44 GENERAL DESCRIPTION OF THE COUNTRY. 



system 



been produced by a succession of 



forces analogous to each other in direction, but differing in intensity and occurring at long 

 intervals. The prevalence of granite and other unstratified rocks throughout the Sierra Nevada 

 suggests the ijrohability of its being the oldest of the western range of mountains. The identity 

 of its rocks, generally, witli those of the Alleghany mountains, marks these two distinct and 

 detached chains as probably contemporaneous. The rocks marking these mountains are of the 

 description commonly traversed by gold and copper veins, as is the case in Oregon, California, 

 Virginia, and North Carolina. Travelling eastward from the Pacific along the bed of the G-ila, 

 we encountered similar rocks in a chain of mountains as far east as the Pimo villat^e. This 

 chain, characterized also by the presence of gneiss, mica, and talccse slate, has been traced as 

 far south as the present boundary, where it crosses the Santa Cruz river, between longitude 110 



mines, irom 



the operators had been driven by the Apaches. 



Pursuing our course eastward along the boundary from the meridian of 110^, we cross the 



mountains 



m 



same formatio 



me 



my 



and immense masses of conglomerate, or breccia. Precisel 

 caiion of the Gihi, some distance to the north, about the 

 reconnoissance of 18J:6, Disappointment creek. And no doubt, when future surveys shall 



geography of the country, each of these 



south. With the present 



develop a more minute 

 rantres of mountains wi 



In no country has 



information, I shall not even attempt to connect them conjecturally. 



Hypothetical geography has proceeded far enough in the United States, 

 it been carried to such an extent, or been attended with more diastrous consequences. This 

 pernicious system was commenced under the eminent auspices of Baron Humboldt, who, from 

 a few excursions into Mexico, attempted to figure tbe whole North American continent.* It 

 has been followed by individuals to carry out objects of their own. In this 



peed 



las come t( 

 g on mule 



in suspense upon the subject of the proper route for a railway, and even a preference created in 

 the public mind in favor of a route which actual survey has demonstrated to be the most 



routes 



On the same 

 and ensrraved 



Con 



home 



from 



parallel, west of the Eio Grande. 



ad, while the substantial contributors to accurate 

 1 distorted, and themselves overlooked and forgotten; 

 of which is given from the Alamo Hueco springs 

 about three leagues north of the parallel 31°. 20, 

 most formidable appearance of any range^ on that 

 are called, in Sonora and part of Chihuahua, the 



feierra Madre mountains, yet they do not fulfil entirely the conditions implied by that term, 

 for I am credibly informed that the waters flowing from their base towards the Pacific coast 

 often take their rise to the east of these mountains, and flow through chasms impassable for 



men 



cascades 



sublime 



