FOR A RAILWAY. 571 
so gradual are the ascents and descents, that they are scarcely 
perceived. After they are passed, broad, open, and level plains 
occur, where for miles very slight embankments or excaya- 
tions will be required for the construction ofa road. 
If, on examination, it is not deemed advisable to cross the 
Rio Grande within the district named, we must then strike it 
about twenty-five miles further south, near San Hleazario, 
thence across the basin of that river to the table-land beyond 
and south of the mountains which lie west of El Paso. Broad 
level plains again occur here without any continuous moun- 
tain chain. 
An idea has arisen that the line of Colonel Cooke’s road is 
a practicable one fora railway. This is a great mistake. That 
road crosses a spur of the Sierra Madre with a descent of from 
twelve to fifteen hundred feet in ten miles, all of which is avoid- 
ed by keeping some ten dr twenty milestothe north. In fact, 
my route with the engineering parties across this district, as 
detailed in this narrative, diverging occasionally a few miles, 
will be found a practicable one. 
The first barrier of consequence, of which I cannot speak 
with certainty, is a range of mountains beyond the San Pedro 
river, bounding the Santa Cruz valley on the east. They termi- 
nate in latitude 31° 15' where our parties passed them. Be- 
tween 32° and 32° 22' they are passed by wagons, but I cannot 
state with what facility. Ifan opening exists any where between 
the 32d parallel and the Gila, the last obstacle to reaching the 
plateau near that river is overcome. Here is an open level plain, 
from one hundred to one hundred and twenty miles across, to 
the river mentioned. In fact, it may be said that when the San 
Pedro Mountains are passed, we shall have an uninterrupted 
plain of about two hundred and fifty miles to the Colorado. 
It will thus appear, that the entire district from the Rio 
Grande to the Colorado, which may be put in round numbers 
at five hundred miles, consists of broad, open, gravelly plains, 
from fifteen to twenty-five miles in width, with scarcely an un- 
