Map of offshore sediment thickness in State Waters between Drakes Bay and Salt Point, north of the Russian River.

Map of offshore sediment thickness in State Waters between Drakes Bay and Salt Point, north of the Russian River. The thickest sediment in the region occurs offshore of the Russian River, and in a large bar along the south flank of Point Reyes Head. There is a relative lack of offshore sediment between Bodega Head and Point Reyes, where the shelf is characterized by abundant rocky habitat and much of the coastal sediment is trapped in large onshore dune fields.