MESAS AND FOOT-TIILLS 



203 



that one meets with in the plateau region are 

 not of the same make-up as the clay buttes of 

 Wyoming or the gravel hills of New England. 

 They have a core of rock within them and are 

 nothing less than washed-down foot-hills. You 

 will often see a chain of them receding from the 

 range toward the plain, and growing smaller as 

 they recede, until the last one is a mound only 

 a few feet in height. They are flattening down 

 to the level of the plain sinking into the 

 sandy sea. 



Usually the lomas are seen against a back- 

 ground of dark mountains of which they are 

 or have been at one time a constituent part. 

 For the lomas are the outliers from the foot- 

 hills as the foot-hills from the mountains proper. 

 They are the most worn because they are the 

 lowest down in the valley in fact the bottom 

 steps which receive not only their own wash but 

 that of all the other steps besides. The moun- 

 tains pour their waters and loose stones upon 

 the foot-hills, the foot-hills cast them off upon 

 the lomas, and the lomas in turn thrust them 

 upon the plains. But the casting off effort be- 

 comes weaker at each step as the sides of the 

 hill become less of a declivity. When the little 

 hill is reached the sand-wash settles about the 



Worn-down 

 mountains. 



The moun' 

 tain-wash 

 and its 



