Marathon Oil in North America, including $600 million in the Eagle Ford and $200 million in the Bakken formation. The company owns 277,000 net acres in the Bakken formation. Marathon began as The Ohio Oil Company in 1887. In 1889, it was purchased by John D. Rockefeller's Standard Oil. It remained a part of Standard Oil until Standard Oil was broken in 1911. In 1930, The Ohio Oil Company bought the Transcontinental Oil Company and established the "Marathon" brand name. In 1962, the company changed its name to "Marathon Oil Company". In 1982, Mobil made a hostile offer to buy the company;
Rio Blanco Oil Shale Company $132 million. Later the company acquired the modified in-situ technology developed by Occidental Petroleum. The major differences of two technologies lay in methods of rubblizing and fractioning of the shale deposit. The company also obtained a license for using the Lurgi-Ruhrgas process. In 1985, Amoco (former Standard Oil of Indiana) took control over the company acquiring Gulf Oil's take from the Chevron Corporation. In the same year, the company ceased its operations. Rio Blanco Oil Shale Company The Rio Blanco Oil Shale Company was an American shale oil extraction technology research and development company. The company was established as a