MOUTH OF SAN PEDRO TO PIMAS VILLAGES. 
27 
agreeable to the taste. About two miles below these springs water rises in tbe bed of tbe stream, 
forming a cienega, and is probably the source of the running water found below. 
On the eastern slopes of the Sierra de Calitro there are several springs of a limited capacity, 
such as Pheasant, Antelope, and Dove springs. These sources are probably too far from the 
projected route to be of any avail for supplying locomotives. By a divergence, however, 
these may be brought into requisition. For working parties on construction, or to emigrants 
who may take this route, or are desirous of recruiting their animals, or troops on scouting 
expeditions, the Calitro mountains present many advantages; permanent water exists in 
many places near the plain. The slopes are covered with a luxuriant growth of grama grass, 
and the gulches are filled with oak, ash, and walnut timber, the whole appearance of the country 
strikingly resembling many localities among the Coast Range of California, the wild oat being 
replaced by the grama grass. Game is also abundant—antelope, black tailed deer, and a species 
of grouse, having been seen there—as the names given to the several springs imply. 
The relative length of these two routes is as follows : the one eighty and one-quarter miles, 
and the other one hundred and ten miles from the summit of the Railroad Pass, a difference of 
twenty-nine and three-quarters miles in favor of the Aravaypa route. The maximum grade 
upon the Nugent's pass route is one hundred feet per mile, and on the other sixty and three- 
tenths feet per mile. Nugent’s pass is also two hundred and eighty feet higher than the Rail¬ 
road Pass and the average surface of the Pinaleiio plain. The localities for water are nearly 
equal on both routes. These items are sufficient to demonstrate the superiority of the Aravaypa 
route. 
Section 4. 
Third Division. —From the mouth of the San Pedro to the Pimas villages .—This division lies 
solely in the valley of the Gila, and may be subdivided into the upper or gorge division, and 
lower or plain division. A short distance below the mouth of the San Pedro, the Gila com¬ 
mences to flow westward, and in so doing encounters and pierces the axes of upheaval, pro¬ 
ducing short canons or gorges, separating the valley portions above and below where the side 
hills recede, and give slopes more favorable for locations. The river bed varies in width 
according to the locality, occupying in the gorges the entire bottom, while in the open portions 
it spreads out over an area from fifty to one hundred yards wide, and is made up of a single channel 
or stream, during ordinary stages of water, together with a number of side drains, which, from 
the drift wood, sand, and cobble-stone beds, are evidently overflowed, either during the season 
of rains or on the melting of the snows on the mountains near its sources. The water was clear 
and palatable, flowing with a moderate current over an alternating bed of sand, pebbles, and 
rock. The stream was, in July, about twenty feet wide and twelve inches deep. Its banks were 
fringed throughout with cotton-wood and willow thickets, with mesquite at the base of the 
terraces. 
Below the gorge division, the valley opens out in a broad plain, increasing in width as the 
Pimas villages are approached. This bottom is covered with dense groves of mesquite, with 
occasional intervening patches of grass, which, however, become less frequent as the river is 
descended. 
Starting then from the mouth of the San Pedro we have sixty-three miles to the Pimas villages, or 
rather to the point (Camp 69) where the survey of 1854 leaves the river, and a difference of 
elevation between these points of 749 feet, giving, therefore, an average descent of 11.9 feet per 
