of a large island called Bonhomme, or Goodman's
island. The country on both sides has the same character of prairies,
with no timber; with occasional lowlands covered with cottonwood, elm
and oak: our hunters had killed an elk and a beaver: the catfish too are
in great abundance.

September 2. It rained last night, and this morning we had a high wind
from the N.W. We went three miles to the lower part of an ancient
fortification on the south side, and passed the head of Bonhomme island,
which is large and well timbered: after this the wind became so violent,
attended by a cold rain, that we were compelled to land at four miles on
the northern side, under a high bluff of yellow clay, about one hundred
and ten feet in height. Our hunters supplied us with four elk; and we
had grapes and plums on the banks: we also saw the beargrass and rue,
on the side of the bluffs. At this place there are highlands on both
sides of the river which become more level at some distance back, and
contain but few streams of water. On the southern bank, during this day,
the grounds have not been so elevated. Captain Clarke crossed the river
to examine the remains of the fortification we had just passed.

[Illustration: Fortification]

This interesting object is on the south side of the Missouri, opposite
the upper extremity of Bonhomme island, and in a low level plain, the
hills being three miles from the river. It begins by a wall composed of
earth, rising immediately from the bank of the river and running in a
direct course S. 76 degrees, W. ninety six yards; the base of this wall
or mound is seventy-five feet, and its height about eight. It then
diverges in a course S. 84 degrees W. and continues at the same height
and depth to the distance of fifty-three yards, the angle being formed
by a sloping descent; at the junction of these two is an appearance of
a hornwork of the same height with the first angle: the same wall then
pursues a course N. 69 degrees W. for three hundred yards: near its
western extremity is an opening or gateway at right angles to the
wall, and projecting inwards; this gateway is defended by two nearly
semicircular walls placed before it, lower than the large walls; and
from the gateway there seems to have been a covered way communicating
with the interval between these two walls: westward of the gate, the
wall becomes much larger, being about one hundred and five feet at its
base, and twelve feet h