WATER PROVINCES OF THE UNITED STATES 67 



The Pacific Provinces. Under this term are embraced several 

 sub-provinces, including the Sierra-Cascade, the Central Valley, 

 the Coast Range and the Pacific Coastal Plain provinces. 



The Sierra-Cascade and Coast Range provinces are not unlike 

 the Rocky Mountain Province. Along the Sierra and Cascade 

 mountains considerable moisture is condensed by the high peaks. 

 The water finds its way down the mountain slopes and into the 

 gravels at the base, from which it passes outward into the deep 

 alluvial deposits of the great Central Valley of California, lying 

 between the Sierra and Cascade ranges on the east and the Coast 

 Range on the west. This valley, which is a province by itself, is 

 an important source of underground water. The conditions along 

 the Coast Range are similar to those of the Sierra-Cascade Range. 

 The Pacific Coastal Plain, though developed only in scattered 

 patches, is marked by deposits of considerable thickness and 

 yields much water in southern California, around Puget Sound 

 and elsewhere. 



