CHAPTERV. 



PHYSICAL AND GEOLOGICAL DESCRIPTION OF THE COUNTRY FROM THE 

 INITIAL POINT ON THE PACIFIC TO THE JUNCTION OF THE GILA AND 

 COLORADO. 



The data on whicli these results are based are derived from personal observation and col- 

 lections continuously made during my stay in that region from July, 1849, to March, 1851. 

 This period was variously occupied in different sections of this region, including an interrupted 

 residence in the vicinity of San Diego ; an expedition of three months' continuance to the mouth 

 of the Gila River ; a land journey up the Pacific coast as far as Monterey; a residence during 

 the fall and winter months of 1850-'51 at the Mission of San Luis Rey ; together with various 

 minor excursions to the mountains east, north and south of San Diego. 



The region of country thus covered by my observations includes portions of territory lying 

 between 32° and 36° N. latitude and 114°-121° W. longitude. The district, however, to which 

 my attention was mostly confined is indicated on the accompanying geological map, and popu- 

 larly known under the title of Southern California. 



The separate heads under which I propose to embrace the general information pertaining to 

 the subjects assigned me are — 



I. — The general 2'>hysical features of country. 

 II. — Geology and mineral productions. 



III. — Botany. 



IV. — Agricultural capacities. 



I.— THE GENERAL PHYSICAL FEATURES OF COUNTRY. 



The most marked external feature which serves to give character to the region under exami- 

 nation is seen in the occurrence of a mountain range parallel and in close proximity to the 

 ocean, presenting in its various elevations and the differences which characterize its two slopes 

 (eastern and western) a great diversity of scenery within a small compass of territory. The 

 range itself, in its geographic relations, must be regarded only as an inferior link in the great 

 mountain chain extending along the entire northwest coast to the extremity of the California 

 peninsula. To the part at present under consideration the local but not very precise term of 

 the Cordilleras of California has been applied. 



Directing our attention to this portion of the mountain range, considered as a whole, it will 

 be remarked that, while the general direction of the range is parallel to the coast, this feature 

 is worked out in detail so variously that it would be difficult, from a single point of view, to 

 decide on the true direction from noting the supposed axis of greatest elevation. This is, per- 

 haps, owing to a peculiar feature of the range, which, instead of consisting of continuous ridges 

 or sierras, as they are termed, are made up of an irregular series of rounded or ridge-formed 



