2 BULLETIN 1200, U. S. DEPARTMENT OF AGRICULTURE. 
ests and the methods by which new stands may be obtained is the } . 
purpose of this publication. | 
Douglas fir is so intimately related to other species in establish- 
ment and growth that it is necessary in a discussion of this kind 
to consider its chief associates, such as western red cedar (Thuja | 
plicata Don.), western hemlock (Ysuga heterophylla (Raf.) Sarg.). |‘ 
ig. 1.—Regional distribution of Douglas fir in Oregon and Washington. | 
noble fir (Abées nobilis Lindl.), silver fir (Abzes amabilis Forb.), | 
and others.® | 
DISTRIBUTION OF DOUGLAS FIR. 
The local distribution of Douglas fir in Oregon and Washingtor 
is definitely related with the climatic conditions prevailing in the — 
3 For methods of study used in this investigation,. see Appendix A. 
