238 OUR FEDERAL LANDS 



in precipitous cliff sides, remains of prehistoric civili- 

 zation of high degree. 



The towering long wall of the Sierra continued 

 northward by the Cascades rob the Pacific winds 

 of moisture which otherwise would have watered 

 the desert eastward to the Rockies, producing on 

 these ranges' western flanks forests of luxuriance 

 and size of species unknown elsewhere. Sequoia, 

 General Grant, Yosemite and Mount Rainier Na- 

 tional Parks conserve magnificent examples of for- 

 ests in unaltered descent from earliest beginnings, 

 while Rocky Mountain, Yellowstone and Glacier 

 National Parks function similarly for the Rockies. 

 Mesa Verde, Grand Canyon and Zion National 

 Parks preserve distinguished examples of desert 

 evolution. 



In many National Parks besides those which 

 specialize in volcanism are many minor volcanic rec- 

 ords, some possessing great interest. Varied gra- 

 nitic forms abound in parks principally sedimentary, 

 and sedimentary forms in parks principally granitic 

 and volcanic. Mountain building and stream forma- 

 tion are illustrated in nearly all, and in all, in magnifi- 

 cent example and infinite range, are masterpieces 

 of the artistry of Nature's marvellously skillful 

 sculptor, Erosion, many of them unequalled in the 

 whole world of scenery. Together, also, they show 

 records of the evolution of life from earliest visible 

 evidence to the living forms of to-day. 



As working laboratories and exhibitions of na- 



