CHOEOGKAPHY. 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 caiion, with Sunol valley, 

 and that by another caiion with the plain at San Jose Mission. 

 North of San Francisco Bay, the valleys of Suisan, Yaca, Pu- 

 tah, and Cache Creek, lie eastward from ISTapa 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. — The rivers of the Coast Mountains have 

 necessarily but a short course. Those south of the bay of San 

 Francisco are the San Lorenzo, Pajaro, Sahnas, 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 meanderings nearly one 

 hundred miles long, yet only in very wet seasons, once in 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. Tlie 

 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 



