NORTH AMERICAN INDIANS 



441 



lar interpretation. It is conceivable that a tribe may build up its cul- 

 ture by some independent inventions and by some borrowing from its 

 neighbors, all of which may perhaps be revealed by the careful analysis 

 of neighboring cultures and a comparative study of their traits. If we 



The Distribution of Forests in Western United States. 



The shaded portions of this map mark the areas originally covered with trees. 

 The true plains extend from north to south along the eastern border of the Rocky 

 Mountains. On the west, trees are found on the sides of mountains ; on the east, 

 they stretch out into the plains along the margins of the streams. Reference to the 

 tribal map shows how the typical group ranges in the open plains while the eastern 

 agricultural village group lives in the partially forested belt. On the west the 

 plateau group appears to range in the open stretches among the mountains. 



apply this method to the Plains we find an easy line of approach. Some 

 years ago, Mr. Mooney published his objective study of the ghost dance 

 religion, a curious religious movement originating in one tribe and 



