Hercules Historical Society

Estuary, Watershed and Shore

Human and natural history is shaped by water. The San Francisco Bay Estuary is the largest on the Pacific coast of the Americas. San Pablo Bay is the northern reach of the San Francisco Bay connects the Central Valley with the Pacific. 

San Pablo Bay was a dry valley until land movements and sea levels filled the bay to the shoreline we know today. 

The watershed of Refugio Creek is the land between the Pinole Ridge of hills on the southwest and another, unnamed ridge on the northeast. Defined by low ridges of the Briones Hills descending into San Pablo Bay, the watershed of Refugio Creek extends about three miles southeasterly to an elevation of about eight hundred feet.  

San Pablo Bay

042 1850 Rumsey - San Pablo Bay.jpg

Stand at the mouth of Refugio Creek, look north, and take in the view of ten miles across the 90...


Refugio Valley

301 A glaze house - view from hill.jpg

Refugio is one of several creeks draining the low hills of Contra Costa into San Pablo Bay. It flows for...

Bay Shore


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