- 
and 54° north latitude, rise the four great rivers of the contl- 
328 Capt. Blakiston’s Explorations in the Rocky Mountains. 
The entrance of this pass is in latitude 49° 34’ N., and longi- 
tude 114° 34’ W., being (consequently) forty English miles north 
enormous vertical escarpment, facing the east, of hard red sand- 
ing at least 45° to the 
seen by reference to 
r the purpose of reading the barometer, which shewed an altt- 
tude of 5960 feet. It was just five hours since leaving our pre- 
vious night’s camp, at an altitude of 4100 feet. 
This is no place for a dissertation on the physical geography 
of North America, but I may simply state, that in that portion 
of the Rocky Mountains, comprised between the parallels of 49 
nent, namely, the Mackenzie, running north to the Arctic 
Ocean, the Saskatchawan east to Hudson’s Bay, the Columbia 
west to the Pacific, and the Missouri south to the Gulf of Mex- 
‘ ico; thus we may say, that in a certain sense that portion of the 
point of North America, an 
