A logical step in the company's program for finding and developing supplies of natural gas was its entry into the oil business. This move was marked by major discoveries at Augusta, Kansas, in 1914, and in El Dorado a year later. In 1928, a Cities Service subsidiary, Indian Territory Illuminating Oil Company, discovered the Oklahoma City field, one of the world's largest. Another participated in the discovery of the East Texas field, which, in its time, was the most sensational on the globe.