26 
CONCLUSION OF THE OFFICIAL REVIEW, ETC. 
San Pedro, a favorable route was found for nearly the entire distance. The valley of the San 
Pedro proved to be wide and open, presenting no impediment to a rail or wagon road. There 
was an abundance of water, grass, and excellent soil, but no growth suitable for timber, though 
sufficient for fuel. Twelve miles from the mouth a large tributary was encountered, coming in 
from the east, and a party was organized for its examination. This party, descending the San 
Pedro for 35 miles from the Quercus canon, crossed the mountains on the right bank to the 
plains west of Mount Graham, and, pursuing a northwesterly course for 36 miles, found the 
head of the “Aravaypa,” as the newly discovered stream was called. The springs mentioned 
by Nugent, in his notes of Hay’s trip, were found in the Playa de los Pimas, and a reconnais¬ 
sance was made of Nugent’s pass. The main detachment passed through the Puerto del Dado 
and the smaller through the wide pass,* between the Chiricahui mountains and Mount Graham; 
the two uniting on the Rio Sauz, about 15 miles below the Cienega. Examinations made east¬ 
ward, across the Peloncillo (Sugar Loaf) mountains, resulted in the discovery of an excellent 
pass for a railroad in a more direct line than that of the route of 1854. From this range of 
mountains an easterly course was pursued, and connexion made with the former survey about 
15 miles west of the point where Colonel Cooke’s emigrant road diverges to the southwest. 
The route between the Rio Grande and the Pimas villages may be divided into three parts— 
from the Rio Grande to the Valle del Sauz ; from the Valle del Sauz to the mouth of the San 
Pedro ; and from the mouth of the San Pedro to the Maricopa wells. 
First division. From the Bio Grande to the Valle del Sauz. —From the Rio Grande the line 
ascends the mesa on the right bank by a grade of 60 feet per mile, and pursues a nearly direct 
westerly course, passing north of Sierra Florida, and 12 miles south of Cooke’s spring, crossing 
the Mimbres bed 21 miles below the sink of the water, and passing through the lowest points 
of the great depression which characterizes the plateau of the Sierra Madre upon this route. 
The summit of the plateau is crossed near Cooke’s emigrant road. The line then proceeds due 
west to the Sauz valley, through a pass in the Peloncillo range, (Sugar Loaf,) about 4 miles south 
of the Sugar Loak Peak. The maximum grade upon this division is 64.4 feet per mile. The 
mean elevation of the plateau is about 4,400 feet above the sea. The summits of the Florida 
pass, of the Sierra Madre, and of the Peloncillo pass, are, respectively, 4,600, 4,600, and 4,481 
feet above the sea. The maximum grade (64.4 feet) is from the Peloncillo summit to the Sauz 
valley. 
Second Division. From El Sauz to the mouth of the San Pedro. —From the Sauz the line is 
projected through the Railroad pass—the wide opening between the Chiricahui and Pinaleno 
(Mount Graham) ranges—thence, northwesterly, along the Pinaleno plain to the Aravaypa 
valley ; down this valley to the San Pedro and to the Gila. The summit of the Railroad pass 
is 4,600 feet above the sea—582 feet lower than the Puerto del Dado—and is without doubt 
several hundred feet lower than any other pass through this range of mountains, south of the 
Gila. The Pinaleno plain has a mean elevation of about 4,400 feet. The descent of the 
Aravaypa to the canon through the Calitro mountains is about 40 feet per mile, for 31 miles; 
tbe grade through the canon and the San Pedro is 60.3 feet per mile, and thence to the Gila 
14.4 feet per mile. 
Third Division. From the mouth of the San Pedro to the Maricopa wells. —This division 
passes along the valley of the Gila, and presents a favorable location, except at about four 
points where salient spurs obstruct the stream. These are thin, and can be easily removed by 
* Railroad pass. 
