the virgin ponderosa pine sawlog 

 types (5%, 20, 20A, 20B, 20& 27) 

 where cutting coupled with insect 

 epidemics and fire have reduced the 

 stands from an estimated original 

 area of 12.0 million acres to 9.2 

 million acres. 



By far the most important type 

 of this group is pure ponderosa 

 pine (20%) covering 4.8 million 

 acres in Oregon and 1.2 million 

 in Washington. Stands average 12 

 M board feet per acre in Oregon 

 and 8.8 in Washington, occasion- 

 ally exceeding 30 M feet. The 

 type is remarkably pure, averaging 

 94 percent ponderosa pine in Ore- 

 gon and 92 percent in Washington. 

 Stands are characteristically un- 

 even-aged and open, with little 

 heavy underbush. The ground 

 cover is chiefly grass or low shrubs. 

 Originally a virgin forest of this 

 type extended the length of Ore- 

 gon along the east slopes of the 

 Cascade Range from within a 

 few miles of the summit to the 

 desert's edge. From about 10 miles 

 in width on the north it ranged to 

 nearly 100 miles on the Klamath 

 Plateau in the south, interrupted 

 only by comparatively small open- 

 ings of nonforest land. Extensive cutting from 

 Bend south has broken it up with large areas of 

 pine second growth, but unbroken virgin timber 

 of 200,000 acres or more in one block still exists 

 in this section of the region. 



There has been less disturbance to the primeval 

 forests in the Blue Mountains but physical char- 

 acteristics of this district have limited the pure 

 ponderosa pine type. Extensive areas in the Blue 

 Mountains on the south slopes and lower north 

 slopes are broken up by nonforested valleys and 

 high ridges occupied by mixed conifer types. 

 Several areas of a hundred thousand acres or more 

 of practically unbroken pure ponderosa forests 

 occur in this territory, however. 



In Washington the type is confined to the lower 



OTHER 

 PUBLIC 



I ' ', " i 



.PINE 



SAW TIMBER 



SECOND GROWTH 



NON- 

 COMMER- 

 CIAL 



NON-RE- 

 STOCKED 



WOOD- 

 LANDS 

 a HARD- 

 WOODS 



Figure 6. — Areas of generalized forest types in the ponderosa pine region in private and 

 public ownership. {With "noncommercial" are included lodgepole pine types 25, 26, 

 and 26 A, as shown in table 3.) 



slopes and narrow mountain valleys of the Cascade 

 Range and the southern foothills and plateaus cf 

 the Colville Mountains. There are few unbroken 

 areas of more than 50,000 acres. 



Ponderosa pine type 20, containing 50 to 80 

 percent ponderosa pine and averaging about 65 

 percent, occupies 1.5 million acres, made up of 

 small areas scattered throughout the larger pure 

 ponderosa pine forests where climatic and topo- 

 graphic conditions favor the intrusion of other 

 species. Common associates of ponderosa pine are 

 Douglas-fir, white fir, California incense-cedar, and 

 lodgepole pine in the south and Douglas-fir, western 

 larch, and lodgepole pine in the north (fig. 7). 



The large pine-mixture type 27 usually occurs in 

 comparatively small areas on north slopes and cool 



17 



