ROUTE NEAR THE THIRTY-SECOND PARALLEL. 25 
of the Gila, in a straight line over the Colorado desert, a smooth and nearly horizontal plain, 
requiring but little preparation for the superstructure of a railroad. Thirty-five miles of this 
is a gravel plain; the remainder is alluvial soil, which only needs irrigation to be highly 
productive. On this latter soil, water is found at a depth of 30 feet. 
The steepest natural slope, in ascending to the summit of this valley pass, (elevation 2,808 
feet,) is 132 feet per mile for two miles. 
San Diego and San Pedro can be reached by lines of about equal length from the San 
Gorgonio Pass. To the former, the first section of the route to San Luis Rey (about 75 miles 
long) would pass through a country generally favorable to the construction of a railroad, 
being a plain with numerous hills from 500 to 1,000 feet high, irregularly distributed on 
its surface, between and around which a road may be carried with favorable grades. Between 
San Luis Rey and San Diego, however, about 40 or 45 miles, the coast is cut into numerous 
deep intricate gullies by the drainage of the plain. 
To San Pedro, about 125 miles, the route lies almost wholly over the same description of 
ground as that constituting the first section of the San Diego route, and avoids the obstacles 
presented by the second. It is, therefore, assumed that the terminus of this route should be at 
San Pedro, the point which it has now reached. It may, however, be proper to remark that 
San Pedro is an open roadstead, and would require the construction of a breakwater to constitute 
it a safe harbor. 
From the report of Capt. Pope, it would appear that the belt of fertile land which lies on 
the west side of the Mississippi throughout its length, extends on this route nearly to the 
headwaters of the Colorado of Texas, in about longitude 102°—that is, about three degrees 
further west than on the more northern routes. The evidence adduced in support of this opinion 
is not, however, conclusive; and, until it is rendered more complete, the fertile soil must be 
considered in this, as in other latitudes, to terminate about the 99th meridian. Thence to the 
Pacific slopes the route is over uncultivable soil, though generally grassed, the exceptions being, 
as on the route of the 35th parallel, in aan of the valleys of the Pecos, Rio Grande, Gila, 
and Colorado of the West. The table-lands and mountain slopes are usually well covered with 
grama-grass, and in New Mexico have supported immense herds of cattle. There are excep- 
tions to this, however, on the greater portion of the Llano Estacado, on portions of the plains 
between the Rio Grande and the Gila; and (comprised in that space) from Tuczon to the Gila, 
80 miles, there is no grass on the route travelled, nor is it to be found on the Lower Gila 
valley; occasional patches of bunch-grass only being found on the plain, and a species of 
grama-grass sometimes upon the mountain sides. No grass is found on the Colorado desert, 
135 miles along the line of location. = 
The length of the route through this generally uncultivable soil is 1,210 miles. Upon 
descending from the summit of the San Gorgonio Pass, on the route to San Pedro, the 
soil is fertile, and either well watered or can be irrigated. 
The climate throughout the route is salubrious, the heat due its southern latitude being 
moderated by the elevation of the table-lands. On the Colorado desert it is torrid, but not 
unhealthy, and much of the country west of the Sierra Nevada and Coast range is celebrated 
for health and agreeableness. 
The principal characteristic of this route is the great extent of high, arid, smooth, and 
nearly horizontal table-lands which it traverses, reaching an elevation of 4,000 feet upon 
the dividing ridge between the Brazos and Colorado rivers of Texas, near which elevation it 
continues until it descends from the pass of the Sierra de Santa Catarina to the Gila river, a 
space of nearly 600 miles. The elevation at the summit of the Llano Estacado is 4,700 feet, 
and in the passes of the Guadalupe and Hueco mountains, east of the Rio Grande, 5,700 and 
4,800 feet, respectively. Between the Rio Grande and the Gila, the greatest elevation, which 
is twice attained, is 5,200 feet; the mean elevation, before the descent to the Gila is com- 
-menced, being 4,100 feet. From the eastern edge of the Llano Estacado to the pass of San 
; 4a 
