From the Pacific to Hudson's Bay. 313 



ary Line, and extends from the 95th to the 113th meridian; another 

 side follows the eastern slope of the Rocky Mountains from the 

 49th to about the 64th parallel of latitude. The third side, about 

 1,500 miles in length, skirts a remarkable series of lakes, rivalling 

 in size Lakes Erie and Ontario. These great water-filled depres- 

 sions lie in a generally straight north-westerly and south-easterly 

 direction. They embrace Great Slave Lake, Lake Athabaska, Lake 

 Wollaston, Deer Lake, and Lake of the Woods, and they appear 

 to occur geologically, on the separating line, between a broad band 

 of Laurentian or metamorphic rocks and the softer Silurian forma- 

 tions. This great triangular-shaped region is estimated to measure 

 about 300,000,000 acres. Its base, running along the series of 

 lakes mentioned, will probably average less than 1,000 feet above 

 the sea ; and its apex, near where the International Boundary Line 

 enters the Rocky Mountains, will probably be about 4,000 feet 

 above sea level. This region may generally be described as a great 

 plane sloping from its apex in a north-easterly direction down- 

 wards to its base, but the inclination is not uniform and unbroken. 

 Several terraces and well-defined escarpments stretching across the 

 country are met with at intervals. A great proportion of the 

 surface is gently rolling, and hills of no great height occur here 

 and there. The rivers of this division of the country flow for a 

 great part of their course in deeply-eroded channels, frequently of 

 considerable width, and as the superficial formations are for the 

 most part drift or soft rock, the channels which have been fur- 

 rowed out are but little obstructed by falls or steep rapids. They 

 generally present a uniform descent, and the long stretches of some 

 of the rivers, although the current be swift, are capable of being 

 navigated. A wide expanse of the region to the south of the main 

 Saskatchewan is a prairie, without trees or shrubs of any kind ; 

 the treeless prairie passes by easy gradations into copse woodland 

 with prairie intervening. To the north of the Saskatchewan, wood- 

 land appears in various localities. On Peace River there are 

 extensive prairies ; there is also an agreeable mixture of woodland 

 and prairie ; and this character of country appears to prevail for a 

 considerable distance still further north. 



