2 BULLETIN 418, U. S. DEPABTMENT OF AGBICULTUEE. 
400,000,000,000 feet of this pine, more than there is of any other 
single species except Douglas fir. The annual cut is less than 0.004 
of the stand. 
Western yellow pine occurs naturally from southern British 
Columbia to Lower California and northern Mexico, and from the 
Pacific coast nearly as far east as to the one-hundredth meridian. 
It is found in the forests of every State west of the Great Plains, and 
in more than half of them it is the most important and valuable 
forest tree. In Arizona and New Mexico there is a western yellow 
pine forest which is said to be the largest continuous body of timber 
in the country. 
DISTRIBUTION AND ABUNDANCE IN OREGON. 
Of the 12 States in which western yellow pine occurs, California 
has the largest area of forests composed chiefly of this species, and 
Oregon comes second. Together these two States contain nearly 50 
per cent of the area of commercial yellow-pine forests, and probably 
as large a proportion of the merchantable timber. Western yellow 
pine occurs on about 14,000,000 acres in Oregon, practically a quarter 
of the State and half of its timbered land. Of this area about 
10,000,000 acres may be classed as commercial forest, the estimated 
stand amounting to 70,000,000,000 feet, or an average of 7,000 feet 
per acre, inter-forest waste areas included. Although the yellow- 
pine forests cover a larger proportion of the State than do the Douglas- 
fir forests, the fir stands are so much denser that the estimates show 
four times as much Douglas fir as they do yellow pine. The yellow 
pine amounts to from 15 to 20 per cent of all the commercial timber. 
The distribution of yellow pine in Oregon is shown in Plate I. 
The areas of commercial forest, in which yellow pine forms at least 25 
per cent of the stand and in which the quantity is large enough to be 
logged profitably, are shown in the shaded portions. The botanical 
range is indicated by a dotted fine. The species is found from Bonne- 
ville on the Columbia River eastward to Idaho and southward to 
California through all the timbered portion of the State east of the 
Cascade Mountains. North of the Umpqua River and west of the 
Cascades it occurs only in small stands in the Willamette Valley. 
The altitudes at which it is found range from the lowest zone of 
forest growth on the borders of the sagebrush desert, the ''dry tim- 
ber line," which is at from 2,500 to 3,500 feet in eastern and central 
Oregon, up to 5,000 or 6,000 feet (scattered individual trees even 
going to 8,000 feet) on the slopes of the mountains. At this height 
the humidity is greater and the yellow pine gives way to a forest of 
moisture-demanding species. In the southwestern part of the State 
yellow pine occurs abundantly on the west slopes of the Cascade 
and Siskiyou Mountains, from the valley floors to altitudes of 6,000 
feet, particularly in warm situations. 
