NATURAL AREAS AND REGIONS 



121 



caribou along the entire coast of north- 

 ern Alaska and Yukon, and great reduc- 

 tion in their numbers east to the region 

 of the Coppermine. During the same 

 period the musk-ox has been extirpated 

 from most of its former range from Coro- 

 nation Gulf westward. 



III. NATURAL DRAINAGE AREAS AND 

 PHYSIOGRAPHIC REGIONS 



1. The Mackenzie and Upper Yukon 

 Basins 



In any description of northern North 

 America from the standpoint of the 

 traveler one must be guided in his 

 method of treatment by its waterways, 

 which now, and which probably will for 

 many years to come, afford almost the 

 only means available for visiting its most 

 interesting sections. Thus considered, 

 the valley of the Mackenzie is by far 

 the largest and most important of the 

 natural divisions. Broadened to in- 

 clude certain areas not actually drained 

 by this great river system, but which can 

 most readily be reached by its help, it 

 comprises a vast region in the northern 

 part of Canada, with an area of nearly 

 700,000 sq. mi., bounded roughly as 

 follows: On the north by the Arctic 

 Ocean; on the east by the valleys of the 

 Great Fish, Thelon, Telzoa, and 

 Churchill rivers; on the south by the 

 Churchill and Saskatchewan valleys; 

 and on the west by the main range of 

 the Rocky Mountains. 



For convenience of reference the 

 Mackenzie basin may be divided into 

 several areas: The Athabaska Valley; 

 the basin of Athabaska Lake; the Peace 

 River Valley, including the Slave; the 

 basin of Great Slave Lake; the Macken- 

 zie Valley proper; the basin of Great 

 Bear Lake; the region to the north of 

 that body of water, and drained *by the 

 Anderson and smaller rivers which enter 

 the Arctic Ocean, and the Liard River 

 Valley. The areas will be considered in 

 the order given. These accounts will 

 be followed by a description of north- 

 eastern British Columbia and Yukon, 

 comprising the drainage areas of the 



Upper Liard and Yukon rivers, and of 

 the Stikine and other rivers which reach 

 the Pacific in middle British Columbia. 



A. The Athabaska Valley. The Atha- 

 baska River rises in the Rocky Moun- 

 tains near Mount Brown, at an altitude 

 of about 5700 ft., and pursues a north- 

 easterly and northerly course for nearly 

 600 mi. to Athabaska Lake, falling in this 

 distance some 5000 ft., and being in- 

 terrupted by several series of rapids. 

 In the first 300 mi. of its course it falls 

 about 4000 ft., and receives in succession 

 Baptiste River from the west, the Mc- 

 Leod and Pembina from the south, and 

 the Lesser Slave from the west. Below 

 its confluence with the last-named stream 

 the Athabaska turns southeastward for 

 some 50 mi. and then resumes its north- 

 erly course. In the course of the next 150 

 mi. it receives in succession La Biche 

 River, Quito or Calling River; Big 

 Mouth Brook; Pelican River; and House 

 River. Just below the mouth of the last 

 river the Athabaska strikes a range of 

 low hills, and in forcing a passage 

 through them is deflected eastward, and 

 for a distance of about 75 mi. contains 

 many rapids, falling in this distance 

 some 400 ft. At the lower end of this 

 stretch it receives the waters of Clear- 

 water River, its principal tributary below 

 Lesser Slave River. The Clearwater 

 rises on the height of land between 

 the Churchill and the Athabaska, and 

 30 or 40 mi. above its mouth it is joined 

 by the Pembina, a stream of about equal 

 volume. 



The country drained by the Athabaska 

 is mainly a rolling plain, and with the 

 exception of a few areas of semiprairie 

 land is well wooded with a forest com- 

 posed mainly of spruce, fir, pine, tama- 

 rack, poplar, birch, and willow. A large 

 part of its surface is occupied by mossy 

 swamps, called muskegs, and hundreds 

 of lakes, of which Lesser Slave, 70 mi. 

 in length is by far the largest, occupy its 

 shallow valleys. 



The country lying between the Atha- 

 baska and Peace rivers, and drained in 

 part by the latter stream, may be best 

 characterized by quoting in part the 



