The leading oil-producing area in the United States in 2014 was Texas (3.17 million barrels (504,000 m3) per day), followed by the federal zone of the Gulf of Mexico (1.40 million barrels (223,000 m3) per day), followed by North Dakota (1.09 million barrels (173,000 m3) per day) and California (0.50 million barrels ( ...read more >>