Geologic Trips, Fort Funston

Ocean Beach

 

The sand that now forms Ocean Beach made its trip through the Golden Gate during the last ice age, when sea level was a couple of hundred feet lower, about 10,000 to 15,000 years ago. At that time, the Sacramento River flowed through the Golden Gate and continued west for another 20 miles before it reached the shoreline of the Pacific Ocean. Large quantities of sand were carried from the Sierras by the Sacramento River and deposited to form beaches and dunes along this old shoreline. As the glaciers melted, sea level rose and the shoreline, beach sand, and sand dunes moved eastward with the rise of sea level. Ocean Beach represents the present location of this shoreline.

 

Most of Golden Gate Park and much of northern San Francisco were built on dune sands blown eastward from Ocean Beach.

Related Links

Geologic background: Fort Funston (pdf)

Geologic trips: Fort Funston Bluff Ocean Beach

 

Exterior Websites

Golden Gate National Parks Conservancy: Ocean Beach

Wikipedia: Ocean Beach, San Francisco

Ocean Beach, looking south from the Cliff House toward Fort Funston.