Marathon Petroleum Corporation is a downstream energy company. The Company is engaged in the petroleum product refining, marketing, retail and midstream business in the United States. The Company operates through two segments: Refining & Marketing 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 Midstream segment is engaged in the operations of MPLX LP and other related operations. Midstream transports, stores, distributes and markets crude oil and refined products principally for the Refining & Marketing segment through refining logistics assets, pipelines, terminals, towboats and barges; gathers, processes and transports natural gas; and gathers, transports, fractionates, stores and markets Natural gas liquids (NGLs).