28 
CONCLUSION OF THE OFFICIAL KEVIEW, ETC. 
From station 4 to 
“ ££ 5 
££ « 6 
“ “ 7 
“ “ 8 
“ “ Q 
station 5, 17 miles. 
“ 6, 10 £f 
££ 7, 20 “ 
“ 8 , 21 “ 
“ 9, 28 ££ 
££ 10, 29 ££ 
The supply of timber along this route is scanty. Cedar and pine are found in the Copper- 
mine mountains and near the sources of the Mimhres. The valleys of the Santa Cruz and the 
Gila contain dense groves of mezquite, which, particularly in the former locality, will furnish 
a large number of excellent cross-ties. Cotton-wood in limited quantities is found in nearly all 
the valleys where water-courses exist. There is not timber enough along the line, within fifty 
miles each way, to supply its demands. 
The improvements in the former route made by this survey may be stated in brief to be : a 
more direct railroad line between the Pimas villages and the Rio Grande, with lighter grades, 
fewer summits, less elevation, greater supply of water, avoidance of a long jornada, and the 
introduction of cultivable valleys. It is probable, from the form and geological structure of 
the basins and plains, that ordinary wells may be made to furnish abundant supplies of water 
at distances not too great for the economical working of passenger trains. It has been indicated 
that in some localities artesian wells may be resorted to if needed. 
As a post-route, Lieutenant Parke is of opinion that the route of the thirty-second parallel 
presents many advantages. By the construction of water stations at suitable distances, and by 
providing relays at various points, the mails could be transmitted from the Mississippi to San 
Diego in less than thirty days. 
In addition to the results of his own examinations near the thirty-second parallel, Lieutenant 
Parke presents those of a detailed instrumental survey from the bay of San Diego, through 
Warner’s pass, to the Colorado desert, made by Charles Poole, Esq., civil engineer, under the 
direction of the San Diego and Gila Railroad Company, organized under the authority of the 
legislature of California. Beginning at San Diego, this line ascends the San Diego river to 
San Isabel; passes through the valley of San Isabel and San Jose to Warner’s pass and to the 
Indian villages of San Felipe, and from this point, through a canon, to the desert. The maxi¬ 
mum grade—107 feet per mile—is at the approach to the San Isabel summit. The grades to 
the summit of Warner’s pass are 102 and 106 feet per mile. The distance from San Diego to 
Fort Yuma is 189.1 miles. The whole line is divided into two portions, the prairie and moun¬ 
tainous. Assuming in his estimate that the two are equal in length—stating, however, that 
££ the cheaper is largely in excess”—Mr. Poole says : ££ we have ten miles at the western, and 
eighty-five at the eastern section, to be estimated at the lower rate.” 
The probable average cost of a single mile of the cheaper portion, to put the road 
in running order, including equipment, he estimates to be... $14,615 00 
And for ninety-five miles... 1,388,425 00 
And for the more expensive portion, the cost per mile. 65,085 00 
Which for ninety-five miles is... 6,183,075 00 
Makiug a total of. 7,571,500 00 
These estimates of cost per mile are very much less than those for similar ground in the report 
of Lieutenant Parke, and in other War Department reports. 
