y through a
high waving plain to a rapid where the Missouri first leaves the Rocky
mountains, and here he encamped for the night.

In the meantime we had proceeded after breakfast one mile to a bend in
the left, opposite to which was the frame of a large lodge situated in
the prairie, constructed like that already mentioned above the Whitebear
islands, but only sixty feet in diameter: round it were the remains of
about eighty leathern lodges, all which seemed to have been built during
the last autumn; within the next fifteen and a quarter miles we passed
ten islands, on the last of which we encamped near the right shore,
having made twenty-three miles. The next morning,

Wednesday 17, we set out early, and at four miles distance joined
captain Lewis at foot of the rapids, and after breakfast began the
passage of them: some of the articles most liable to be injured by the
water were carried round. We then double manned the canoes, and with the
aid of the towing-line got them up without accident. For several miles
below the rapids the current of the Missouri becomes stronger as you
approach, and the spurs of the mountains advance towards the river,
which is deep and not more than seventy yards wide: at the rapids the
river is closely hemmed in on both sides by the hills, and foams for
half a mile over the rocks which obstruct its channel. The low grounds
are now not more than a few yards in width, but they furnish room for an
Indian road which winds under the hills on the north side of the river.
The general range of these hills is from southeast to northwest, and the
cliffs themselves are about eight hundred feet above the water, formed
almost entirely of a hard black granite, on which are scattered a few
dwarf pine and cedar trees. Immediately in the gap is a large rock four
hundred feet high, which on one side is washed by the Missouri, while on
its other sides a handsome little plain separates it from the
neighbouring mountains. It may be ascended with some difficulty nearly
to its summit, and affords a beautiful prospect of the plains below, in
which we could observe large herds of buffaloe. After ascending the
rapids for half a mile we came to a small island at the head of them,
which we called Pine island from a large pine tree at the lower end of
it, which is the first we have seen near the river for a great distance.
A mile beyond captain Lewis's camp we had a meridian altitude which gave
us the latitude of 46 d