10 BULLETIN 50, IT. S. DEPARTMENT OF AGRICULTURE. 
soil, but there are many gravel beds that have only a thin covering 
of fertile soil. Much of the soil, particularly of the benches and 
low hills, is composed largely of material deposited by the melting 
of the ice sheet that formerly covered the land. 
Drainage is an important and widespread need in Alaskan agri- 
culture, not merely in the southeastern section where the rainfall 
is so abundant, but in the interior where the precipitation is so light 
that irrigation is thought by some to be a possible essential. 
Wherever the soil is at all peaty, from the accumulation of partly 
decayed vegetable matter, drainage will greatly improve the con- 
dition. Shallow lakes and partially dried lake beds abound, and 
the draining of these will make available for tillage much good 
land and will be otherwise beneficial. It is noticed that wherever 
the tundra moss is disturbed in such a way that drainage has re- 
sulted incidentally, as has been done at St. Michael in connection 
with building operations, grasses come in and make a luxuriant 
growth. 
Notwithstanding the need of drainage, even in the interior, as 
has been stated, some of the settlers are of the opinion that irriga- 
tion will be necessary in certain localities, and a few have installed 
irrigation systems. It is not probable, however, that irrigation will 
be a general or pressing need. The ground is usually frozen to a 
great depth during the long and severe winters and, of course, thaws 
quite slowly after the frost line has fallen a foot or so. So long 
as there is frost in the ground drainage will be retarded, and as the 
frost slowly melts it will supply moisture by capillarity to the surface 
soil. The shortness of the growing season and the tendency of 
vegetation to rapid growth and early maturity under the influence 
of the almost continuous sunlight will lessen the need of irrigation. 
POSSIBLE AGRICULTURAL AREAS. 
So far as topography, soil, and climate determine the matter, 
Alaska has probably 100,000 square miles of area on which there 
are possibilities for farming and grazing. The larger portion of 
the farming land is in the interior, in the Yukon drainage. Not- 
withstanding the mildness of the climate and the accessibility of 
the south coast, the precipitous topography to the water's edge makes 
tillable land very limited, particularly in the southeastern section, 
where the excessive precipitation and much cloudy weather are also 
agricultural handicaps. Of tillable land contiguous to the south 
coast from southeastern to southwestern Alaska, probably not more 
than 1,000 square miles are available. In the Copper Kiver drain- 
age, 100 miles back from the coast, there are possibly 2,000 square 
