SECTION Y. 
From Rio del Norte to Flax * River , 237.5 miles. 
Bridging the river at San Felipe or at Isleta would not he a difficult operation. Few of the 
principal railroads in the eastern States are without structures of equal magnitude. From the 
point selected, a gentle curve toward the south would enable the engineer to ascend the steep 
slope of the high table-land which divides the Del Norte from Rio Puerco. Thence, passing to 
the latter stream, he would reach its junction with the valley of Rio San Jose, which extends 
westwardly to Campbell's Pass of the Sierra Madre. To this point the grades would be light, 
the maximum being 53 feet per mile. Excellent spruce and pine timber is plentiful upon the 
slopes of Sierra Madre, and may be easily obtained. Material for masonry is also sufficiently 
abundant. 
By the term “ Sierra Madre” is meant—according to Mr. Gallatinf —“ that' ridge which 
separates the waters that fall into the Atlantic from the rivers which empty into the Pacific 
ocean, without any regard to its elevation.” Near the sources of Rio Gila it is a lofty range. 
Below the parallel of 32° 30' the chain is broken, and divided into a series of minor ridges, 
having crests, more or less prominent, extending in the same general north and south direction. 
Near latitude 32° this system is extended to about 3° in width, and the low swelling ridges form 
a succession of basins, without any surface outlet for their scanty supply of waters. Here rains 
are absorbed by the sandy soil, or are evaporated from the mineralized surface of some shallow 
lake. The most favorable passage of the Sierra Madre range that can be found north of the 
head-waters of Rio Gila, is probably at Campbell’s Pass. This, although more elevated than 
those of the Mesilla country, possesses but one crest intervening between the waters of the 
Atlantic from those of the Pacific. It is a wide gap, separating the ridge known as the Zuiii 
mountain from the Sierra de San Juan ; upon the east the waters of Agua Azul flow through 
the open valley of San Jose, and a rill from the spring of Ojo del Oso courses along the gentle 
declivity which forms the Rio Puerco of the west. The great advantages of this pass of the 
Sierra Madre consist in its single summit; in the easy grades by which it may be approached 
east and west; in the convenient positions of springs and streams ; and in its close proximity to 
forests of good timber. 
Westward from this point we have the valley of Rio Puerco of the west, extending in a gen¬ 
eral west-southwest course for 121 miles, to its junction with Flax river ; the average grade being 
about thirteen feet per mile. After leaving the slopes of the Sierre Madre the sylva consist of 
cedars upon the prairies and a few cotton-woods upon the banks of the streams; the pine forests 
of the Zuiii mountains contain an ample supply of timber for this section. 
The main survey crossed the Sierra Madre by the pass of the Camino del Obispo, and thence 
traversed the valley of Zuiii. The following notes relate more particularly to that line. 
The valley of Rio Grande from Albuquerque to Isleta, fourteen miles, is wide and fertile. It 
contains several villages and large haciendas , surrounded with well-cultivated fields, which are 
irrigated by numerous acequias that traverse the bottom-lands. Upon the west it is bounded 
« Flax river is the translation of ‘‘Bio del Lino,” the first Spanish name given to the stream lately known as the Colo¬ 
rado Chiquito. As there are already within our territory many rivers named Colorado, it would seem desirable to with¬ 
draw this from the list. 
-j- See letter of Hon. Albert Gallatin, in Major Emory’s report, Ex. Doc. No. 41, 30th Congress, 1st session. 
