WESTERN YELLOW PINE IN OREGON. 29 
immeasurable factors — lessened number of trees per acre after cut- 
ting, occasional loss of some trees on account of accidents, increased 
growth after cutting due to more growing space — point to the con- 
clusion that central and eastern Oregon yellow-pine timberland can 
be counted upon to yield annually for an indefinite time from 75 
board feet per acre on poor sites to 175 board feet on good sites. 
This is not large when compared with the 800 or 1,000 board feet per 
acre per year yields of the best Douglas-fir forests west of the Cas- 
cades; but the climate in the yellow-pine belt is such that the pro- 
ductivity of the forest soil is inevitably not large. 
CHARACTERISTICS OF THE WOOD. 
Botanically western yellow pine belongs to the subfamily of the 
hard or " yellow" pines rather than to that of the soft or " white " 
pines. In characteristics the wood is midway between the two. It 
is described as follows: 1 
Rather light, not strong, grain fine, even, often twisted; annual rings variable in 
width, summerwood broad or narrow, resinous; resin passages medium and rather 
numerous; medullary rays not numerous, prominent; color very light yellow to red- 
dish, thick sapwood almost white; not durable in untreated condition, but readily 
receives treatment. 
The smaller trees, i. e., the so-called "bull pines," and the centers 
of the larger trees have a coarse-grained wood, in which the annual 
rings are prominent and the summerwood rather hard, resembling 
that of some of the southern yellow pines. The outside of the larger 
trees, particularly of the slower-growing ones, is soft, uniform- 
textured, and resembles strongly the wood of the eastern white pine, 
western white pine (Idaho white pine), and sugar pine. The wood 
from the outside of the lower logs of old trees is apt to be fairly clear 
of knots, the worst defect in this lumber; but that from the upper 
part of the tree and from young trees is almost always knotty, even 
though the outside of the log may appear fairly smooth. Much of 
the yellow-pine timber cut in Oregon is so soft and white that it is 
shipped east and used with satisfaction for purposes for which real 
white pines and sugar pine have been used previously. The char- 
acter of the wood varies with the situation, a fact well known to 
lumbermen, who find that the timber in certain localities produces 
a larger percentage of the high-grade soft "shop" lumber than that 
in other localities where it is similar in exterior appearance. 
The following statistics summarize the characteristics of the wood. 2 
Average weight of oven-dry wood, 26.5 pounds per cubic foot. (Sargent.) (Excep- 
tionally soft, light specimens from central Oregon weighed, air dry, 22 pounds per 
cubic foot.) 
1 Forest Service Bulletin 99, "Uses of Commercial Woods of the United States; II, Pines." 
2 For further description of the wood, see Forest Service Bulletin 101, "Western Yellow Pine in Ari- 
zona and New Mexico," by T. S. Woolsey, p. 33. 
