ROUTE NEAR THE THIRTY-FIFTH PARALLEL. 21 
at an elevation of 5,262 feet above the sea, the descent is made to Soda lake, the recipient at 
some seasons of the waters of the Mohave river, 1,117 feet above the sea, with an average 
grade of 100 feet to the mile for 41 miles—the steepest grade yet required on this route. From 
Soda lake the ascent to the summit of the Cajon Pass, elevation 4,179 feet, in the Sierra 
Nevada, is made by following the valley of the Mohave river. The summit of this pass, by 
the line of location, is 1,798 miles from Fort Smith, and 242 from the point of crossing the 
Colorado, Here a tunnel of 23 or 3;4 miles through white conglomerate sandstone is 
required, descending to the west with an inclination of 100 feet to the mile, which grade 
will be the average for 22 miles into the valley of Los Angeles, if the broken character of 
the hills should be found, upon careful examination, to admit of such side location as would 
reduce to that degree the natural grades varying between 90 and 171 feet per mile. Thence 
to the port of San Pedro the ground is favorable for location. 
The principal characteristics of this route, in comparison with others, are, probably, its 
passing through or near more numerous cultivable areas, its more abundant natural supply 
of water as far west as the Colorado, and the greater frequency and extent of forest growth 
on the route between the Rio Grande and the Colorado. These two latter characteristics 
entail a third, however, of an unfavorable nature—the large sum of ascents and descents. 
Near the meridian of 99° the change from fertile land to uncultivable is complete, excepting 
in the river bottoms, which are more or less fertile. Some portions of the upper valley of the 
Canadian, the upper valley of the Pecos, the valleys of the Rio Grande, Zuiii, Colorado 
Chiquito, San Francisco, Colorado of the West, and its tributaries, possess a fertile soil, 
requiring generally irrigation to make it productive. That portion of the southwest corner of 
the Great Basin traversed by this route, and over which the explorations of Lieut. Williamson 
also extended, is well constituted for fertility, its barrenness resulting from the absence of rain. 
Generally the uncultivable plains have an abundance of nutritious grass, though there are 
extensive tracts where little or none is found. 
The route may be considered sufficiently well supplied with good building-stone, since sand- 
stones suitable for the bridge-building required are reported to exist in the generally soft trias 
formation, extending from Delaware mountain, on the Canadian, to the Rocky mountains, 
a distance of 600 miles. 
Forest growth, furnishing timber of size suitable for ties and lumber for railroad uses, is 
found in the following localities: continuously on the route east of longitude 97°; in or near the 
Pecos valley; in the Rocky mountains and Sierra Madre; in the Mogollon mountains, (south 
of the route,) in which the Colorado Chiquito and some of its tributaries rise; on the slopes of 
the San Francisco mountain; and continuously, with short intervals, for more than 120 miles; 
and on the Sierra Nevada. The distances apart of these points of supply are respectively 540 
miles, 100 miles, 150 miles; from the Sierra Madre to San Francisco mountain, 250 miles; 
then for a space of about 120 miles the supply may be considered continuous; thence to the 
Sierra Nevada, 420 miles. If the road be built from the two termini, the greatest spaces over 
which ties, lumber, &c., must be brought by it are 400 and 500 miles. The route, therefore, 
in comparison with others, is favorably circumstanced in this respect. 
The same localities will supply fuel; and, in addition, the coal-fields of Delaware mountain 
will furnish the eastern portion of the route where wood cannot be economically used. It is 
reported that coal exists in severa! localities in the Rocky mountains, both east and west of the 
Rio Grande, near this route, but there is no positive and reliable information that it has 
been found in sufficient quantities for profitable mining. 
The route for 540 miles east of the Sierra Nevada must receive its fuel from the ports of 
the Pacific. 
Over portions of this route, as upon all others, no fuel whatever, not even sufficient for 
working parties, will be found. The greatest distance over which this total absence of 
fuel exists, is between the Colorado and Mohave rivers, 115 miles. 
