42 CONCLUDING REMARKS. 
Great Basin, when we can, without difficulty, reach the base of the Sierra at any desired point. 
Of all the passes surveyed in the Sierra, the Tah-ee-chay-pah Pass has been found to be the 
best. Going then from New Pass, in nearly a direct line across the Basin, to the entrance of 
Tah-ee-chay-pah Pass, we cross the Sierra, and enter the Tulare valley. From the head of this 
valley to the navigable waters of San Francisco bay, we can descend at once without a single 
obstruction, for it is not at all necessary to follow the route taken by our wagon-train, crossing 
Livermore’s Pass; but it is preferable to follow the shorter route, going at once to near the 
mouth of the San Joaquin river, and thence along the shores of Suisun bay to Martinez, thus 
avoiding all mountains. But this road does not lead directly to San Francisco. In order to 
reach that city it will be necessary to cross the Coast range again. This range has never been 
instrumentally explored, exeept at one or two points; but there is very little doubt but that it 
may be crossed at Pacheco’s Pass, or in its vicinity ; in which case the road would enter the 
valley of San Juan, from which, passing through the San José valley, and along the shores of 
San Francisco bay, it may be brought into the city itself. The distance from the mouth of the 
Gila to Martinez by the route indicated would be 680 miles, and to San Francisco by Pacheco's 
Pass about the same distance. 
To reach San Diego from the mouth of the Gila the road would have to go through the pass 
of San Gorgonio, and along the coast turning the mountainous country which lies to the south ; 
for Warner's Pass presents so many difficulties that, in my opinion, it can never be used for a 
railroad route. The distance to San Diego by the San Gorgonio route would be 315 miles. 
Should the road, instead of being built to the mouth of the Gila, strike the Colorado higher 
up, and, crossing the Basin, ascend the Mohave river, to reach San Francisco it would leave 
that river 25 miles below the point where the Spanish trail strikes it, and from thence follow à 
direct line to the entrance of Tah-ee-chay-pah Pass. 
CONCLUDING REMARKS. 
Accompanying this report are tables giving the data from which the profile of each pass was 
made, and the result of the calculations; also a profile of each pass, and four maps. Asa 
minute survey of the Tejon Pass and the Cañada de las Uvas was made, I have made a separate 
map of each of these passes, on a large scale, accompanied by a double profile—the one obtained 
from barometric measurements with the level. I have made also a separate map, to include all 
the passes in the Sierra Nevada, from Walker's Pass, on the north, to the Coast range. T i 
portion of the country was thoroughly examined. The general map, including the whole 
route, from Benicia to Fort Yuma and San Diego, is on two sheets. I have refrained from 
putting anything on this map that was not positively known, and it is chiefly the result of my 
own examinations. I am indebted, however, to the notes of Captain W. H. Warner, for 
information converning some portions of the Coast range. Captain Warner had been engaged 
for two years in surveying in the lower part of California; and, had he lived, doubtless would 
have produced an excellent map of that portion of the country. As it is, his notes have never 
been compiled. I consider these maps, profiles, and tables to constitute my report. In these 
everything is presented in a concise form, and what I have written is merely a translation iato 
words of what is here expressed in numbers and drawings. 
The instruments for astronomical observations which I had, were a sextant, made by Gambey, 
of Paris, and two large chronometers, one by Charles Frodsham, No. 1961, the other by Dent, 
No. 2057. Observations were taken as frequently as circumstances would admit, numbering 
