Tesoro Corporation (Tesoro) is an independent petroleum refiners and marketers in the United States. The Company�s subsidiaries, operating through two business segments: manufacture and sell transportation fuels. Its refining operating segment (refining), which operates seven refineries in the western United States, refines crude oil and other feedstocks into transportation fuels, such as gasoline, gasoline blendstocks, jet fuel and diesel fuel, as well as other products, including heavy fuel oils, liquefied petroleum gas, petroleum coke and asphalt. This operating segment sells refined products in wholesale and bulk markets to a range of customers within the operations area. Its retail operating segment (retail) sells transportation fuels and convenience products in 18 states through a network of 1,175 retail stations, under the Tesoro, Shell and USA Gasoline brands.