2 BULLETIN 418, U. S. DEPARTMENT OP AGEICULTUEE. 



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 yeUow 

 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 cormnercial yellow-pine forests, and probably 

 as large a proportion of the merchantable timber. Western yeUow 

 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 yeUow- 

 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 yeUow pine. The yeUow 

 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 

 Cahfornia 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 VaUey. 

 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 fine," 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 yeUow 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. 



