tance of eight miles is a mountain, which
from its appearance we shall call Fort Mountain. It is situated in the
level plain, and forms nearly a square, each side of which is a mile in
extent. These sides, which are composed of a yellow clay with no mixture
of rock or stone whatever, rise perpendicularly to the height of three
hundred feet, where the top becomes a level plain covered, as captain
Lewis now observed, with a tolerably fertile mould two feet thick, on
which was a coat of grass similar to that of the plain below: it has the
appearance of being perfectly inaccessible, and although the mounds near
the falls somewhat resemble it, yet none of them are so large.

CHAPTER XII.

The party embark on board the canoes--Description of Smith's
river--Character of the country, &c.--Dearborne's river
described--Captain Clarke precedes the party for the purpose of
discovering the Indians of the Rocky mountains--Magnificent rocky
appearances on the borders of the river denominated the Gates of
the Rocky mountains--Captain Clarke arrives at the three forks of
the Missouri without overtaking the Indians--The party arrive at
the three forks, of which a particular and interesting description
is given.

Monday, July 15. We rose early, embarked all our baggage on board the
canoes, which though light in number are still heavily loaded, and at
ten o'clock set out on our journey. At the distance of three miles we
passed an island, just above which is a small creek coming in from the
left, which we called Fort Mountain creek, the channel of which is ten
yards wide but now perfectly dry. At six miles we came to an island
opposite to a bend towards the north side; and reached at seven and a
half miles the lower point of a woodland at the entrance of a beautiful
river, which in honour of the secretary of the navy we called Smith's
river. This stream falls into a bend on the south side of the Missouri,
and is eighty yards wide. As far as we could discern its course it wound
through a charming valley towards the southeast, in which many herds of
buffaloe were feeding, till at the distance of twenty five miles it
entered the Rocky mountains, and was lost from our view. After dining
near this place we proceeded on four and three quarter miles to the head
of an island; four and a quarter miles beyond which is a second island
on the left; three and a quarte