WESTERN YELLOW PINE 171 



favored situations, it grows rapidly and uniformly and lives 

 to the age of five hundred years. It grows from near sea 

 level to 7000 feet above. It may be found growing on the 

 top of dry ridges, on mountain slopes, on high mesas, 

 in dry valleys, and in canyons. It thrives well in volcanic 

 ashes, as will be seen around the base of Mount Shasta, 

 on the headwaters of McCloud and Klamath rivers, and 

 in the glacial moraines and drifts throughout the great 

 mountain regions ; but insists on a well-drained soil, as it 

 requires little soil moisture, apparently less than any other 

 of our valuable timber Pines. It is very variable in char- 

 acter and size and in quality of product, which is not to be 

 wondered at when the diversities of climate, soil, and ele- 

 vation in which it grows are considered. It is deep-rooted 

 and can withstand the gales that sweep the sides and tops 

 of the ridges and scour the valleys where it grows. 



It is essentially a light-demanding tree. It insists on this 

 during its whole life, but most after the age of fifteen 

 or twenty years. Probably not to exceed fifty trees to the 

 acre could be grown to full maturity. The crowns of mature 

 trees do not frequently touch each other or those of other 

 species. Like most other trees it sends out limbs low down 

 in early life, and if continually in the open these branches 

 persist for the full life of the tree and give it a low crown ; 

 but if grown in a close stand it will throw up a tall, straight, 

 slightly tapering, massive stem, clean of limbs for nearly 

 or quite one half its entire height. Under such conditions 

 it will form an open crown, somewhat columnar, with 

 specialized limbs which turn upward at their extremities. 

 Frequently one or more large limbs may be thrown out, 

 and above that point an open, clean stem is seen for twenty 

 or more feet before other limbs are formed. 



The bark on mature trees may reach a thickness of four 

 inches. It is deeply furrowed and of a cinnamon-brown 

 color. In early life it is so thin that fire works serious 

 havoc, but the mature trees can endure a moderate ground 

 fire and the foliage is so far above that the trees escape 



