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

PARTIAL RESULTS OF EXPLORATION.
There will be no difficulty as to water. It will be deficient at points on the broad plateau be
tween the Milk and Missouri rivers, but by aqueducts it can easily be supplied. The lakes on
the Grand Couteau will also furnish the means of supplying any deficiency from the Grand
Couteau to a point south of the Miniwakan lake. But our- observations go to show that there
need be little apprehension of a'deficiency here.' Oni.the'Great Plain of the.Columbia, I apprehend no deficiency in the supply of water; the whole country' abounds in lakes and small
streams.
Our observations and inquiries go to show that the average depth of snow east of the mountains to the Missouri does not exceed one foot. Two feet is an extraordinary depth, and the most
experienced voyageurs in that country have never been detained a single day in travelling by
snow. The most they have been compelled to do was to lie by till the storm was over.
In the Rocky mountains, and on the line of Clark's fork, the snow is hardly ever deep enough
to prevent the Indians travelling with their families on horseback all through the winter: one
foot is a common depth, and three feet' is a very extraordinary depth, in the Rocky mountains.
Last winter the average on the. several'.,passes was less than one foot. The winter before the
winter of greatest snow for many!years, as shown by the unprecedented rise of the rivers in the
following spring-the'depth.;was- three feet.
On the Plain of the Colum'mrbia, in the lower Columbia valley, and on the route thence to the
Sound, the snow is inconsiderable.
On the route of the Yakima and the Snoqualme Pass, there is but little snow for some forty
miles eastward from the Sound, and for more than a hundred miles up the Yakima valley. On
the pass itself, there was, the last winter, on the 20th January, six feet of light snow for some
six miles. The depth, I am of opinion, did not much increase subsequently; but to test the question fully, further observations ought to be made.
For more full information in reference to the forest growths, supply of sleepers, and buildingmaterials for the road, and for the supply of water, I will respectfully refer you to Chapters V
and X[I of my report. Chapter V treats of the section east of the Rocky mountains, and Chapter XII of the section west. For the depth of snow, I will refer you to Chapter XIV, and to subreports I 35, I 36, I 37, and I 38.
The observations for heights having been lost, the discussion of the several altitudes cannot be
made till they are recovered; and for longitudes, the only dependence at this time, and before
further observations are made, will be to adjust the odometer line in connexion with the latitudes
between Nicollet's Lake Jessie and Wilkes's Wallah-Wallah on a projection, and ascertain a particular longitude by protraction; I am confident the result will be good.
The general map indicates lines to be examined, and for full information I will respectfully
refer you to Chapter XVIII of my report. I will, however, give the following condensed statement of examinations which I will recommend to be made:
1. More detailed examinations of the line of the lower Columbia and of the line of the Snoqualme Pass, to determine which is most practicable.
2. Careful examinations of Lewis and Clark's, Cadotte's, and the Northern Little Blackfoot
Passes, and their several approaches, to determine as to which is most practicable. If Lewis
and Clark's or Cadotte's Pass be preferred to the Northern Little Blackfoot, examinations to be
made to determine the practicability of passing directly firom the Blackfoot trail to Clark's fork.
This proving impracticable, or the Northern Little Blackfoot Pass proving preferable, then a
careful comparative survey to be made of the line of the Bitter Root and the line of the Jocko.
More careful observations of the southern portion of Clark's fork to be made, to determine
whether the road shall pass to the Spokane from the western or the eastern side of the Pend
d'Oreille lake.
Examinations to be made to determine the practicability 0f connecting the Rocky mountain
passes with Council Bluffs through the Black ilills, and also to determinme whether these passes
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