San Luis Obispo County was created on February 18, 1850 and is one of 58 counties in the State of California. The County covers a total of 2,124,248 acres of land, with a population of approximately 271,969 residents.

The Third District includes 61% of the City of San Luis Obispo, the communities of Edna Valley and Avila, the City of Pismo Beach and the City of Grover Beach.