CountryMark is an American-owned oil exploration, production, and refining company that provides the Midwestern states with state-of-the-art products and over 100 CountryMark-branded fuel stations. The company is located in Indianapolis, Indiana and its refinery is in Mount Vernon, Indiana. On a daily basis, its refinery processes an average of around 27,000 barrels of crude oil. It is the largest buyer of oil produced from the Illinois Basin, the region of land that covers the southern regions of Illinois and Indiana as well as parts of Western Kentucky. In 2016, CountryMark purchased $300,000,000 worth of Illinois Basin crude oil.