CHAPTER IV. 



SALINAS RIVER VALLEY. 



Extent and position of the valley. — Gradcal slope. — Character of the river — Non-navigability. — Geological character of 

 THE valley. — -Alluvial plain, with terraces or flats. — Natural vegetation and productiveness of. — -Westerly winds in 

 the south of the valley. — Effect upon the climate. — The " gavilan hills. — Structure and disposition. — Point pinos 

 RANGE. — Intrusion op trap through the sandstone. — JIetamorphic effects produced in. — Sandstones of tbb san antonio 

 hills — Structure and fossils of.- — Recapitulation and observations upon the geology. 



The valley of the Salinas river is a plain of great extent, being almost 100 miles long and 

 in places nearly 20 miles wide, in general narrowing as it advances southeast, until in 

 places it is not more than half a mile in breadth. Its northern portion lies in Monterey 

 county, stretching, as it advances south, into San Luis Obispo county. Like the Santa Clara 

 valley, it is also of a triangular shape, presenting its base N.N.W. toward Monterey bay, upon 

 which it opens without any intervening ridge, the slope of the valley being so slight and its 

 surface so much depressed at the level of the tide that much of the low land is swampy and 

 overgrown with tule, rush, willows, and marsh vegetation, through which the river lazily winds 

 its way, forming small lagoons, from not having force enough to sweep its waters into the bay. 

 The lower 60 miles of its course is over the gradual slope of the plain, which does not exceed 

 20 inches to the mile, so that its waters arp easily arrested ; further up, south of San Miguel 

 mission, where the valley narrows and the river in places cuts throu^ a granitic region, its 

 fall becomes more rapid ; owing to this slight momentum, sand bars are heaped up by the ocean 

 at its debouche into the bay, which completely destroys its navigation. 



It is not possible to navigate this river far up, the depth, 40 miles from its mouth, being 

 under three feet in its deepest part, where its width might be nearly 100 yards ; but when it is 

 considered that this is the only river in the southern section of the State which does not caiion 

 through mountain passes to reach the ocean, and which rolls through an extensive and fertile 

 valley, no doubt, as the population fills in, some efforts will be made which will both free the 

 bars from its mouth and narrow the area covered by the lagoons and marsh in the lower 15 

 miles of the plain. 



The whole valley may be described as an ancient alluvium derived from the degradation of 

 the granitic, serpentine, chloritic, and sandstone formations, which go to form the mountains 

 on either side ; above this alluvium, and intermingled with its upper layers, is the modern 

 detritus and fluviatile additions. But how little has been accomplished by modern action in 

 either denuding or covering up the ancient alluvium, is evinced by the smooth surface of the 

 plain, running even up to the base of the hills, and by the remains of the terraces, both upon 

 the valley surface and upon the edges of the hills a few yards above the present base. 



The lower 60 miles of this valley is not a plain of uniform level, but a series of low, flat 

 terraces which extend in a north and south direction, and require to be ascended when the valley 

 is crossed from west to east. The lower terrace is a fine stifi" clay, occupying the west side of 



