MPLX LP is a master limited partnership (MLP) formed by Marathon Petroleum Corporation (MPC) to own, operate, develop and acquire midstream energy infrastructure assets. The Company is engaged in the gathering, processing and transportation of natural gas; the gathering, transportation, fractionation, storage and marketing of natural gas liquids (NGLs), and the gathering, transportation and storage of crude oil and refined petroleum products. Its segments are Logistics and Storage (L&S), and Gathering and Processing (G&P). The L&S segment includes transportation and storage of crude oil, refined products and other hydrocarbon-based products. As of December 31, 2017, the G&P segment operated various natural gas gathering systems that had a combined 5,439 million cubic feet per day (mmcf/d) throughput capacity. As of December 31, 2017, its assets included infrastructure to support MPC, including approximately 2,194 miles of crude oil and refined product pipelines across 17 states.