8 RURAL CALIFORNIA 



a few hundred feet, severing the southern California 

 islands from their shore connections and allowing the 

 Pacific Ocean to fill a shore valley and form the bay 

 of San Francisco and other bays along the coast. 

 Out from the present Pacific beaches of California, 

 there are sharp and deep cliffs in the ocean floor that 

 are believed to be the old shore of the primeval sea 

 when California was in the making. 



Somewhere in geologic time, California assumed 

 a form recognizable as the progenitor of the State as 

 now seen. The Sierra Nevada and its north and 

 south connections dominated its eastern borders and 

 the ridges of the Coast Range looked down on the 

 western ocean. Between the two, covering what is 

 now called the "great valley of California" was an ex- 

 panse of waters that later broke through the Coast 

 Range and uncovered the foothills, the wide valley 

 plains and enabled the great rivers to build up the 

 lower central areas to reclaimable marshes which are 

 now recognized as rich delta regions. While this 

 was going on centrally in the State, glacial sculptur- 

 ing, volcanic outpourings and meteorological agencies 

 were developing topography in the mountain encircle- 

 ment of the great valley which brought the State 

 nearer and nearer to what we now recognize as out- 

 standing local features of hill, mesa and valley areas 

 supporting growth of plants and ministering suit- 

 ably to the higher classes of animal life and later still 

 to the uses of mankind. 



While such changes were taking place and previ- 

 ously submarine activity perhaps had more to do 



