MPLX is a diversified, growth-oriented master limited partnership formed in 2012 by Marathon Petroleum Corporation (MPC) to own, operate, develop and acquire midstream energy infrastructure assets. MPLX is engaged in the gathering, processing and transportation of natural gas; the gathering, transportation, fractionation, storage and marketing of NGLs; and the transportation, storage and distribution of crude oil and refined petroleum products through a marine fleet and approximately 10,000 miles of crude oil and light product pipelines.

Headquartered in Findlay, Ohio, MPLX's assets consist of a network of crude oil and products pipelines and supporting assets, including storage facilities (tank farms) located in the Midwest and Gulf Coast regions of the United States; 62 light-product terminals with approximately 24 million barrels of storage capacity; an inland marine business; storage caverns with approximately 2.8 million barrels of storage capacity; a barge dock facility with approximately 78,000 barrels per day of crude oil and product throughput capacity; and gathering and processing assets that include approximately 5.9 billion cubic feet per day of gathering capacity, 8.7 billion cubic feet per day of natural gas processing capacity and 610,000 barrels per day of fractionation capacity. In addition, MPLX provides fuels distribution services to MPC and owns refining logistics assets consisting of tanks with storage capacity of approximately 56 million barrels as well as refinery docks, loading racks and associated piping.