GENERAL FEATURES. 621 
are wide enough for the arm to be thrust in ; they form a network over 
large areas. 
The hill prairies are often too dry for cultivation, yet afford good 
pasturage. The soil varies in character with the subjacent rocks, 
on the principle just stated. 
As the rains of this part of Oregon are confined to six months out 
of the twelve—from October to May,—the aspect of the country is 
wholly different at different seasons of the year. In the summer it is 
very seldom that a shower passes over the Willammet plains. The 
lofty summits, St. Helen’s and Mount Hood, are mountain hygrome- 
ters, attesting to the general dryness of the atmosphere; it is very rare 
that a cloud appears in this season about their snowy summits, though 
they are at times partially obscured by a light haze. The conse- 
quence is that nothing grows from June till the rains set in again. 
The whole country is without a green blade of grass, except along the 
edge of some rivulet. The drought is so complete that the dried 
grass remains as good food for the cattle till the change in antumn. 
It gives a dreary appearance to the summer prospect of these prairies, 
but little exceeded when later in the season, they are left black after 
the charring fires. During winter, the fields offer fresh feed, and as 
the weather is mild, with rarely any snow, the herds are kept out 
at pasture through the season, housing being unnecessary. 
It is probable that by discontinuing the burning of these prairies 
the grass would grow more closely, and other species might be made 
to spring up. ‘The fires destroy the annual plants and all the smaller 
kinds of vegetation, excepting species with bulbous roots. A system 
of irrigation would bring under cultivation large districts which are 
now unfit for tillage. Yet there is some difficulty in irrigating the 
upper prairies and hills, as there are no sources of water, excepting 
the streams meandering through wide alluvial plains, and lying twenty 
or twenty-five feet below their banks. 
Vancouver, Cowlitz and Nisqually districts—The prairie land in 
the vicinity of Fort Vancouver, in the Cowlitz valley and about Nis- 
qually, has a general resemblance to that of the Willammet. The 
Vancouver farms, in the hands of the Hudson’s Bay Company, are 
small but productive. In the Cowlitz, the plains lie near the head of 
the river. ‘They cover but a few square miles, and six hundred acres 
were under cultivation in 1841. They are described as clayey, and 
similar to much of the Upper Willammet prairies. The region about 
Nisqually on Puget’s Sound, offers great commercial advantages on 
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