Monterey Bay National Marine Sanctuary. Monterey Bay National Marine Sanctuary (MBNMS) is a federal, marine protected area that spans from Rocky Point (Marin County, just north of the Golden Gate Bridge) to Cambria (San Luis Obispo County), California, USA; and includes Elkhorn Slough and the Davidson Seamount Management Zone. Points of interest (bold black font) and cities of interest (light gray font) are notated. Credit: Sophie De Beukelaer (Lynker Technologies LLC/MBNMS).