ALASKA. 39 
On the relief model the submarine platform is strikingly shown. 
This attains a width of about 25 miles on the south coast and occupies 
a large portion of Bering Sea, extending 450 miles off the mouth of 
the Kuskokwim. Unalaska, a town of the Aleutian Islands, is situated 
nearly on the line where the surface of the submarine platform falls off 
abruptly to the depths of the Pacific. 
CLIMATE, VEGETATION, AND RESOURCES. 
Very erroneous impressions have prevailed about the climate of 
Alaska. The area is so large that a great variety of climate is to be 
found in its different portions. The climate of the southeast coast 
resembles that of the northwest coast of the United States, but farther 
north and west the winters become longer and colder, and Arctic 
conditions prevail in the interior. The summers, even to the Arctic 
Circle, are hot and the length of the day furnishes abundant oppor- 
tunity for the growth of vegetation. 
Among the mountains of the Pacific system climatic conditions have 
produced many glaciers, making this portion of Alaska one of the 
finest fields in the world for the study of glacial phenomena. The 
varied climatic conditions which have covered the highest peaks 
with eternal snow and glaciers have clothed the lower ranges and 
foothills with moss, all the coastal regions west of Kodiak and north- 
ward to the Arctic Ocean with the greenish-brown vegetation of the 
tundra, and the river valleys from the Kowak (or Kobuk) southward 
with an increasing growth of timber. The distribution of vegetation 
is instructively shown on the relief model. 
The resources of the country have more than proved the wisdom of 
its purchase. At first furs, fish, and timber were supposed to be the 
only valuable products, but gold, copper, silver, tin, and coal are now 
produced. The search for these metals and their exploitation has 
resulted in an increase of the white population from 430 in 1880 to 
over 30,000 in the decade 1890-1900, and has led to the rapid explora- 
tion of the mineral resources and active participation by the Geological 
Survey in the development of the country. 
OPERATIONS OF THE ALASKAN DIVISION. 
The preceding brief sketch is intended to show in a general way 
the objects of the work which the United States Geological Survey is 
doing in Alaska and the conditions under which the work must be 
done, and it will serve as a basis for the following account of the 
results accomplished by the organization. 
In 1898 plans were made to survey as much as possible of the por- 
tion of Alaska that lies south of the Yukon River. A combined force 
of geologists and topographers was sent to the field in the early 
spring, and transportation to Alaska was furnished by the Navy 
