162 TOPOGRAPHY OF ROUTE FROM THE MISSISSIPPI TO THE COLUMBIA. 



the small detached parties, though without having this circumstance especially in view; and it 

 is impossible to suppose that such an insignificant water-course should have a length and volume 

 necessary to penetrate the formidable plateau of the Missouri. 



This misconception is stated at length to show the uncertain character of information supplied 

 by guides, who, however well acquainted with the country in which they hunt and live, are rarely 

 capable of expressing themselves with reference to any subject foreign to their own pursuits, 

 besides bein&amp;lt;* always liable to be misunderstood from the contusion of tongues which is usually 

 heard on the outskirts of civilization. It is but justice here to say that a signal exception to 

 these remarks was ever presented in the intelligent and exact description of our French guide, Mr. 

 La Bombard, who accompanied the main train to Fort Benton. 



Mouse river presents a new river character in the deep and ramified coulees which intersect 

 the valley in every direction, in other respects closely resembling the Shayenne, having a narrow 

 but dense fringe of oak, ash, maple, and other timber, filling the intervale, and extending some 

 way up the intricate coulees ; in some of which are found small streams in sandy beds, and massive 

 sandstone rocks. Many of them reach to the edge of ihe Missouri plateau, which is here well 

 defined ; and in the examination for a good passage for the wagon train, secluded spots were found 

 where beetling crag and winding stream, venerable trees and greenest sward, combined in scenes 

 of much picturesque beauty. 



The main route strikes Mouse river at its most southerly bend, about one hundred and twenty- 

 five miles from Lake Jessie, from which point the river turns abruptly northward towards its 

 confluence with the Assiniboin. In the same general course of northwest the route runs nearly 

 parallel to the course of Mouse river, heading the coulees for thirty miles, when the river is 

 found coming down from the north, being joined at this turning point by the Riviere des Lacs, 

 which flows southeast from the most northern edge of the great plateau, of which it may be 

 assumed as a boundary. From Dog House hill to the junction of the Riviere des Lacs the 

 coteau decreases in elevation, until blended insensibly with the rolling prairies rising from that 

 river. On the approach to these high prairies from the more open country the swelling outline 

 assumes the appearance of a distant coast, which seems to rise in a direction parallel to the 

 route of the traveller, and suggests the idea of a plateau or bench of table-land beyond ; hence the 

 use of the word &quot; coteau.&quot; But this appearance has proved so frequently deceptive with reference 

 to the extent of tracts exhibiting it, that only a thorough exploration can be relied upon: thus the 

 preliminary sketches in the neighborhood of Fort Union represented this phantom coteau running 

 in whatever direction the line of examination was conducted; so that it will be only when all the 

 detached surveys are combined that the exact extent of these plateaux can be determined. 



The plateau between Missouri and Mouse rivers cannot be called simply a rolling prairie, 

 though in detail resembling the hilly prairies noticed, but in a very exaggerated degree : a general 

 similarity of outlines; the absence of wood and rocks in place; boulders plentiful; ponds and 

 marshes if possible more frequent ; but the elevations so much greater as to be almost considered 

 mountainous, and becoming still more rugged on the approach to Fort Union, where it ends 

 abruptly on the level intervale of the Missouri. It is intersected by numerous water-courses, 

 which run dry in summer, showing the same character of sandy and clayey soil in the bottoms, 

 which is also seen in the rain-worn sections of the most elevated points. The principal of these 

 is the White Earth river, its character being partly indicated by its name, heading in several 

 marshy lakes within the limits of the plateau, and flowing in a winding southerly course to the 

 Missouri about fifty miles east of Fort Union. Vegetation is generally scanty on this plateau ; 

 grass is rank in the bottoms, but mostly thin and inferior for grazing; the prickly pear, the most 

 common kind of cactus, begins to appear; and the wild turnip is found in comparative abundance, 

 being the only useful production, and probably the only vegetable food of the wandering Indians, 

 by whom it is regularly gathered. 



North of the plateau an admirable reconnaissance by Mr. Lander develops a low, marshy 



