San Francisco Bay

San Francisco Bay is a vast tidal estuary where California’s inland rivers meet the Pacific through the Golden Gate, forming the geographic and economic core of the Bay Area. Shaped by fault movement and flooded after the last ice age, it later became home to Ohlone peoples and, after European arrival in 1769 and 1775, one of the great harbors of the American West, especially during the Gold Rush. Mining sediment and extensive filling drastically reduced its wetlands and altered its shoreline, but late-20th-century conservation efforts began to restore some losses. Today it remains both a major working harbor and one of California’s most important ecological landscapes.