
There are three mountain ranges, running in a general direction north and south-the Rocky,
Coeur d'Alene, and Cascade mountains. The four rivers are more than powerful auxiliaries as
lines of communication in building the road and advancing settlements, affording in their course
large tracts of arable and pasture land and inexhaustible supplies of lumber and stone. They
have essentially modified the climate. The Mississippi and the Red river of the North, with their
several tributaries interlocking each other, nearly all heavily timbered, make the eastern portion
of the field one of inexhaustible fertility, and have great natural advantages for bringing supplies
and productions of all kinds to market. The Missouri river has turned the formidable chain of the
Black Hills and Wind River mountains, and with its southern tributaries, especially the Yellowstone, presents a rich and inviting country at the base and into the valleys of the mountains.
The Columbia has found its way through the Coeur d'Alene and Cascade chains, affording excellent passes, and the tributaries of the two rivers interlocking in the Rocky mountains have
broken it into spurs and valleys, affording several practicable passes, and with a tunnel admitting
the passage of a road at an elevation of about five thousand feet.
In the region of the South Pass the Rocky mountain range extends from near Fort Laramie to
the valley of the Salt lake, through nearly seven degrees of longitude, or a distance of about three
hundred miles, at an elevation of, from 4,519 feet (Fort Laramie) to 7,400 feet (South Pass,) and
from.4,222 feet (Great Salt lake) to 8,400 feet (Wahsatch mountains,) above the sea; and the
whole system of ranges to the Pacific extends through seventeen degrees. Northward, none of
the subsidiary purs that branch to the eastward cross the Missouri and Yellowstone, and the
main chain deflects considerably to the westward, till, in the region extending from the sources of
the Missouri to the headwaters of Sun river, the system of ranges extends only through nine degrees of longitude, of which three to four degrees are occupied by the prairie region of the Great
Plain of the Columbia, and in the several passes the greatest elevation is about 6,300 feet, and
the length of the route where the elevation exceeds that of Fort Laramie and the Great Salt lake,
is fifty-six miles. Crossing the Yellowstone and Missouri, the whole country eastward to the
Mississippi is a prairie region. Puget sound is in the same longitude as San Francisco, and a
railroad through the South Pass to San Francisco or Puget sound must, without making any
allowance for the Great Plain of the Columbia, pass over a mountain region eight degrees in longitude greater than by the route north of the Missouri and Yellowstone.
Thus the distinctive character of the route is the great extension of the prairie region westward; the easy character and the low elevation of the passes of the Rocky mountains; the practicable character of the passes in the Cceur d'Alene and Cascade mountains, and its connexion
with the reat natural water communication across the continent of the Missouri and Columbia
rivers.
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