84 NEW TRACKS IN NORTH AMERICA. 
Crossing the Rio Colorado here to Fort Yuma we find | 
 ourselyes in the State of California, and but a short distance | 
from the Mexican boundary. Perhaps a more uninviting 7 
point could not be selected at which to enter the far-fame 1 
State, whose name is synonymous with bullion. From the J 
Rio Colorado to the Cordillera, or Great Range, stretches a ] 
weary desert, 100 miles in width. Traversing this desert, and 
crossing the Mexican boundary, is New River, whose waters 
(when it has any) run northward into vast shallow lakes. It 
is well known that a large part of the desert is below the | 
level of high water in the Colorado, and as New River re- 
ceives its water from the floods of the former, much of this 
land can be irrigated. Here the mirage is seen in great pe - 
fection, often deceiving the weary and thirsty traveller. i 
The eastern drainage of the Cordilleras is marked by 
rapidly-descending cafions, the waters from which find their 
way down the long slopes at the foot of the mountains to t he 
desert, where they soon disappear in their dry sandy beds. — 
The foot-slopes of these mountains ascend from the desert] 
by grades of from 50 to 150 feet per mile. Through these e 
mountains are three passes, accessible for the Gila route, 
viz., Jacomba, Warner’s, and San Gorgonia. The Jacomh 
eee by General W. S. Rosecranz, is the mo 
southern, and almost on a direct line from Fort Yuma to & 
Diego. It would save about sixty miles over the route 0 
Warner’s Pass, but it is deemed impracticable for a railroa i. t 
Warner’s Pass is practicable, but requires the maximum 
grade (116 feet) for several miles, with very heavy and 
expensive rock-work. San ciienia Pass is the best of | 
three, but too far to the northward to be used were Sal 
Diego to be the terminus. Considered with reference to 
route by the 35th parallel, it would be its most direct out! 
