FORESTS OF MOUNT RAINIER NATIONAL PARK. 7 



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 ra- 

 tions. The growth of the young tree is very rapid. As the tree be- 

 comes older the rate of growth varies with the situation and the 



FIG. 2. Douglas fir (Pseudotsuga taxifolia). 



character of the soil so that the size does not closely determine the 

 age of the tree. 



The Douglas fir is a long-lived tree, and specimens are occasion- 

 ally found 250 to 270 feet high and over 8 feet in diameter and be- 

 tween 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. 



