332 Capt. Blakiston’s Explorations in the Rocky Mountains. 
length is 40 geographical, or nearly 47 English miles, extending 
from longitude 114° 84’ to 115° 24’ W. It leaves the Saskatch- 
awan Plains where they have an altitude of about 4000 feet 
above the sea, rises 2000 feet to the watershed of the mountains, 
descends to Flathead River, again to an altitude of 4000, follows 
up this river to its head waters, then crosses a precipitous ndge, 
reaching an altitude of 6000 feet; it then descends the great 
western slope, falling 2000 feet in two miles of horizontal dis- 
tance, after which, by a nearly uniform grade of 100 feet per 
geographical mile, it gains the Tobacco Plains at the point where 
the Wigwam branch enters Kootanie River. 
By reference to section No.-1, it will be seen that there are 
