AGRICULTURAL DEVELOPMENT IN ALASKA. 7 
great and little-explored region, and it is quite possible that there 
are large tillable areas in its valley. 
Small areas of land for gardens may be found even above the 
Arctic Circle along the Koyukuk, Chandalar, and other Yukon tribu- 
taries that come in from the north. The Kobuk River, which empties 
into Kotzebue Sound above Seward Peninsula and lies wholly above 
the Arctic Circle, is said to offer some farming and gardening 
possibilities. 
CLIMATE OF THE INTERIOR. 
Climatic conditions of the interior are determined by the latitude 
and its relation to the bodies of water and mountain systems al- 
ready mentioned. Much of the area of the interior, particularly 
the Tanana Valley and the upper Yukon Valley in Alaska, lies north 
of latitude 64° N., and extends above the Arctic Circle. Cut off from 
the tempering influence of the warm waters of the Pacific that have 
so much effect at the coast, both with reference to temperature and 
precipitation, the result is light precipitation, short but quite warm 
summers, and long, cold winters. It must be remembered that, while 
the summers are short in number of days, there are 18 to 20 hours of 
sunshine daily during the growing season, and that this, with com- 
paratively high temperature, causes very rapid growth of vegeta- 
tion. The lower Yukon and Kuskokwim region is in a lower lati- 
tude, but this is counteracted by proximity to the cold waters of 
Bering Sea, with no protecting mountain range to arrest the cold 
air currents. 
As a result of the long winters, and, generally speaking, low tem- 
peratures, during which the ground is deeply frozen, and the short 
summers, there is frozen earth even in the summer time within a few 
feet of the surface over much of Alaska. Because of this frost line 
the moisture from the melted snow on the ground and the frost in it 
can not drain away and can escape only by evaporation. This con- 
dition of slow melting and evaporation is emphasized by the vege- 
table growth and particularly the moss, which is a most efficient non- 
conductor of heat as well as an excellent sponge for holding moisture. 
Over much of Alaska during the summer there is, then, a thin 
stratum of saturated earth with its protecting coat of moss or other 
vegetation, forming for the most part a morass impassable for 
wheeled vehicles and almost impassable for horses. Land travel by 
teams is therefore practically out of the question in Alaska during 
the summer, even where the mountains and timber growth do. not 
interfere. But with a coast line of 26,000 miles and 6,000 miles of 
navigable rivers, one of which, the Yukon, bisects the territory with a 
1,500-mile waterway, Alaska is marvelously well supplied with facili- 
