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. 2, Pt. 2

HUMBOLDT RIVER VALLEY.
the mountain chains, which rapidly succeed each. other, apparently rising from a common plain,
overlap, and it is impossible to trace the course of the river without reference to maps. A
few streams are seen descending towards it from the mountains in the immediate vicinity, but
few of them, however, reach it, their waters being absorbed by the light soil of its valley.
The whole landscape, except just above us, presents a sombre and even barren aspect, sage
being the prevailing plant.
The main mountain depression of this pass exceeds two miles in width to the east, but at the
head of the ravine, to the west, it does not exceed a half mile in its narrowest part, including
the ravine which is only 100 or 150 feet wide. Snow covers the high peaks above it, and a few
drifts extend in the ravines down to the level of its summit. The rocks are granite, quartz
in masses, blue limestone, and slate, altered by igneous action. In approaching the pass from
the east, advantage can be taken of the mountain spur which extends into the plain from its
northern edge to the right of our path, to enter it and pass its summit by a longer and easier
grade even than that given in the accompanying profile, which indicates the natural grade by
which we ascended it; and in descending to the west, its width and the character of the mountain sides are such that some advantage can be taken of them to effect the descent by a line following the hills on the north side of the pass, but this advantage will be confined chiefly to that
portion below the rocky ravine.
The ascending grades from our morning camp, as indicated by our barometers, are, for 7.65
miles, to. the crossing of Franklin river, 58.10 feet per mile, and thence to the summit of the
pass, 2.89 miles, 25.10 feet per mile, the altitude of the summit being 6,579 feet above the sea;
and the descending grade to the west, for the first 0.80 of a mile, 78.30 to the mile; and thence
to the base of the bald butte, 8.36 miles, 96.70 feet to the mile. Below this point we enter
the valley of the Humboldt river.between its north and south forks, their junction being, by the
course of the creek descending from this pass and the north branch of the river, thirty-five
miles distant, with an average descent of 28.50 feet per mile.*
The valley of the Humboldt river having been explored by Colonel Fremont, and so favorably
represented for the line of a railroad, no further examination of it was deemed necessary and
being obliged to proceed sixty miles south to cross the Humboldt mountains with our wagons, I
determined to proceed west from that pass across the Basin by a route not before explored,
returning to the valley of the Humboldt near the point at which it is proposed for the railroad
to leave it in its western course. The 23d of May having been spent in examining the pass
described, we resumed our journey on the following morning.
*The Humboldt river "rises in two streams in mountains west of the Great Salt lake, which unite, after some fifty miles,
and bears westwardly along the northern side of the basin. -- t- * The mountains in which it rises are round and handsome
in their outline, capped with snow the greater part of the year, well clothed with grass and wood, and abundant in water. The
stream is a narrow line, without affluents, losing by absorption and evaporation as it goes, and terminating in a marshy lake,
with low shores, fiinged with bulrushes, and whitened with saline incrustations. It has a moderate current, is from two to
six feet deep in the dry season, and probably not fordable anywhere below the junction of the forks duiing the time of melting
snows, when both lake and river are considerably enlarged. The country through which it passes (except its immediate valley)
is a dry sandy plain, without grass, wood, or arable soil; from about 4,7()0 feet (at the forks) to 4,200 feet (at the lake) above
the level of the sea, winding atmong broken ranges of mountains, and varying from a few miles to twenty in width. Its own
immediate valley is a rich alluvion, beautifully covered with blue-grass, herd-grass, clover, and other nutritious grasses, and
its course is marked through the plain by a line of willow, * i - serving for fuel.
"This river possesses qualities which, in the progress of events, may give it both value and fame. It lies on the line of travel
to California and Oregon, and is the best route now known through the Great Basin, and the one travelled by emigrants. Its
direction, mostly east and west, is the right course for that travel. It furnishes a level, unobstructed way for nearly three
hundred miles, and a continuous supply of the indispensable articles of wood, water, and grass."-Geographical Memoir
addressed to the Senate of the United States in 1848, by Colonel Fremont-June, 1848.
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