688 TRANS-PECOS TEXAS. 



to say where the beginning or the end of the chains and groups is, or whether 

 they belong to one and the same system. 



All that may be said is, they are built up of igneous (plutonic and volcanic) 

 rocks and more or less metamorphosed limestones, sandstones and shales. 



From the few inhabitants of these counties, which cover thousands of miles, 

 no information can be had except perhaps as to a trail or water hole. 



