1908.] 



PHYSICAL GEOGRAPHY : 



-MACKENZIE RIVER. 



33 



Continuing northward, the Mackenzie is bordered on the west by a 

 broad expanse of mountain country, mainly unex]:)lored. A few 

 low spurs of the same s}'stem cross the river and appear in the 

 form of isolated peaks or disconnected ranges to the eastward of its 

 valley. The principal western tributaries between latitude OS"^ and 

 65° are the Eed Eock and Gravel rivers. In the same interval the 

 Mackenzie receives several small streams which drain the countr\" 

 east of the river. One of the largest of these is the Blackwater. 

 Blount Clark, which is visible from the river at some distance below 

 the mouth of this stream, has an estimated altitude of 3.500 feet, and 

 is the highest of the mountains east of the ^Mackenzie. The most 

 conspicuous landmark in the immediate valley is Eoche Trempe-reau. 

 a limestone mass which rises abruptly from the water's edge a short 

 distance north of latitude 63°. Bear Eiver. the principal eastern 

 tributary of the Mackenzie, joins it just south of latitude 65°. As 

 the outlet of Great Bear Lake, it is described in its proper place (p. 

 4A:). Below its mouth, on the north side of the Mackenzie, is Bear 

 Eock. 1J:00 feet in height. (See fig. T, p. 105.) This mount is com- 

 posed mainly of Devonian limestone. 



Below here the Mackenzie resumes its general northwesterly course. 

 Wolverene Eock. 100 miles below Bear Eock. is formed, like that 

 eminence, by an uplift of the Devonian limestone, and is about 

 1,000 feet in height. Twenty-five miles below here a rocky ridge 

 crosses the river, forming the Sans Sault Eapicl. The next important 

 feature in the valley of the Mackenzie is the defile called the * Eam- 

 parts.' (See fig. 8. p. 106.) Here the river contracts from a width 

 of 2 miles to about 500 yards, and flows for about T miles between 

 precipitous limestone cliffs, which in places rise to a height of 250 

 feet. 



Below Sans Sault Eapicl the Mackenzie recedes from the motm- 

 tains, and they are not again visible luitil the delta is reached. Hare- 

 skin Eiver enters the ^lackenzic from the east a short distance north 

 of the Eamparts. It drains a large extent of rocky wooded country 

 between Great Bear Lake and the Mackenzie. For a long distance 

 below here the Mackenzie maintains a general northwesterly course. 

 A few fair-sized streams enter it from the east, but from the west 

 it receives no tributaries of importance. In about latitude 67° 10' 

 it turns rather abruptly at right angles, and for about 50 miles 

 follows a course considerably south of west. It is here bordered, 

 especially on the north, by high clay banks, through which several 

 good-sized streams cut their way. The river then turns northward 

 again and maintains a northwesterly direction to the delta. The 

 defile called the ' Xarrows ' or ' Lower Eamparts ' is encountered 

 near 67° 4zO\ and at its lower end Arctic Eed Eiver, from the south, 



44131— No. 27—08 3 



