fs into the
open plains. Here they saw great numbers of the burrowing squirrel, also
some wolves, antelopes, muledeer, and vast herds of buffaloe. They soon
crossed a ridge considerably higher than the surrounding plains, and
from its top had a beautiful view of the Rocky mountains, which are now
completely covered with snow: their general course is from southeast to
the north of northwest, and they seem to consist of several ranges which
successively rise above each other till the most distant mingles with
the clouds. After travelling twelve miles they again met the river,
where there was a handsome plain of cottonwood; and although it was not
sunset, and they had only come twenty-seven miles, yet captain Lewis
felt weak from his late disorder, and therefore determined to go no
further that night. In the course of the day they killed a quantity of
game, and saw some signs of otter as well as beaver, and many tracks of
the brown bear: they also caught great quantities of the white fish
mentioned yesterday. With the broad-leafed cottonwood, which has formed
the principal timber of the Missouri, is here mixed another species
differing from the first only in the narrowness of its leaf and the
greater thickness of its bark. The leaf is long, oval, acutely pointed,
about two and a half or three inches long and from three quarters of an
inch to an inch in width; it is smooth and thick sometimes slightly
grooved or channeled with the margin a little serrate, the upper disk of
a common, the lower of a whitish green. This species seems to be
preferred by the beaver to the broad-leaved, probably because the former
affords a deeper and softer bark.

Thursday 13. They left their encampment at sunrise, and ascending the
river hills went for six miles in a course generally southwest, over a
country which though more waving than that of yesterday may still be
considered level. At the extremity of this course they overlooked a most
beautiful plain, where were infinitely more buffaloe than we had ever
before seen at a single view. To the southwest arose from the plain two
mountains of a singular appearance and more like ramparts of high
fortifications than works of nature. They are square figures with sides
rising perpendicularly to the height of two hundred and fifty feet,
formed of yellow clay, and the tops seemed to be level plains. Finding
that the river here bore considerably to the south, and fearful of
passing the falls before re