228 Adventures in Scenery 



from Mexico. At the north it is represented by the San Jacinto 

 Mountains on the east and the Santa Ana Mountains on the 

 west. The transverse ranges, San Gabriel and San Bernardino, 

 lie in a generally east-west direction and form a sort of division 

 line between the north and the south. South of the San 

 Gabriel Range is the Los Angeles Basin. The San Gorgonio 

 Pass is a sunken valley lying immediately south of the San Ber- 

 nardino mountain range. The San Andreas fault extends 

 through the San Gorgonio Pass, marking the south wall of the 



Photo by W. S. W. Kew, U. S. Geol. Survey 



FIG. 71. Little Tujunga Canyon, Los Angeles County. Eroded slope of 

 San Gabriel Mountains. 



San Bernardino Range and passes northwestward through 

 Cajon Pass to San Francisco and beyond. The Peninsular 

 Range is represented in its northern portion by the San Jacinto 

 Range, extending north-northeast and cut off by the San 

 Andreas fault, and the Santa Ana Range, extending in a north- 

 west direction 2 5 miles from the Pacific Ocean and terminating 

 in the Puente Hills in the Los Angeles Basin. Between the San 

 Jacinto and Santa Ana ranges the surface is broken by plateaus, 

 the highest of which rise above 2,500 feet, with broad valleys 

 intervening with elevations as low as 1,200 feet. The Penin- 



