California currently has between 11 and 17 oil refineries in operation, depending on the source and the definition of operational status.

• According to the World Resources Institute, about 11 refineries operate today in California, concentrated mainly in Los Angeles County, Contra Costa County, and Kern County in the San Joaquin Valley

• The California Air Resources Board lists 15 refineries that produce transportation fuel, plus 4 additional refineries that do not produce transportation fuel, totaling 19 refineries, though not all may be fully operational or producing the same outputs

• The Western States Petroleum Association states California has 17 refineries with a combined capacity of nearly two million barrels per calendar day, located in the Central Valley, Los Angeles County, and the San Francisco Bay Area

• Recent news reports indicate closures of some refineries, such as Valero's Benicia refinery and Phillips 66's Los Angeles refinery, which would reduce the number to about 7 full refineries and 5 smaller privately owned ones in the near future

In summary, the most consistent figure for currently operating refineries is around 15 to 17, but this number is declining due to recent and planned closures. Historically, California had about 40 to 50 refineries several decades ago