NATURAL AREAS AND REGIONS 



145. 



ber to May, there is no month in 

 which temperatures below zero are not 

 recorded. The minimum recorded 

 is —80°, and temperatures from —40° 

 to —60° are frequent. For the month 

 of January, the mean for a typical 

 northerly interior station is about —30°. 

 For the same station the mean for July 

 would be about 65°. 



C. Biota. Practically the whole re- 

 gion is in virgin condition. About the 

 small settlements and the few larger 

 towns, the timber has been cut, but in 

 comparison with the whole, these areas 

 are infinitesimal. The game and es- 

 pecially the fur-bearing animals, as 

 beaver and marten, have been much re- 

 duced in some parts, but is not seriously 

 threatened while federal regulations 

 are enforced. 



Vegetation: Along all watercourses 

 in the interior, there is practically con- 

 tinuous forest consisting of a very small 

 number of species of trees, none of which 

 grow to large size. The principal conifer 

 is the white spruce {Picea canadensis) 

 which is generally distributed, some- 

 times in pure stands, but frequently 

 associated with deciduous trees which 

 nearly or quite equal the conifers in 

 numbers. The black spruce {Picea 

 mariana) is abundant, but confined 

 mainly to swampy ground. These are 

 the only conifers in the entire region, 

 except the larch {Larix) which has been 

 recorded at a few stations. The balsam 

 poplar {Populus balsamifera) and the 

 aspen {Populus iremuloides) are the 

 common deciduous trees, but the paper 

 birch (Betula papyrifera) is numerous. 

 Alders and willows also are abundant. 

 This forest usually extends only a short 

 distance away from the water courses 

 and the small divides are but sparsely 

 timbered and especially to the north- 

 ward the timber is restricted to a thin 

 line of trees on the actual banks of the 

 rivers. In the mountains, timber as- 

 cends to 1500 ft. or more in central 

 Alaska and gradually drops down as it 

 goes northward until finally it dwindles 

 to its limit at practical sea-level. The 

 areas above timber have Alpine floras 



including plants not found in the low- 

 lands and these areas gradually merge 

 with the Arctic tundra. 



Animals: Large mammals include the 

 moose, caribou, white mountain sheep, 

 grizzly bear, black bear, lynx, gray wolf, 

 red fox, marten, mink, weasel, wolverine. 

 Small mammals are mostly Palaearctic 

 types, as voles {Microius, Euoloniys, 

 Synaptomys), lemmings {Lemmus) and 

 ground squirrels {Citellus). The num- 

 ber of species is small, but individuals 

 are often excessively abundant. The 

 birds, likewise, are largelj^ of genera and 

 frequently of species which have a 

 transcontinental range from Labrador to 

 Alaska. They include as breeders the 

 common ducks, geese and shorebirds 

 which pass through the United States 

 as migrants. Northern forms of the 

 ruffed grouse and the Canada grouse 

 are generally distributed and smaller 

 birds include Canada jay, three-toed 

 woodpecker, pine siskin, slate-colored 

 junco, fox sparrow, hermit thrush, and 

 robin. The fauna is almost entirely 

 distinct from that of the coast region 

 although in one place (Cook Inlet), the 

 interior fauna extends to the coast. 



D. Travel conditions. The interior is 

 accessible by regular rail and steamship 

 transportation from three principal 

 points. From Skagway, there is rail 

 connection with navigable waters of the 

 upper Yukon in Canadian territory 

 whence the whole Yukon system can be 

 traversed. From Cordova, by rail, and 

 from Valdez, by government trail, the 

 Copper River valley is reached. From 

 Seward on the Kenai Peninsula there is 

 rail connection with Fairbanks and the 

 Tanana Valley. 



Flat-bottomed river steamers ply on 

 the Yukon and at least to certain points 

 on its larger tributaries. Canoe travel 

 is largely practiced, and for downstream 

 work, rafts and roughly made wooden 

 boats are successful. There are some 

 trails, but no roads, and overland travel 

 in summer is done with horses or on foot 

 with Indian packers who are available 

 in some places. Winter travel is by 

 dog sled and, aside from other considera- 



