EXTRACTS FROM TINKHAM S REPORT. 87 



cost. The great valley of Milk river affords remarkable facilities for construction, as regards 

 grading and the immediate use of the rail. Vicinity to the Missouri aids transportation of tim 

 ber from the mountains by rafting. 



An embankment road-bed must be resorted to in the valley of Milk river, to guard against rise 

 of water upon the bottom land over which the line will pass. 



2. Extracts from Mr. Tinkkam s report. From the Mississippi a vast prairie stretches westward 

 to the base of the Rocky mountains, 1,136 miles; and a breadth of 402 miles of wooded and 

 mountain country lies between the prairies and the great Columbia river plains. These prai 

 ries reach down to the bottom lands of the Columbia, whose valley, including that of its tributary, 

 the Cowlitz, is traced to the shores of Puget sound a third portion of 507 miles. These 

 are the measured distances of the railway route hereafter defined, and are changed by adopting 

 for portions of the line other practicable or probably practicable routes. 



From the Mississippi to the bottom levels of the Missouri are certain prominent and unusual 

 features, the knowledge of which is of great service in directing the location of the line of rail 

 way, the easiest and cheapest line between the headwaters of the Mississippi and the great 

 northern bend which the Missouri makes near the mouth of the Yellowstone. It may nevertheless 

 be observed, with reference to the region lying between the Mississippi and Missouri, that so far 

 destitute is it of serious obstacles, that the great selection of a railway route uniting the two rivers 

 may be determined by the commercial relation rather than by the physical features of the coun 

 try traversed. 



The section of Minnesota east of the Mississippi, passed over by the exploration, presents few 

 difficulties to the building of a railroad. Obstructed by no mountain ranges, and diversified by 

 lightly-wooded lands, the fertile belt of prairie bordering on the river affords a good location. 

 Farther interior, on the east, and to the north and northwest, are the wooded and lumber sec 

 tions. 



Bordering on the Missouri, and running parallel with it, is the Plateau du Coteau du Missouri 

 a high rolling plateau, having an average breadth of some 60 to 80 miles, rising from 400 to 

 800 feet above the bed of the river. This plateau, remarkable for its uniformity and extent 

 from below the latitude 44, stretches north and west into the British possessions, and probably 

 here retains its characteristic features as the dividing ridge between the waters of the Sascat- 

 chawan and the Missouri, until absorbed in the bolder elevations of the eastern slope of the 

 Rocky mountains. 



The passage of the plateau by a railway will by no means be impracticable with a careful 

 selection of route ; but it can rarely be done without a loss of grade greater than 400 feet. 



East of the plateau and parallel with it, at distances of from 20 to 50 miles from its eastern 

 edge, flows Riviere a Jacques, or James river, finding its source near the headwaters of the 

 Shayenne, and having with that river, for some 100 miles, nearly the same general southeasterly 

 course. 



The general surface of the high plains through which these two streams find their descent the 

 one to the Red river of the North, the other to discharge its waters into the Missouri is here 

 400 to 600 feet lower than the plateau. Of this summit-ground, distributing and dividing the 

 waters to their northern or southern slopes, the extensive flat or prairie through which flows the 

 Bois des Sioux river is the eastern limit. The connexion between this prairie and the Mississippi 

 is along the sources of the tributaries to the Minnesota river. Crossing these streams in their 

 infancy, and before the crossing of the several valleys, is objectionable. 



Carrying the line northwardly to the great bend of the Missouri, we avoid a difficult and ob 

 jectionable river-crossing, and, what is of more importance, head what is represented as the 

 extensive, broken, and tumultuous region of country south and west of the Missouri and ex 

 tending to the Platte, and known as the Black Hills. 



The railroad route from St. Paul keeps up the left bank of the Mississippi, crosses at Little 



