Vol.1] Hall. — Botanical Survey of San Jacinto Mountain. 7 



It is thus seen that the only counection between the montane 

 flora of San Jacinto with that of other mountains must be by 

 way of the San Bernardino Range, from which it is separated by 

 the deep but narrow San Gorgonio Pass. 



Topography. 



Coming now to the mountain itself, it is seen that the main 

 body lies in a north-and-south direction, culminating in a high, 

 ridge-like mass, a mile and a half long on the summit, the 

 northern end of which is capped by the main San Jacinto 

 Peak, the other by Marion Peak. On the west side the descent 

 is at first quite rapid, but the slopes, much cut by carious 

 and ridges, soon become less steep and extend to the North 

 Fork of the San Jacinto River, beyond which the numerous 

 foot-hills become graduallj' smaller and smaller until the plains 

 are reached. On the east a rapid descent is made for some 2000 

 feet, when the slope becomes more gradual and the east-aud-west 

 ridges so round themselves as to enclose two important areas, 

 namely. Round and Tahquitz Valleys, which thus form an 

 immense terrace on the side of the mountain. Below these 

 valleys, and at altitudes of from 6000 to 9000 feet, the slope drops 

 abruptl}^ off to the Colorado Desert, the fault on the northeast 

 side being 8000 to 10,000 feet high. 



Even greater than the contrast between the east and west 

 sides is that between the north and south. Standing on the 

 main peak one may look down the steep north slope to the 

 western arm of the desert only a few miles away, while to the 

 south the mountain is continued in a series of irregular ridges 

 with Tahquitz Peak rising to an altitude of 8826 feet as the most 

 prominent feature, and Santa Rosa Peak rising to 8720 feet in 

 the continuation of the range twenty miles to the southeast. 

 At middle altitudes of the south side are numerous valleys of 

 more or less importance, ranging in size from those only a few 

 acres in extent to the Thomas Valley with its area of nearly 

 4000 acres. 



The canons, on account of the changes produced in the 

 climatic and other conditions by their presence, are of consid- 

 erable importance. The south and west sides are much cut by 



