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TOPOGRAPHY OF ROUTE FROM THE MISSISSIPPI TO THE COLUMBIA. 165 
the same course) of the junction of the Marias and Missouri rivers. In the space embraced by 
the Missouri and Milk rivers are two distinct groups of mountains, the first that are seen on the 
route—the Bear’s Paw group filling the western end of the enclosed section; the Little Rocky 
mountains occupying the centre, besides groups of prairie hills. ‘These mountains abound in 
varieties of pine timber, and practical roadways are reported; but Milk river, from its unex- 
pected directness from its mouth to the turning-point north of Bear’s Paw mountains, and from 
its firm and level though narrow intervale, is emphatically the natural highway westward through 
this section of the prairies. ‘The mountains it embraces, with the Missouri, will be fully developed 
by the explorations of Dr. Evans and Lieut. Grover, reports of which have not yet been received. 
From the route on the fork of the Milk river, along the western base of the Bear’s Paw mount- 
ains, an isolated mountain group (the Three Buttes, already mentioned) is seen distinctly for 
several days, to the northwest, at a distance of seventy miles, as ascertained by the intersection 
of frequent compass observations from the line of the odometer survey. The position of every 
prominent hill was accurately fixed in this manner, and served to give greater precision to the 
several lines of exploration which passed them with estimated distances. On approaching the 
mountains, it is surprising how clearly the most distant objects can be distinguished. The atmo- 
sphere becomes so transparent, that it is only the curvature of the earth’s surface that limits the 
view from the highest points; the crevices and minute features of distant hills appear so well 
defined, that all previous ideas of distance are disturbed; and amusing mistakes are made by par- 
ties intent on exploring some interesting feature, apparently only a few miles off, but which, when 
tried, turns out to be a fair day’s journey. 
The Three Buttes are well wooded with pine, and watered by small streams flowing to the 
different rivers of the prairies. Their greatest altitude above the plain is about three thousand 
three hundred feet; and from the summit the view is highly illustrative of the surrounding 
country, embracing every prominent object within a hundred miles. On the north, about ninety 
miles, stands Cypress mountain, far over the 49th parallel; on the east and northeast, the inter- 
minable prairies; on the southeast, the Bear’s Paw mountains; on the south, the various detached 
groups of mountains beyond the Missouri; and on the west, about ninety miles, is seen the 
dividing ridge of the Rocky mountains, which is itself the boundary of the prairies in this direc- 
tion, having none of the broken spurs which present an easier access farther south. The inter- 
vening regions present but few objects to arrest the eye; they are intersected by the various rivers 
and their branches, which are hidden, even with their timber, in the deep intervales common to 
them all. It may suffice to say that there are probably few other places in the world where 
twenty thousand square miles can be embraced in the view from a single point. 
Marias river is the first of the prairie streams having its sources at the base of the mountains. 
Its general course is southeast by east, and its length about one hundred and thirty miles. It 
resembles the Missouri in its character of intervale and tall steep bluffs, which, with its fringe of 
cotton-wood, disappears altogether near its sources. Within a mile of its mouth it receives the 
Teton or Tansey river, a smaller stream of similar character, rising also at the base of the 
mountains. These rivers appear to have worn quite down through the soft formations of the 
prairies, and flow in clear and rapid streams on the underlying indurated strata. Marias river is 
reported by competent judges to be capable of improvement, so as to be navigable by light 
steamers for fifty miles of its length. 
From the crossing of Marias river near its mouth to Fort Benton, it is about eleven or twelve 
miles, southwest. About half that way the Teton and Missouri flow so near each other that the 
traveller perceives their waters from the dividing bluff, apparently not more than one hundred 
yards apart, but really much more, of course. About fifiy miles more, in the same course from 
Fort Benton, reaches Sun river, eight or nine miles from its mouth. This distance is through the 
high prairie between the Missouri and Teton, presenting the usual plateau character of bluffs and 
coulées, and containing the most considerable field of prickly pear that was seen; some dog vil- 
