Oso Flaco Creek drains a watershed within the greater 9,605 acres (4 ha) Santa Maria River Watershed. The creek forms Oso Flaco Lake, now part of the Oso Flaco Lake Natural Area in the Guadalupe-Nipomo Dunes located north of the city of Guadalupe, California. A boardwalk follows the creek, then across Oso Flaco Lake, and leads to the ocean.
The Chumash Native Americans were inhabitants of the Guadalupe-Nipomo Dunes first seen by early Spanish maritime explorers. Europeans did not travel through the dunes until September 1769 when members of Don Gaspar de Portolà’s overland expedition camped here. The name Oso Flaco means “skinny bear” and the origin of the name comes from a story about a bear shot by the Portolà Expedition along the shores of the lake. After eating the bear, two of the explorers became sick, and it was later learned that the Chumash poisoned dangerous wildlife by feeding them tainted meat.
The Guadalupe-Nipomo Dunes is the largest remaining natural dune system south of San Francisco and the second-largest in California. It encompasses an 18-mile (29 km) stretch of coastline and is home to a unique ecosystem that includes many endangered and threatened plants and animals. To protect the dunes environment, much of the area has been set aside for conservation and has been recognized as a National Natural Landmark. The California Office of Environmental Health Hazard Assessment has issued an advisory for any fish caught in Oso Flaco Lake due to elevated levels of pollutants including DDTs, dieldrin, and mercury. Read more here and here. Explore more of Oso Flaco Creek and the Guadalupe-Nipomo Dunes here: