[citation needed] The United States Government has designated 13,000 acres (53 km2) in the Napa Sonoma Marsh as the San Pablo Bay National Wildlife Refuge.

[citation needed] The marsh is fed by Sonoma Creek (which drains the Sonoma Valley), Tolay Creek (originating in the Tolay Lake basin), and the Napa River (which drains the Napa Valley).

[4] Around 1860, the Napa Sonoma Marsh was one of the most productive wetlands of the Pacific Coast, providing habitat for millions of birds.

[6] During the Vietnam War, the Navy utilized the marsh as a training ground for crews of the Navy's new Swift boats and patrol boats, operating out of Mare Island Naval Shipyard at the marsh's southern terminus.

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