Marathon Petroleum Corporation is engaged in refining, marketing, retail and transportation businesses in the United States and the largest east of the Mississippi. The Company operates through three segments: Refining & Marketing; Speedway; and Midstream. The Refining & Marketing segment refines crude oil and other feedstocks at the Company's seven refineries in the Gulf Coast and Midwest regions of the United States. Its Speedway segment sells transportation fuels and convenience products in the retail market in the Midwest, East Coast and Southeast regions of the United States. The Company's Midstream is engaged in the operations of MPLX LP and certain other related operations. It gathers, processes and transports natural gas, natural gas liquids (NGLs), crude oil and refined products. MPLX is a limited partnership which owns, operates, develops and acquires midstream energy infrastructure assets.