88 EXTRACTS FROM TINKHAM’S REPORT. 
Falls, continues along the dividing ridge between the Mississippi, Red river, and the Minnesota, 
until entering upon the prairie of the Bois des Sioux, pursues its same general direction through 
this prairie, passes thence on to the summit-grounds between the James and Shayenne rivers, 
and finally, without losing its elevation, enters and passes the great plateau of the Missouri by a 
coulée connecting the two valleys of the Mouse and Missouri rivers, and for a time piercing the 
barrier which separates them. 
Proceeding up the Missouri from the mouth of the Great Muddy river to the entering of Milk 
river, the railroad line for nearly 180 miles follows the favorable valley of this latter stream; 
then, leaving it, passes on to the prairies, and so continues until within a few miles of the 
mo ntain pass, crossing in succession Marias, Teton, and Sun rivers, with the tributaries of 
Dearborn river. 
