DOUGLAS FIR (Pseudotsuga taxif olio), an important North American timber tree of the pine family (Pinaceae), called also red fir, yellow fir and Douglas spruce. Botanically it exhibits some of the characteristics of the firs and the hemlock, though it most closely resembles the spruces. It is found from South Da kota to British Columbia and southward to Texas and Mexico, but attains its maximum development in Washington and Oregon where it forms immense forests, furnishing the valuable structural timber known in the lumber trade as yellow fir, Oregon fir or Ore gon pine. In the forests of Washington it commonly reaches a height of 18o ft. or 190 ft. with a trunk diameter of 31 ft. to 6 ft. and sometimes attains a height of 25o ft. and a trunk diameter of 10 ft. or 12 ft. Among North American trees it is exceeded in height and massiveness only by the giant sequoias of California. According to the U.S. Department of Commerce, the lumber cut of Douglas fir in 1936 amounted to 6,3 21,000,000 bd. ft., with a value at the mill exceeding $III ,000.000, in footage more than a fourth of the total lumber cut of the United States during that year. Of this production of Douglas fir lumber the States of Washington and Oregon contributed more than 90%.
The closely related big-cone spruce (P. macrocarpa), a much smaller tree, native to southern California, with large cones some times 3 in. thick and 7 in. long, hanging from the widely spreading branches, is of value chiefly as cover on arid mountain slopes.