Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean: Vol. 5, Pt. 2

VALLEYS OF THE COAST M6UINT, NS-GREAT BASIN RANGES.
oay, and the channel eastward to the interior valleys, are broken by projecting headlands, the
ends of ranges which. exhibit an almost perfect parallelism, trending with the main ilnes of
elevation in northwest and southeast lines. A series of parallel coves, or long bays, are formed
by these promontories, and many of the ranges can be traced from- one side of the break to the
other, as at Benicia. The islands of Yerba Buena, Angel island, and others, will be seen to
be in the line of trend of adjoining headlands.
The most extensive valley in the Coast Mountains is that of the Salinas river, reaching'south-ward from the bay of Monterey between the Sierra Santa Lucia and the Gavilan orSalinas
range. Its northern end forms a great part of the shore f the bay of Monterey, and it extends
southwards for sixty miles, and is traversed by the Salinas. It forms one great plain, and in
its lower portions is without the trough-like character common -to the -valleys which -receive sidestreams from the' bordering mountains. Its area may be approximately stated -as 40O square
miles.
The three ranges in the latitude of San Francisco bound'two principal valleys. The most
extensive is that of the bay, occupied in its southern prolongation by the villages:of Santa Clara
and San Jose, and generally known, in its southern portion,'as the valley of San Jose. It is
of con'siderable extent, being over 60 miles- in length from north to south; its southern extremity
connecting with the valley of the Pajaro river, which empties into the bay of Monterey.
The width of the valley between the bases of the mountains, at its widest part, a few.miles
southof San Francisco, is about 15 miles. The -shores -of the bay are low,and alluvial,-and
where;a river enters, they rare deeply indented by long and crooked channels. At the southern
end of:the bay there'is -a wide area of. low, marshy land, which is alternately covered.and left
bar-e' by "the'tides. From this'swampy tract the ground rises almost insensibly to the broad and
plain-like expanse of the San.Jos6 v'alley, remarkable alike for its:delightful climate, the
richness of the,soil,'and its"adaptation to agriculture.
The second valley,rnor rather a series of valleys, lies between the Contra Costa.and Diablo
ranges,"and is'known in its different' parts "as Mount Diablo, Amidor's and- Livermore's valey.
The drainage: of "Mount Diablo Valley is northwards into'Susui-n Bay,"and;of Lve eastward,"i;nt-o the bay- of -San Francisco.
MOUNTAINS OF THE GREAT BASIN:AND DESERT.
The mountains of that part of te Great Basin included within the limits of the State of
California do not form continuous and well-defined ranges like those already described. They
rise in brbkeun and isolated ridges, having a general north and south direction, but distributed
at' intervals over the elevated'surface of the:toasin, -and not characterized by the linear arrangement found to prevail further north. Exception must, however, be made for the eastern ridges
and ranges of the Sierra Nevada, which, in the vicinity of Owens' lake and Walker's lake, trend
in long, lines, and become, in some cases, ranges of the Basin.
A linear disposition of the ranges is also found on'the eastern border of the Basin, where they
unite to forrm a line of mountains,- c'EaIled by Captain Whipple the Pai Ute range, separating the
Basin rrom the valley of the:Colorado. This line'is continuous towards the north from the:mountain of San Bernardino. The Mojave river flows along its western base until, finally, it'sinks
in one of the'lowest valleys. When viewed from the surface of the Great Basin, the chain
appears very much broken-into ridges and isolated conical peaks,;and they are seen-to:be.connected
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