RIVERS & LAKES.—BOOK I. 
47 
and In these, sandbars impede the navigation in low water : at 
these times the river is reduced in places to less than a fourth 
of its usual breadth, between sand-bars which advance into it, 
and a high bank. But when the channel is full, the river even at 
the Mandans, appeared to me not less broad or majestic, than 
does the Mississippi at New Orleans. 
The cataracts of the Missouri, from every description, are, 
next to those of Niagara, the most stupendous in the world. The 
descent, in the distance of eighteen miles, according to the esti¬ 
mation of Lewis and Clark, is 362 feet 9 inches. 
The first great pitch 98 feet 
— second - 19 — 
—- third - 47 — 8 inches 
— fourth - 26 — 
besides a number of smaller ones. The width of the river is 
about three hundred and fifty yards. 
The whole extent of navigation of this riyer which has no 
other cataract or considerable impediment, from tire highest 
point on Jefferson river., the largest of the three forks, to its en¬ 
trance into the Mississippi, is three thousand and ninety-six 
miles; no other tributary stream in the world possesses such a 
navigation. 
ARKANSAS. 
The Arkansas, next to the Missouri, is the most consid¬ 
erable tributary of the Mississippi. In length it is nearly two 
thousand five hundred miles, and navigable at proper seasons 
nearly the whole distance. In many places its channel is 
broad and shallow, at least above the rapids, so as to render na¬ 
vigation almost impracticable. Until eight or nine hundred 
miles from its mouth, it receives no considerable streams, owing 
to the vicinity of the waters of the Missouri, of the Kansas, See , 
on the one side, and those of Red river on the other. The chief- 
rivers which fall into it, are the Verdigris, the Negracka, Cana¬ 
dian river, Grand river, Sec. Several are remarkable for being 
strongly impregnated with salt; the Arkansas itself, at. certain 
seasons is said to be brackish. 
