Many European mariners sailed over Cordell Bank without even knowing it was there. (Photo: CBNMS)

Coastal California has a rich history of native Americans and early settlers utilizing the marine environment. For millions of years, Cordell Bank was an unknown mystery hidden beneath the waves. Nearshore food resources were so plentiful that there was no reason for the native Miwok Indians to venture miles offshore.

In the late 1800s there was a strong incentive to survey the coast of California to promote safer maritime commerce. Cordell Bank was discovered in 1853 by George Davidson of the U.S. Coast Survey while returning from a mapping expedition on California's north coast.

An extensive study of Cordell Bank began in 1977 with Cordell Expeditions, a non-profit association (Photo: Cordell Expeditions)

Edward Cordell, an accomplished surveyor, conducted additional surveys in 1869 when he was sent to relocate a "shoal west of Point Reyes." Cordell was attracted to the location by the numerous birds and marine mammals. To measure the depth, Cordell lowered a lead weight over the edge until it hit bottom and then measured the line on its return to the surface. Always considered a productive fishing area, not much was known about what life existed on the bank until 1977.

Cordell Bank was first explored underwater in 1977 by a non-profit research association, Cordell Expeditions. Over the next 10 years, divers documented the organisms living on and above the bank. Through these efforts, images of the biological diversity of Cordell Bank were available to the public for the first time. This effort was instrumental in creating Cordell Bank National Marine Sanctuary.