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".