16 MINERAL CHARACTER OF THE COUNTRY. 



the last thirty miles we have observed a range of sand-hills, from ten to 

 thirty feet high, which appear to have been thrown up by the winds, 

 and support a very spare vegetation of weeds, grape-vines, and plum- 

 bushes. Upon the river the timber has diminished so much that we 

 now find only here and there a few solitary cotton- woods. 



From the fact that the Witchita mountains are composed almost 

 entirely of granite and other silicious rocks that usually accompany 

 metallic veins, and that in many places along the range they bear evi- 

 dent marks of great local disturbance, and from the many detached 

 specimens of copper ore found upon the surface throughout this region, 

 I have no doubt but that this will be found, upon examination, to be a 

 very productive mineral district. 





