The most prominent features of this great river, which is fed by so many
streams, having their sources in a great variety of soils and climates,
are its wonderful falls, rapids and cascades, the following connected
view of which is abstracted from the very accurate draught and survey
made by Captain Clarke.
This river is nine hundred feet wide at the point where it receives the
waters of Medicine river, which is four hundred and one feet in width.
The united current continues five thousand, four hundred and twelve
feet, somewhat more than a mile, to a small rapid on the north side,
from which it gradually widens to four thousand, two hundred feet, and
at the distance of nine thousand and forty-two feet, (nearly a mile and
three-fourths,) reaches the head of the rapids, narrowing as it
approaches them. Here the hills on the north, which had withdrawn from
the bank, closely border the river, which, for the space of a mile,
makes its way over the rocks with a descent of thirty feet: in this
course the current is contracted to sixteen hundred and forty feet, and,
after throwing itself over a small pitch of five feet, forms a beautiful
cascade of twenty-six feet, five inches; this does not, however, fall
quite perpendicularly, being stopped by a part of the rock, which
projects at about one-third of the distance. After descending this fall,
and passing the Cotton-wood island, on which the eagle has fixed its
nest, the river goes on for eight thousand, seven hundred and
seventy-eight feet, (more than a mile and a half,) over rapids and
little falls, the estimated descent of which is thirteen feet six
inches, till it is joined by a large fountain boiling up underneath the
rocks near the edge of the river, and falling into it with a cascade of
eight feet. It is of the most perfect clearness, and rather of a bluish
cast; and even after falling into the Missouri it preserves its color
for half a mile. From this fountain the river descends with increased
rapidity for the distance of thirty-five hundred and thirty-one feet,
during which the estimated descent is five feet: from this, for a
distance of twenty-two hundred and twenty-seven feet, the river descends
fourteen feet seven inches, including a perpendicular fall of six feet
seven inches. The river has now become pressed into a space of fourteen
hundred and nineteen feet, and here forms a grand cataract, by falling
over a plain rock, the whole distance across the river, to the depth of
forty-seven feet, eight inches: after recovering itself, the Missouri
then proceeds with an estimated descent of three feet, till at the
distance of sixteen hundred and eighty-three feet it again is
precipitated down the crooked falls, nineteen feet perpendicularly;
below this at the mouth of a deep ravine, is a fall of five feet, after
which, for the distance of sixteen thousand and five feet, (upward of
three miles,) the descent is much more gradual, not being more than ten
feet, and then succeeds a handsome level plain for the space of
twenty-nine hundred and thirty-seven feet, (more than half a mile,) with
a computed descent of three feet, making a bend toward the north. Thence
it descends, during seventy-nine hundred and twenty feet, about eighteen
feet and a half, when it makes a perpendicular fall of two feet, which
is fourteen hundred and eighty-five feet beyond the great cataract, in
approaching which it descends thirteen feet, within a distance of about
six hundred feet, and gathering strength from its confined channel,
which is only eight hundred and forty feet wide, rushes over the fall to
the depth of eighty-seven feet and three-quarters of an inch. After
raging among the rocks, and losing itself in foam, it is compressed
immediately into a bed of two hundred and seventy-nine feet in width; it
continues for fifty-six hundred and ten feet to the entrance of a run or
deep ravine, where there is a fall of three feet, which, joined to the
decline of the river during that course, makes the descent six feet. As
it goes on, the descent within the next thirty-nine hundred and sixty
feet is only four feet; from this, passing a run or deep ravine, the
descent for sixteen hundred feet is thirteen feet: within thirty-nine
hundred and sixty feet, is a second descent of eighteen feet; thence
twenty-six hundred and forty feet further, is a descent of six feet;
after which, to the mouth of Portage creek, a distance of forty-six
hundred and twenty feet, the descent is ten feet. From this survey and
estimate it results that the river experiences a descent of three
hundred and fifty-two feet in the course of fifteen or sixteen miles,
from the commencement of the rapids, to the mouth of Portage creek,
exclusive of almost impassable rapids which extend for a mile below its
entrance.