CHAPTER III. 
General Description of Region Examined, and Results Accomplished.—General Salubrity 
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 Yellow¬ 
stone, 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 ex¬ 
cellent 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 spurs 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 de¬ 
grees 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 lon¬ 
gitude 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 west¬ 
ward; the easy character and the low elevation of the passes of the Rocky mountains; the prac¬ 
ticable character of the passes in the Coeur d’Alene and Cascade mountains, and its connexion 
with the great natural water communication across the continent of the Missouri and Columbia 
rivers. 
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