The Rio Vista Gas Field is a large natural gas field in the Sacramento–San Joaquin River Delta in northern California, adjacent to Rio Vista, California. Discovered in 1936, and in continuous operation since, it has produced over 3.6 trillion cubic feet (100 km³) of gas in its lifetime, and retains an estimated reserve of approximately 330 billion cubic feet (9.3×10⁹ m³). In 2008 alone, the most recent year for which data was available, it produced 18 billion cubic feet (510,000,000 m³) of gas.