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NATURALIST'S GUIDE TO THE AMERICAS 



southern tributaries is very rough and 

 rocky, though fairly well wooded, and is 

 traversed in various directions by 

 ranges of low mountains. 



G. Region north of Great Bear Lake. 

 North of Great Bear Lake lies an area 

 of considerable size bounded on the 

 west by the Mackenzie, on the east by 

 the lower Coppermine and Coronation 

 Gulf, and on the north by the Arctic 

 Ocean, into which flow most of its 

 rivers. Its southern portion is sparsely 

 wooded; its barren northern part re- 

 ceives narrow tongues of forest along 

 the northward flowing rivers. Its fauna 

 and flora, therefore, are those of the 

 northern stunted forest and the Barren 

 Grounds, about equally divided. Its 

 surface is mainly rolling with some 

 ranges of low hills, and many lakes. 

 Its climate is essentially Arctic. 



H. The Liard River Valley. TheLiard 

 River has its sources west of the Rocky 

 Mountains, one of its branches rising 

 within 150 mi. of the Pacific. 



In its upper portion the Liard bears a 

 strong superficial resemblance to the 

 upper Peace, being formed by large 

 north and south trending branches which 

 unite west of the mountains and, like 

 the Peace, cut eastward through the 

 main range of the Rocky Mountains. 

 Fort Nelson River, entering the Liard 

 from the south, is its principal branch 

 east of the mountains. It rises near 

 the headwaters of Pine River (north), 

 and pursues a very tortuous northerly 

 course to the Liard. Below the junction 

 the Liard flows northerly and then 

 northeasterly, still being bordered on 

 the western side by spurs of the Rocky 

 Mountain range. The country east of 

 the lower Liard is mainly low and 

 swampy in character. The valley of 

 the lower Liard is heavily wooded, the 

 largest tree being the balsam poplar 

 (Populus balsamifera), which here attains 

 perfection of habit, and from which the 

 river is said to take its name. The 

 other forest trees also are those common 

 to the whole region. 



The upper reaches of the Liard are 

 most readily reached from the Pacific 



side, by ascending the Stikine, and 

 crossing the low height of land. 



The climate of the Liard River Valley, 

 like that of the Peace, varies widely in 

 the different sections. The upper part 

 of the river, lying west of the main 

 divide, enjoys a climate much tempered 

 by the warm Pacific winds. The upper 

 Nelson River also, the principal tribu- 

 tary of the Liard east of the mountains, 

 lies far to the southward and sufficiently 

 near the Pacific to come within its 

 modifying influence. Unfortunately no 

 exact data regarding the temperature 

 of the upper Liard or the Nelson are at 

 hand; hence the conditions there can not 

 be compared directly with those on its 

 lower course. The average temperature 

 conditions on the lower Liard may be 

 fairly represented by those taken at 

 Fort Simpson in 1900. The warm west- 

 erly winds which reach the valley of the 

 Liard extend their influence as far as 

 its mouth and have been known to cause 

 a pronounced thaw there even in Janu- 

 ary, the coldest month. This modifying 

 influence is apparent in the character 

 and progress of vegetation, the migra- 

 tion of birds, and in other phenomena. 

 It is especially manifest, however, in 

 its relation to the breaking up of the 

 river and the attendant effect on the 

 conditions along the banks. Further- 

 more, the disruption of the Liard ice 

 starts that in the Mackenzie also, which 

 thus opens considerably earlier than 

 would be the case were it not affected 

 by its warmer tributary. This, of 

 course, has its natural effect in accelerat- 

 ing the progress of vegetation on the 

 banks of the Mackenzie below the Liard. 



At Fort Liard, the river freezes up 

 between the last of October and the 

 middle of November and usually opens 

 about the first of May. 



/. Northeastern British Columbia and 

 Yukon. Reference has already been 

 made to the fact that both Peace and 

 Liard rivers rise west of the main ranges 

 of the Rocky Mountains which farther 

 south form a strict watershed, but which 

 are here traversed by these great 

 streams. There results a large area in 



