GENERAL FOREST ASPECTS 



81 



forms alike is of marked interest. In this section the species ap- 

 pear distributed as follows : 



Table 10. Forests of the Coeur d'Alene Section. 



With referenec to the differences of percentage composi- 

 tion and altitude some of the facts are worthy of comment. No- 

 where is the influence of a mountain range more evident. The 

 Coeur d'Alene section as above described is traversed by a water- 

 shed of some 5000 to 7000 feet elevation, extending from north- 

 west to southeast. To the north east flow numerous lesser 

 affluents of the Clark's Fork on the Montana side, to the south- 

 west on the Idaho side the St. Joe and the Coeur d'Alene rivers 

 flow to Lake Coeur d'Alene. This ridge lies squarely across 

 the path of the rain-bearing winds with the result that the pre- 

 cipitation is greater on its western slope. This, together with 

 the greater relative humidity of the lake region supplies the 

 requisite conditions for the growth of the white pine and the 

 species usually associated with it. On the western slope the 

 white pine may reach as much as 36% of the stand, while on 

 the east it is estimated at about 2%. Abies grandis forms 12% 

 on the western slope and a negligible amount on the eastern. 

 Thuja plicata forms 15 % on the western slope, 5% on the eastern. 

 Tsuga heterophylla forms 7% of the stand west of the ridge and 

 a negligible amount on the eastern side. Similarly Engelmann 



