INTRODUCTION. Xxi 
Columbia, to the Pacific; by the Missouri or Mississippi to the Gulf of 
Mexico; by the St. Lawrence to the Atlantic, and also by the Elk or 
Mackenzie River, whose upper streams approach the north branches of 
the Saskatchewan to the Arctic Sea. The fourth great river which 
takes its rise from the same quarter of the Rocky Mountain range is 
the one just mentioned,—the Mackenzie, which is the third of the 
North American rivers in respect of size, being inferior only to the 
Missouri and St. Lawrence. The two principal arms of the Mackenzie 
are the Elk and Peace rivers. One of the main streams of the former, 
the Red Deer River, issues from the vicinity of the northern sources of 
the Columbia and Saskatchewan, whilst other feeders interlock with 
the head waters of the Beaver, Missinippi, or Churchill river. Having 
passed through the Athapescow Lake, the Elk River is joined by the 
Peace River, which, originating somewhat further north in the moun- 
tains within three hundred yards of the source of the Tacootchtessé or 
Frazer’s River, affords a canoe route to all parts of New Caledonia. 
It is a singular fact, that the Peace River actually rises on the west 
side of the Rocky Mountain ridge, and is a large stream navigable for 
boats at the place where it makes its way through a narrow gorge 
bounded. by lofty mountains, which are covered with eternal snows. 
Nearer the source of the river, and between it and the Tacootchtessé, 
the mountains are less lofty and more distant, and the country has 
there much of the character of elevated table-land. After its union 
with the Peace River the Elk River assumes the name of Slave River, 
which, on passing through Great Slave Lake, becomes the Mackenzie. 
At a considerable distance below the last-mentioned lake, and where 
the Mackenzie makes its first near approach to the Rocky Mountains, 
it is joined by a large stream, which rising a little to the northward of 
the Peace River, flows along the eastern base of the mountains. It 
obtained the name of the River of the Mountains from Sir Alexander 
Mackenzie; but its magnitude has since gained it the appellation of 
the South branch of the Mackenzie from the traders. The Mackenzie 
receives several other large streams on its way to the sea, and among 
others Great Bear Lake River, whose head-waters rise on the banks of 
