White Pines of Montana and Idaho. 229 



Western Larch. In investigating the yield of White Pine in this 

 region during the summer of 1910, entire sections were examined 

 which were covered with a mixed stand such as described, and 

 which would yield no less than 70,000 feet B. M. per acre. Fully 

 stocked acres of nearly pure White Pine were found which con- 

 tained over 130,000 feet B. M. merchantable volume per acre. 

 This timber was all 140 years old, with an average height of 

 about 130 feet, yielding 6 merchantable logs to the tree; and with 

 an average diameter breast high varying from 14 to 24 inches, 

 depending on situation and density of stand. Larger trees, which 

 have diameters ranging up to 36 inches, height up to 175 feet, 

 and yielding as high as 9 logs to the tree were quite common, 

 however, in the same age classes. This is practically the age at 

 which the yield is the greatest. The trees continue to grow 

 rapidly for 60 or 70 years more, increasing in height and di- 

 ameter, but this growth is usually more than offset by a thinning 

 of the dominant stand, the subdominant cedar and hemlock finally 

 filling up the interspaces. 



Upon the Coeur d'Alene the development is practically as good. 

 The Percentage of White Pine here is greater than that on 

 the Kaniksu, since the species forms a greater proportion of the 

 type. Supervisor Weigle estimates that 40% of the merchantable 

 stand is White Pine. Upon the Pend Oreille the winter type 

 appears to dominate at a somewhat less degree while the species 

 usually forms only from 25 to 50% of the type, the larch again 

 becoming more plentiful. South of the Coeur d'Alene, upon the 

 North Fork of the Clearwater River in the Clearwater National 

 Forest, the species grows in immense bodies, but as one proceeds 

 south it becomes more and more restricted to moist protected 

 basins and stream bottoms of about its middle range in altitude, 

 until on the Nez Perce it becomes reduced to single scattered 

 specimens or patches and finally disappears altogether. 



On the eastern side of the Bitterroot Range in Montana the 

 same condition prevails. Although scattered over a considerable 

 part of the Kootenai River, the white pine type is said by Deputy 

 Supervisor Parker to cover scarcely more than 5% of the total 

 area, while the species only occasionally makes up 25% of the 

 forest type. On the Blackfeet and Flathead National Forests 

 extensive stands of this type are found in Swan River Valley, 

 and the various forks of the Flathead River (particularly the 



