south of east. Here it is the desert face which is precipitous, 
its base, for the most part, not exceeding 500" (150™) above 
{ sea level, while upon the other side San Jacinto overlooks a 
F confusion of ridges and lesser peaks. 
A main cross-range from San Jacinto parallels the San Ber- 
nardino Mountains at a distance of about forty miles. It com- 
prises the Palomar Mountains+ (summit 5,800", 1,765 ™) and the 
Temescal Mountains, whose terminal summit, Santiago Peak,5 
has an altitude of 5,675" (1730™), and separates the San Jacinto 
Valley from the coast region. 
Further south Cuyamaca Mountain, 6,500* (1,980™) high, 
dominates a rugged region of high ridges and narrow valleys. 
In default of a better name the entire chain, from Tejon Pass to 
Cuyamaca, may be called the Nevadan Range, since it is, in 
truth, a part or a continuation of the Sicrra Nevada. 
1903] FLORA OF SOUTHERN CALIFORNIA 205 
THE DESERTS. 
The topography of the desert region is less accurately known. 
It comprises two distinct divisions: the Colorado Desert and the 
Mojave Desert. The former, stretching southeastward from 
San Gorgonio Pass to the Mexican boundary, is a great valley, 
180 miles (288*") long, and 30 to 50 miles (50-80'") wide. 
In its center it sinks into a deep depression over 253" (76™) 
below sea level,® the. dry bed of what has been in prehistoric 
times first an arm of the sea, and latera fresh or brackish lake. 
In this depressed area, and notably near Salton, volcanic forces 
yet manifest themselves in ‘‘mud volcanoes” and extensive 
solfataras. 
The lower part of this desert, toward Yuma, and in the New 
River region, consists largely of pebble-covered clay plains and 
‘Also known as Smith Mountains. 
5 Sometimes called Saddleback, or Santa Ana peak. In 1861 Dr. Whitney gave 
it the name Mt. Downey, which fortunately has never been accepted. This whole 
range is often called the Coast Range, but it has no connection with the true Coast 
Range of California. 
The following are the altitudes in feet at stations on the Southern Pacific Rail- 
way where it crosses this depression : Seven Palms, 582; Indio, —20; Walters, — 195; 
s Palmas, —253; Salton, —263; Flowing Well, 5; Tortuga, 185. The total dis- 
tance, in a straight line, is about 80 miles (130*™). 
