the distance of fifteen miles from the
Rattlesnake cliffs they reached a handsome open and level valley, where
the river divided into two nearly equal branches. The mountains over
which they passed were not very high, but are rugged and continue close
to the river side. The river, which before it enters the mountain was
rapid, rocky, very crooked, much divided by islands, and shallow, now
becomes more direct in its course as it is hemmed in by the hills, and
has not so many bends nor islands, but becomes more rapid and rocky,
and continues as shallow. On examining the two branches of the river it
was evident that neither of them was navigable further. The road forked
with the river; and captain Lewis therefore sent a man up each of them
for a short distance, in order that by comparing their respective
information he might be able to take that which seemed to have been most
used this spring. From their account he resolved to choose that which
led along the southwest branch of the river which was rather the smaller
of the two: he accordingly wrote a note to captain Clarke informing him
of the route, and recommending his staying with the party at the forks
till he should return: This he fixed on a dry willow pole at the forks
of the river, and then proceeded up the southwest branch; but after
going a mile and a half the road became scarcely distinguishable, and
the tracks of the horses which he had followed along the Jefferson were
no longer seen. Captain Lewis therefore returned to examine the other
road himself, and found that the horses had in fact passed along the
western or right fork which had the additional recommendation of being
larger than the other.

This road he concluded to take, and therefore sent back Drewyer to the
forks with a second letter to captain Clarke apprising him of the
change, and then proceeded on. The valley of the west fork through which
he now passed, bears a little to the north of west, and is confined
within the space of about a mile in width, by rough mountains and steep
cliffs of rock. At the distance of four and a half miles it opens into a
beautiful and extensive plain about ten miles long and five or six in
width: this is surrounded on all sides by higher rolling or waving
country, intersected by several little rivulets from the mountains, each
bordered by its wide meadows. The whole prospect is bounded by these
mountains, which nearly surround it, so as to form a beautiful cove
about