240 FERNOW 



trees of the North Atlantic region, also occur here. The 

 gray pine and the balsam fir of the Atlantic region are 

 replaced by allied forms of the same genera. The larch 

 alone, of the denizens of the extreme northern forest of 

 the Atlantic coast, finds no congener here in the northern 



/ O 



Pacific forest." 



These determinations of species we may accept for the 

 spruce, birch, poplar and aspen of the interior forest flora 

 of Alaska, but the occurrence of pine and fir seems very 

 doubtful, although Pin us contort a approaches the boun- 

 dary from the British possessions, and Abies lasiocarpa 

 was found at the top of White Pass and may be found at 

 timber-line elsewhere in the interior. 



From the accounts of all explorers, it appears that the 

 interior is in general an open plateau, hill, and mountain 

 country, mostly moss-covered and devoid of trees ; but with 

 scattered more or less open groves on the lower hill slopes 

 and ridges, and in some of the valleys (White River 

 basin 1 ), the trees usually crowding together more densely 

 along the banks of rivers and lakes and covering with 

 dense thickets the many islands in the rivers. In some 

 localities the heads of all the streams are surrounded by 

 timber; Lieut. Henry T. Allen reports that his camp on 

 the Tozikakat River * " was in a grove of larger timber 

 than any seen since leaving the Yukon; one tree was 

 nearly two feet in diameter"; and at another place he 

 mentions the use of a spruce for a bridge over a river forty 

 feet in width. 



While the trees are mostly short, poorly developed, 

 dwarfed, and standing in open positions, in consequence 

 of which the timber is knotty and checked by frost, these 

 groves occasionally assume a real forest character and 

 contain trees developed to good size. Local conditions 

 of soil, and of shelter from the winds, seem to be largely 



1 Allen: Reconnaissance in Alaska, 1887. 



