Los Osos Back Bay is a prehistoric Chumash archaeological site in the Los Osos e coastal area in San Luis Obispo County, California

San Luis Obispo County, California

San Luis Obispo County is a county located along the Pacific Ocean in the Central Coast of the U.S. state of California, between Los Angeles and the San Francisco Bay Area. As of the 2010 census its population was 269,637, up from 246,681 at the 2000 census...

, USA. These Native Americans

Native Americans in the United States

Native Americans in the United States are the indigenous peoples in North America within the boundaries of the present-day continental United States, parts of Alaska, and the island state of Hawaii. They are composed of numerous, distinct tribes, states, and ethnic groups, many of which survive as...

 had a significant settlement named Los Osos Back Bay on a stabilized sand dune somewhat to the west of the Elfin Forest

Elfin Forest, San Luis Obispo County

The Los Osos Elfin Forest in San Luis Obispo County area consists of stabilized sand dunes abutting a portion of the Morro Bay Estuary. Naturally a harsh location for plants to grow, the California native Coast Live Oak found a special niche among the once shifting sand dunes...

; in fact, there is another extant midden

Midden

A midden, is an old dump for domestic waste which may consist of animal bone, human excrement, botanical material, vermin, shells, sherds, lithics , and other artifacts and ecofacts associated with past human occupation...

within the Elfin Forest itself.

Los Osos Back Bay is also the name for the southernmost part of the Morro Bay estuary (known by the locals as "the back bay"), where the native Chumash at the eponymous archaeological site gathered marine resources, as coastal tribes along this part of the California coast regularly did.