STORY OF OUR NATIONAL FOREST 93 



in the eastern National Forests, notably in the 

 White Mountains, are fragments of untouched for- 

 est which, let us hope, may escape for many years. 



So much for the vast eastern forest. The west- 

 ern forest was scarcely more than a fifth its size, 

 and was located on widely separated mountain 

 ranges and on islands of high plateau in oceans of 

 desert. But it possessed, and possesses, marvelous 

 distinction in the size and grandeur of its conifers. 



You will recall that, between the Rockies and 

 the Sierra lies a vast semi-arid country, and that 

 the western slope of the Cascades and the Sierra is 

 famous for its forest of gigantic trees. The reason 

 is that the latter lofty barrier of mountains robs the 

 warm winds from the Pacific of moisture with 

 which nature meant to water half a continent. 

 Therefore the exuberant fertility of the western 

 slope of the Cascades and the Sierra. Therefore the 

 desert between these ranges and the Rockies. 



As with other crops, forests depend wholly on 

 watering, and in the arid West water depends pri- 

 marily on altitude. Above certain altitudes, varying 

 also with latitude and local conditions, whatever 

 moisture the air contains deposits in dew, rain, and 

 snow while below it aridity prevails. Standing in 

 the most arid part of the great Navajo desert, for 

 example, Navajo Mountain is a forest-crowned pyra- 

 mid, from which cold streams descend to evaporate 

 in the desert. 



So it is that the nation's great western forest 



