40 ROUTE OVER THE COLORADO DESERT—SAND HILLS, ETC. 
for 24 miles averages 180 feet per mile, and for nearly all this distance the bed is very narrow 
and tortuous, and the rocky hills on either side exceedingly precipitous. In one place the rocks 
have been cut away to afford room for the passage of a wagon. This bed of the creek would 
not answer for the railroad, as in the wet season it is full of water. 
The only other impediment before reaching the desert is at a point where the creek cañons. 
The wagon-road avoids this by passing over a steep hill. For a railroad, heavy side-cuttings, 
and probably a tunnel of a quarter of a mile, would be necessary. Carrizo creek is dry, except 
at occasional points where the water is forced to the surface by rock. There is a constant 
supply of water where it emerges from the hills to lose itself in the desert. The name is 
Spanish, and means a kind of reed. It is applied, in California, particularly to that reed from 
which the Indians collect sugar. 
THE COLORADO DESERT. 
The distance from Carrizo creek to the Algodones, the first point where the road strikes the 
Colorado river, is 803 miles. The whole of this distance is nearly horizontal, offering, topo- 
graphically, not the slightest impediment to the construction of a railroad. The main difficulty 
is the barren nature of the country and want of water. It is believed that the latter may be 
obtained in any desired quantity by digging. Not an inconsiderable portion of this desert is 
below the level of the Colorado river. In 1849 this river broke through its banks, and the 
water flowed inland for some two hundred miles, forming what is known as New river. In 
many places it formed lagoons, while in others it confined itself to a narrow channel. The 
water in the connecting channels having dried up, the lagoons still remain, and are of great 
benefit to the emigrant. 
Near the Colorado, and north of the road, is a strip of country about twenty miles long, 
covered with sand-hills, and these have often been spoken of as a serious obstacle to the railroad. 
From observations made by Mr. Blake, it is shown that these hills may be passed, either to the 
north or south, without diffieulty. The discussion of the character of these sand hills, and of 
the desert generally, appertains more to geology than topography. This subject has been 
treated so ably and fully by Mr. Blake, that it would be superfluous for me to enlarge upon it. 
It is sufficient for me to say that the desert may be considered the least difficult part of a rail- 
way route in California. i 
At the mouth of the Gila the banks of the Colorado are high, and the river narrower than 
its average width. Generally there is a wide bottom subject to overflow, but this is not the 
case at this point, and hence it presents advantages for bridging not frequently found. 
During my return-journey to San Diego I broke the only barometer I had with me, which 
prevented my making a profile from Warner’s to that place, as I had intended. This is the - 
less to be regretted, as the route by the wagon-road on which I travelled is so utterly impracti- 
cable, that it would have been wasting time to have attempted more than a survey with the 
eye. lam aware that many of the ascents and descents may be avoided ; but there are others, 
which offer serious difficulties, which must be encountered. The country between the crest of 
the Coast range and the coast near San Diego is filled with ranges and spurs, and a minute 
reconnaissance would have to be made before it can be mapped with any degree of accuracy. 
The broken and rugged character of the region may be inferred from the annexed sketch taken 
from a hill overlooking the battle-field of San Pasqual. The broad slope bordering the 
mountains and extending to the Pacific is visible in the distance. 
