

V 



128 NEW TEACKS IN NOETH AMERICA. ** 



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passes around tlie southern extremity of the great mass ol 

 mountains which, riuming northward, form the eastern mail 

 chain of the Eocky Mountains. This southern extremity 

 may he considered to be about sixty miles broad; it is 

 drained on the south and south-east by the heads of tlf 

 Pecos, and on the west and south-west by the Santa Fe and 

 Galistco branches of the Eio Grande. 



As we wound about, following the course of the little 

 valleys, and crossing the lowest parts of the ridges betwetf 

 them, we remained neajly always at an eleyation of from 

 6,000 to 7,000 feet. Although we were nominally in the 

 mountains, the reader must not imagiae that our route lav 

 amongst Alpine scenery, witli great peaks towering up ^ 

 the sky, and lofty ranges forbidding our advance, 

 ranges or sierras, on tlie contrary, are here short and irregul 

 spnrs from the main chain of mountains, and not mountaioa 

 themsolyes : they have distui'bed the overlying strata whic^ 

 in the form of mesas, — flat-topped masses of sedimentary 

 rocks, — cover most of the country, and add much grotesqiiB 

 beauty to the landscape. Sometimes their walls are of gi 

 sandstone, at other times of deep red. They are oft 

 much variegated with masses of blue clay, and many 



capped with an outflow of pillared basalt. In some plao 

 we look doT^-n over a district which seems to have sunk to 



low level, containing its own mesas, of different colours, a 

 bounded by the walls of higher ones on either side. T 

 eastern slopes, of all the irregularities, whether they be sie: 

 or mesas, are always more gradual than the western, a 

 are generally more thickly covered with vegetation. Pr 

 bably both facts arise from the same cause — a greater averag 

 rain-fall. 



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Frequently we passed through very fine bodies of pii^ 



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