(RocRg (pioun^ain ;^oxtetB 



side of this tree. In many places clusters of young 

 trees were growing close to the lower side of the 

 old trees, and were enabled to grow there by light 

 that came in from the side. It may be that the 

 heat from one of the blazing clusters scarred this 

 old pine ; then another young cluster may have 

 grown, to be in time also consumed. But these 

 scars may have resulted, wholly or in part, from 

 other causes. 



Yellow pine claims the major portion of the 

 well-drained slopes, except those that are north- 

 erly, in the middle mountain-zone up to the lower 

 lodge-pole margin. A few groves are found higher 

 than nine thousand feet. Douglas spruce covers 

 many of the northerly slopes that lie between six 

 thousand and nine thousand feet. 



The regularity of tree-distribution over the 

 mountains is to me a never-failing source of in- 

 terest. Though the various species of trees appear 

 to be growing almost at random, yet each species 

 shows a decided preference for peculiar altitude, 

 soil, temperature, and moisture conditions. It is 

 an interesting demonstration of tree adaptability 

 to follow a stream which comes out of the west, 



203 



