4 
GENERAL DESCRIPTION OF THE COUNTRY. 
opening between the Chiricahui range and Mount Graham. Uniting in the Valle del Sauz, the 
country in advance was reconnoitred with reference to obtaining water, under the Peloncillo 
(Sugar Loaf) ridge immediately to the east of us. Receiving a favorable account, we moved 
next morning to this point, determining at the same time the barometric altitude of the gap 
south of camp. 
From the Peloncillo camp we continued eastward, following the trail of the Boundary Com¬ 
mission, crossing a, play a turning the north end of the Pyramid ridge, crossing a second playa 
and ascending the foot slopes of the extreme southern spurs of the Burro mountains, and 
reached the southern emigrant road, (Cooke’s.) We then entered the arroyo, or canon, leading 
from the Ojo de Inez, and ascending it a mile or two to Las Penasquitas, encamped at some 
water holes or natural cisterns in the bed rock of the lateral canons ; proceeded thence to the 
Ojo de la Vaca, Rio Mimbres, and Cooke’s spring, making at the same time lateral examinations 
to obtain barometric readings at stations on lower ground to the south, and of course more favor¬ 
able than that passed over by the wagon road. Thence to the Rio Grande, at Fort Fillmore, 
we followed the usual wagon road, diverging, however, near the edge of the mesa , and descend¬ 
ing to the river bottom by a smooth and easy slope, and avoiding the rough canon heretofore 
encountered north of El Picacho, the examinations of 1854 being most satisfactory, and also 
impossible to be improved upon. 
The observations taken during this examination and survey embraced not only those necessary 
to determine the practicability of constructing a railroad through the country traversed, but 
also, so far as means and time would permit, those required to make a topographical sketch of 
the country along and adjacent to the proposed line. These embraced, therefore, astronomical 
and barometrical observations, in connexion with odometer and prismatic compass surveys in 
the valley and plain districts, and also compass and chain and level surveys in the mountain 
passes. 
Section 1. EXTENT OF SAN FRANCISCO AND LOS ANGELES DIVISION. 
Exploration for railroad purposes in a country whose detailed topography is so little known 
as is that of the great west, involves the necessity in nearly every instance of primary recon- 
noissance to develope the topographical features of the district, that the parent mountain 
chains and radiating spurs with the interlocking rivers and tributaries may be accurately 
mapped, and thus afford definite data with regard to the gaps and depressions in the several 
watersheds or divides, and their lines of easiest ascent and descent. This necessity we found 
to be particularly the case in the California division of our work, where we had reason to expect 
greater accuracy in existing maps, the country along and adjacent to our line of examination 
being for a long period occupied, but by a population who knew, as a general thing, little of 
their own country beyond their ranchos and lines of communication to the neighboring towns. 
Our operations were, therefore, confined in the first place in collecting materials for an accurate 
mapping of the country, and then to determine the question of practicable location of a railroad 
through its various valleys and mountain passes from San Francisco to Los Angeles. The 
explorations and surveys, together with the various side explorations, extend throughout the 
diagonal of the area bounded by the parallels 34° and 37° 30' and the meridian 119°, 123°, 
and have resulted in the location of a practicable route from San Francisco to Los Angeles, 
lying wholly to the west of the watershed of the Coast^Range, and following in the main what 
is known as the coast road. 
