The Douglas fir (figs. 2, 3, 4, and 5) is the best known and the most
important timber tree of western North America. It is found from
British Columbia southward to northern Mexico. The finest forests occur
in Oregon and Washington at low elevations. The Douglas fir is common in
the park up to 3,500 feet, sometimes in nearly pure stands, but more
often mixed with other species. It grows in all situations. In the
higher mountains it prefers warm southern exposures and is seldom found
on wind-swept ridges. It seeds annually, but most profusely at intervals
three or four years apart. The red squirrels gather and store large
quantities of the cones in order to provide a supply of the seeds for
their winter rations. The growth of the young tree is very rapid. As the
tree becomes older the rate of growth varies with the situation and the
character of the soil so that the size does not closely determine the
age of the tree.
[Illustration: FIG. 2.--Douglas fir (_Pseudotsuga taxifolia_).]
The Douglas fir is a long-lived tree, and specimens are occasionally
found 250 to 270 feet high and over 8 feet in diameter and between 400
and 500 years in age. It reaches its greatest height and most perfect
proportions in mature even-age stands growing on fairly moist
well-drained bench lands. Under these conditions it is a very tall and
beautiful tree. The trunk is straight, round, and free from branches for
two-thirds of its height and tapers gently to the crown. The dark-brown
deep-furrowed bark is 5 to 10 inches thick at the base of the tree.
The Douglas fir ranks first among the trees of the Pacific slope in
importance for the production of lumber. It is often sold under the name
of Oregon pine. Lumber dealers class the coarse-grained reddish wood
produced by the young growth in open forests as "red fir." The older
growth produced when the forest is more dense is a finer grained and
more valuable wood, sold under the name of "yellow fir."
[Illustration: FIG. 3.--Douglas fir (_Pseudotsuga taxifolia_).]
The Douglas fir is used for nearly all purposes where durability,
strength, and hardness are desirable. It is made into dimension timbers,
lumber, flooring, and is particularly adapted for masts and spars. The
lumber is shipped by rail to the Middle Western States. The foreign
cargo shipments are made to all parts of the world. The greatest amount
goes to Australia, the west and east coasts of South America, China, the
United Kingdom, and Europe, Japan, and the South Sea Islands. Coastwise
shipments are made to California, Alaska, and Panama. Large quantities
of the seed of this tree are sent to Europe, where the Douglas fir is
grown for timber and for ornament.