Forty-five years before the drilling of the famous 1859 Colonel Drake oil well in Pennsylvania, oil was produced and marketed from salt brine wells dug in southeast Ohio. The oil was bottled and sold as a cure-all medicine, Seneca Oil. In 1860, one of the first oil fields in Ohio was discovered approximately 10 miles southeast of these wells. The 1885 discovery of the giant Lima-Indiana oil field set off the oil boom of northwest Ohio, a period of land speculation and rapid oil field development that lasted over 20 years and propelled Ohio into the leading oil-producing state from 1895 to 1903. John D. Rockefeller's Standard Oil of Cleveland built storage tanks, pipelines, and a refinery near Lima. The Ohio Oil Company, now Marathon Oil, was active in the area and still maintains an office in Findlay. The Bremen oil field was discovered in south-central Ohio in 1907, setting off another oil boom, which included drilling within the city limits.