166 TOPOGRAPHY OF ROUTE FROM THE MISSISSIPPI TO THE COLUMBIA. 
lages, and one or two small lakes. Medicine or Sun river forms a boundary between the mount- 
ains and the prairies, and exhibits a mixed character of bluffy intervale, open valley, and mount- 
ain rapid; having an easterly course about eighty miles in length, and joining the Missouri above 
the Great Falls. It rises in a few small branches, where the dividing ridge of the Rocky mount- 
ains begins to break down into spurs and valleys towards the Missouri; and when the traveller 
has crossed this river, he perceives that he is quitting the great prairies and entering the mountain 
region. 
Of the twelve hundred miles travelled distance from St. Paul of prairie country between the 
upper Mississippi and the Rocky mountains examined by the several parties of the expedition, 
the finest section is that from the Mississippi to the Shayenne, embracing some of the rivers on 
the western slope of the Mississippi basin, as the Sauk, the Watab, Little Falls creek, &c., and 
the summits between these waters and the various affluents of the Red river, the Minnesota or St. 
Peter’s river, and the Missouri. The greater part of this section, as noticed in the commence- 
ment of this report, is considered by parties of approved experience to resemble the most favored 
districts of Ohio and Wisconsin; and there can be no question of its great capacity and resources, 
even while confining the examination to its surface only. 
Towards the Missouri plateau, and northwards over Mouse river to the Assiniboin, the country 
is comparatively of inferior character, though abounding, probably, in greater quantity and variety 
of game; which, with its red hunters, is ever found retiring before the pioneers of the white 
man’s progress. From Fort Union westward the aspect of the country is almost uniformly wild 
and barren; and this, not because the country becomes so much more inferior, as for reasons 
referable to uniformity of elevation and dryness of the climate, which apply more or less to all 
the great plains north and south between the Mississippi and the Rocky mountains. The great 
mountain ranges near either coast of the continent exclude the fertilizing ocean vapors from the 
far interior; and even the slight degree of moisture which the waters of the high prairies afford 
to the atmosphere is floated off to the mountains before it is precipitated in rain; hence, proba- 
bly, the total absence of timber, except in the river bottoms, and the thinness of the grass, which, 
as well as the earth itself, in early summer becomes parched and browned under cloudless skies 
and scorching suns. 
Along with such general reasons must be mentioned the more particular one, of the frequent 
prairie fires which mark the tracks of Indian tribes and half-breed hunters. The prairie is often 
fired as a signal to distant parties, and not unfrequently for very trifling purposes; and, if left 
unquenched, will sweep over the country until stopped by a river, and leave an appearance of 
utter desolation. The eye grows weary travelling over the naked outlines of the successive 
plateaux, which, divided and bounded by the various rivers noticed, form but subdivisions of the 
great tract of country stretching from Missouri and Milk rivers on the south, to the Saskachawan 
on the north—this tract itself but a subdivision of the Great Plains—an extent embracing every 
variety of surface, from large and level plains to abrupt bluffs and ranges of summit hills that 
might be considered mountains. It is difficult to convey an adequate idea of the immensity of 
these dreary solitudes. Let it be remembered that a few minutes’ reading embraces sections which 
require tedious weeks to traverse; and that even travelling over and observing them with the 
patient labor of months, leaves but a feeling of their vastness, which bafHles the effort to express 
it. The impressive silence of succeeding days is broken at rare intervals by the crack of some 
stray hunter’s rifle, or perchance by the yell of painted warriors on a foray ; but when the 
twilight wanes over the peaceful camp, when the evening meal is over, and the incidents of the 
march are recounted, then the “drowsy ear of night” is roused to listen to the prolonged and 
melancholy cry of prowling wolves. 
The verdure of these regions, though growing thinner and comparatively inferior as we go 
westward, never entirely disappears anywhere, if the faces of the steep bluffs upon the rivers be 
excepted ; artemisia and small cacti are occasionally met with, but not in great quantities, and 
