The East Texas Oil Field is a large oil and gas field in east Texas. Covering and parts of five counties, and having 30,340 historic and active oil wells, it is the second-largest oil field in the United States outside of Alaska, and first in total volume of oil recovered since its discovery in 1930. Over 5.42 billion barrels of oil have been produced from it to-date. It is a component of the Mid-Continent Oil Province, the huge region of petroleum deposits extending from Kansas to New Mexico to the Gulf of Mexico.