CHOROGRAPHY. 5 
Pajaro valleys are separated from each other by hills not more 
than two hundred and fifty feet high; and the valleys of the 
Pajaro and the Salinas open into each other. So also the 
divide between San Ramon and Amador valleys is so low as 
to be scarcely noticed by the traveller; and Amador valley is 
connected, by a level road through a cafion, with Sufiol valley, 
and that by another cafion with the plain at San José Mission. 
North of San Francisco Bay, the valleys of Suisan, Vaca, Pu- 
tah, and Cache Creek, lie castward from Napa valley. The 
valley at the head of Putah Creek is sometimes called Berre- 
yesa valley; and that at the head of Cache Creek, Clear Lake 
valley. North of Russian River there is little level land, and 
that little is found in Eel River valley, about the shores of 
Humboldt Bay, and about Crescent City. 
$4. Coast Rivers—tThe rivers of the Coast Mountains have 
necessarily but a short course. Those south of the bay of San 
Francisco are the San Lorenzo, Pajaro, Salinas, Cuyama, Santa 
Inez, Santa Clara, Los Angeles, San Gabriel, Santa Ana, Santa 
Margarita, San Luis Rey, San Diegaito, and San Diego. Some 
of these are large streams in wet winters; but, in the drought 
of autumn, all those south of the Salinas are swallowed up in 
the sands before reaching the ocean. Most of them are con- 
stant streams to within ten or fifteen miles of their mouths. 
The Santa Ana, the largest river on the southern coast, rises 
in Mount San Bernardino, and is in its nfeanderings nearly one 
hundred miles long, yet only in very wet seasons, once im six 
or eight years, succeeds in getting to the sea. The San Gabriel 
River sinks before reaching Monte, in Los Angeles county, 
and, after passing three miles under ground, rises again. The 
intervening space, where there is no river, is very moist, sandy 
ground, through which the water spreads and soaks. 
W. H. Emory, in his report as member of the Mexican 
Boundary Commission, writes thus: 
“The point at which water ceases to flow is quite variable ; 
its more usual upward limit being marked at or near the pas- 
sage of the stream from the first rocky ranges into the tertiary 
