Oakley in Contra Costa County, California — The American West (Pacific Coastal)

Carquinez Strait

Photographed By Andrew Ruppenstein, January 13, 2022

1. Carquinez Strait Marker

Inscription. Corcoran Lake filled the Central Valley 760,000 years ago (including where you now stand)! It drained to the ocean at today's Monterey Bay. Tectonic forces plugged the outlet and tilted the lakebed to the north 200,000 years later. The surging lake overtopped the East Bay hills and carved a new drain – today's Carquinez Strait.

Carquinez Strait funnels runoff from the entire Delta watershed to the sea. It is also the only path for ocean tides surging through the Bay into the Delta. Fish, seals, sea lions, and even an occasional whale crisscross from salty seas to fresh rivers and sloughs. Ships from the Pacific navigate the Strait to inland ports like Pittsburg, Stockton, and Sacramento.

From an ancient flood-worn hillside, to the nautical thoroughfare of today, Carquinez Strait is one of the many spokes of water linking California through the hub of the Delta.

Erected by East Bay Regional Parks District.

Topics. This historical marker is listed in these topic lists: Environment • Waterways & Vessels.

Location. 38° 0.699′ N, 121° 43.715′ W. Marker is in Oakley, California, in Contra Costa County. Marker can be reached from Big Break Road. Touch for map. Marker is in this post office area: Oakley CA 94561, United States of America. Touch for directions.

Other nearby markers.

Paid Advertisement

Click on the ad for more information.
Please report objectionable advertising to the Editor.

Click or scan to see
this page online

At least 8 other markers are within 5 miles of this marker, measured as the crow flies. The Migrating Delta (here, next to this marker); California's Big Water Projects: How Did We Get Here? (a few steps from this marker); The San Joaquin: A River Runs Dry (within shouting distance of this marker); Dredges (about 700 feet away, measured in a direct line); Stopped by Impenetrable Marshes (approx. 0.2 miles away); "...What we see and have before us is not a river, but much water in a pond" (approx. 1.3 miles away); Anza Expedition Campsite 101 (approx. 1.3 miles away); July 4, Anno Domini, 1951 (approx. 4.2 miles away). Touch for a list and map of all markers in Oakley.

More about this marker. The marker is located in Big Break Regional Park, in the Delta Discovery Experience area by the river, by the picnic tables.

Also see . . . Carquinez Strait (Wikipedia).

The Carquinez Strait is a narrow tidal strait in Northern California. It is part of the tidal estuary of the Sacramento and the San Joaquin rivers as they drain into the San Francisco Bay. The strait is eight miles (13 km) long and connects Suisun Bay, which receives the waters of the combined rivers, with San Pablo Bay, a northern extension of the San Francisco Bay.

(Submitted on January 18, 2022.)

Carquinez Strait Marker - wide view image. Click for full size.

Photographed By Andrew Ruppenstein, January 13, 2022

2. Carquinez Strait Marker - wide view

Marker inset: the Carquinez Strait over time image. Click for full size.

images courtesy of Google Earth

3. Marker inset: the Carquinez Strait over time

Captions: The Central Valley, filled by Corcoran Lake 760,000 years ago, drained to the ocean through Monterey Bay. (left); Today our coast and interior are connected by Carquinez Strait. (right)

Credits. This page was last revised on January 18, 2022. It was originally submitted on January 18, 2022, by Andrew Ruppenstein of Lamorinda, California. This page has been viewed 446 times since then and 117 times this year. Photos: 1, 2, 3. submitted on January 18, 2022, by Andrew Ruppenstein of Lamorinda, California.