MOUNTAINS; MINING; FORESTRY 



209 



stemmed and of brilliant color, so that where there is any 

 soil, the ground is covered with a variegated carpet. But 

 these plants are, like trees, adapted to their surroundings 

 and are not found beyond certain elevations. The summits 

 of high mountains, even when not snow-covered, are often 

 destitute of life. 



High mountains furnish an obstacle to wind and thus 

 affect the climate. Winds blowing from the ocean are moist 



FIG. 108. TIMBER LINE, PIKE'S PEAK 



How do you account for the fact that pine trees are found higher up 

 the mountains than other kinds of trees? 



winds. As they meet a mountain range, the air rises; it 

 is then cooled and the vapor condenses. Rain or snow falls 

 on the slope toward the ocean, and a dry wind passes over. 

 The western slopes of the Sierra Nevadas are well watered; 

 the plains to the east are deserts. 



232. Forests and Forestry. With the exception of a 

 few forest-covered plains in the northern states, the moun- 



