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meters, and from north to south 350 kilometers. Southern Cali- 
fornia covers an area somewhat greater than the entire State of 
Pennsylvania. If placed on the northern Atlantic coast it would 
extend east and west from Boston to Buffalo, and southward as 
far as Philadelphia. 
e topography is broken and irregular, with numerous moun- 
tain ranges separated by narrow passes or valleys of greater or 
less extent. The main axis of these mountains lies generally 
parallel with the coast at a distance of 40 to 120 kilometers inland. 
At intervals of 60 to 100 kilometers narrow passes divide this axis 
into several rather distinct sections. Of these sections the north- 
ernmost, which lies between Tejon and Soledad Passes, is composed 
of a series of comparatively low, chaparral-covered mountains, 
the culminating peak of which (Liebre Mountain) is only 1737 
meters, above the sea. South of Soledad Pass, between it and 
Cajon Pass, are the rugged peaks of the San Gabriel Mountains, 
which rise abruptly out of the coastal valleys to altitudes ranging 
from 1800 to over 3000 meters (Mount San Antonio =3024 meters). 
The San Bernardino Mountains, although less broken and irreg- 
ular, reach even higher altitudes. In this range, which is separated 
y the narrow Cajon Pass from the San Gabriel Mountains, is 
the highest mountain south of the Sierra Nevada (San Gorgonio, 
3428 meters). Extending southeastward from Mount San Gorgonio, 
at a much lower altitude, are the desert ranges, the Cottonwood 
and the Chuckawalla Mountains, which separate the Mohave 
and the Colorado Deserts. To the southward, again, between 
the Colorado Desert and the coastal region, rise the San Jacinto 
Mountains. The eastern base of Mount San Jacinto, the highest 
peak in this range, rests almost directly upon the low depressions 
of the Colorado Desert (Palm Springs, altitude 137 meters) while 
its summit, scarcely eight miles distant in an air line, rises with an 
almost sheer ascent to 3242 meters. South of the San Jacinto 
Mountains are the less rugged Palomar, Santa Rosa, and Cuia- 
maca Mountains. This series of mountain ranges divides the 
deserts from the coastal region, and is one of the principal factors 
which influence the climate of southern California. 
The arid desert country east of the mountains, comprising over 
one half the entire area of southern California, is separated by the 
Cottonwood and Chuckawalla Mountains into two distinct 
divisions, the Mohave and the Colorado Deserts. 
