BULLETIN 418, U. S. DEPAETMENT OF AGEICULTURE. 



DESCRIPTION. 



Western yellow pine is a large, well-formed timber tree.^ In old 

 trees the bole is usually straight and fidl-formed. It is well cleared 

 of dead branches, but usually clothed with live branches for from 

 one-half to two-thirds its height. The maximum diameter is 8 feet 

 and the maximum height 220 feet.^ The largest tree measured in 

 the course of a volume study of over 2,500 feUed trees in various 

 parts of Oregon was a little over 6 feet in diameter at breastheight 

 and the tallest was 177 feet high. The usual size at maturity is about 

 3 J feet in diameter and 110 feet in height. Table 2 gives the prevailmg 

 height of yellow-pine trees of various diameters in two regions of the 

 State, one near Lookingglass Creek, Union County, growing excep- 

 tionally tall, fine timber, and the other near the edge of the desert at 

 Bend, Crook County, where the timber is short. Most of the yeUow- 

 pine timber of the State would fall between these two extremes. 



Table 2.— Average total height of several hundred trees of various diameters on two sites, 

 one exceptionally good for tree growth and the other poor.^ 



Diameter at 

 breastheight. 



Total height. 



Diameter at 

 breastheight. 



Total height. 



Diameter at 

 breastheight. 



Total height. 



Look- 

 ing- 

 glass 

 Creek. 

 Union 

 County. 



Near 



Bend, 



Crook 



County. 



Look- 

 ing- 

 glass 

 Creek, 

 Union 

 County. 



Near 



Bend, 



Crook 



County. 



Look- 

 ing- 

 glass 

 Creek, 

 Union 

 County. 



Near 



Bend, 



Crook 



County. 



Inches. 



12 

 14 

 16 

 18 

 20 



Feet. 



71 



82 



91 



100 



108 



Feet. 



""ih" 

 57 

 65 

 72 



Inches. 



22 

 24 

 26 

 28 

 30 



Feet. 

 115 

 121 

 127 

 131 

 135 



Feet. 

 78 

 84 

 88 

 92 

 96 



Inches. 



32 

 34 

 36 

 38 

 40 



Feet. 

 138 

 142 

 146 

 149 

 152 



Feet. 

 98 

 101 

 102 

 103 

 104 



1 In the Appendix are two volume tables which show the average contents in board feet of trees of various 

 diameters and heights for two regions in Oregon. The average tree over 16 inches in diameter in the virgin 

 stand contains about 1,000 board feet, and the average log about 250 feet. Trees with a volume of over 

 5,000 feet are very rare. 



The bark of the trimk in yomig trees is dark gray-brown, roughly 

 fmTOWed, and from 1 to 3 inches thick; in old trees it is tan colored 

 (or "yellow"), is broken with rather large, irregular plates, and is 

 commonly about 1 inch in thickness, and on very old trees even 

 thmner. The crown is at first bluntly conical, but, as the tree 

 matures, it becomes more and more roundheaded and bushy; on 

 old trees it is quite fiat-topped, and the upper branches are heavy and 

 gnarled. The root system of mature trees consists of extensive, deep 

 branching laterals which give the tree firm support. The foliage is 

 not extremely heavy, so that the shade cast by yellow pines is not 



1 The forest characteristics of this tree vary decidedly in different parts of its wide range. The yellow- 

 pinestands of the Black Hills are quite unlike those of the mesas of the Southwest, which are in turn unlike 

 those of the eastern Oregon plateau or of the Sierra Mountains of California. 



2 Measured by John Muir in the Sierra Mountains of California. 



