In 1915, the El Dorado Oil Field was the first oil field that was found using science/geologic mapping. It was around the city of El Dorado. It was part of the Mid-Continent oil province. By 1918, the El Dorado Oil Field was the largest single field producer in the United States. It was responsible for 12.8% of national oil production and 9% of the world production. Some said it was as "the oil field that won World War I".