On the Record · Mplx
Mplx subsidiaries, as it lists them
The subsidiaries Mplx lists in its latest annual report, with the jurisdiction of each, linked to the filing.
Subsidiaries it lists
| Subsidiary | Jurisdiction |
|---|---|
| Andeavor Field Services LLC | Delaware |
| Andeavor Logistics LLC | Delaware |
| Andeavor Midstream Partners GP LLC | Delaware |
| Andeavor Midstream Partners LP | Delaware |
| Asphalt Terminals LLC | Delaware |
| BANGL Operating, LLC | Delaware |
| BANGL, LLC | Delaware |
| Blanchard Terminal Company LLC | Delaware |
| Canton Refining Logistics LLC | Delaware |
| Catlettsburg Refining Logistics LLC | Delaware |
| Detroit Refining Logistics LLC | Delaware |
| Galveston Bay Refining Logistics LLC | Delaware |
| Garyville Refining Logistics LLC | Delaware |
| Hardin Street Marine LLC (d/b/a MPLX Marine) | Delaware |
| Hardin Street Transportation LLC | Delaware |
| Marathon Pipe Line LLC (d/b/a Marathon Pipe Line (Delaware) LLC) | Delaware |
| MarkWest Agua Blanca Pipeline, L.L.C. | Delaware |
| MarkWest Bluestone Ethane Pipeline, L.L.C. | Delaware |
| MarkWest Energy East Texas Gas Company, L.L.C. | Delaware |
| MarkWest Energy Operating Company, L.L.C. | Delaware |
| MarkWest Energy Partners LLC | Delaware |
| MarkWest Energy West Texas Gas Company, L.L.C. | Delaware |
| MarkWest Hydrocarbon, L.L.C. | Delaware |
| MarkWest Liberty Bluestone, L.L.C. | Delaware |
| MarkWest Liberty Ethane Pipeline, L.L.C. | Delaware |
| MarkWest Liberty Gas Gathering, L.L.C. | Delaware |
| MarkWest Liberty Midstream & Resources, L.L.C. | Delaware |
| MarkWest Liberty NGL Pipeline, L.L.C. | Delaware |
| MarkWest Mariner Pipeline, L.L.C. | Delaware |
| MarkWest Ohio Fractionation Company, L.L.C. | Delaware |
| MarkWest Oklahoma Gas Company, L.L.C. | Oklahoma |
| MarkWest Panola Utility Company, L.L.C. | Delaware |
| MarkWest Pioneer, L.L.C. | Delaware |
| MarkWest Pipeline Company, L.L.C. | Texas |
| MarkWest Ranger Pipeline Company, L.L.C. | Delaware |
| MarkWest Tornado GP, L.L.C. | Delaware |
| MarkWest Utica Operating Company, L.L.C. | Delaware |
| MPL Louisiana Holdings LLC | Delaware |
| MPLX Delaware Basin LLC | Delaware |
| MPLX Fuels Distribution LLC | Delaware |
| MPLX Operations LLC | Delaware |
| MPLX Ozark Pipe Line LLC | Delaware |
| MPLX Terminal and Storage LLC | Delaware |
| MPLX Terminals LLC | Delaware |
| MPLXIF LLC | Delaware |
| Mt. Airy Terminal LLC | Delaware |
| MWE GP LLC | Delaware |
| Northwind Delaware Holdings LLC | Delaware |
| Northwind Management Holdings LLC | Delaware |
| Northwind Management LLC | Delaware |
| Northwind Midstream Operating LLC | Delaware |
| Northwind Midstream Partners LLC | Delaware |
| Northwind Midstream Sub I LLC | Delaware |
| Ohio Condensate Company, L.L.C. | Delaware |
| Ohio River Pipe Line LLC | Delaware |
| Robinson Refining Logistics LLC | Delaware |
| Tesoro Alaska Pipeline Company LLC | Delaware |
| Tesoro Alaska Terminals LLC | Delaware |
| Tesoro Great Plains Gathering & Marketing LLC (d/b/a Patterson Rail Terminal) | Delaware |
| Tesoro High Plains Pipeline Company LLC | Delaware |
| Tesoro Logistics Finance Corp. | Delaware |
| Tesoro Logistics Northwest Pipeline LLC | Delaware |
| Tesoro Logistics Operations LLC | Delaware |
| Tesoro Logistics Pipelines LLC | Delaware |
| Tesoro SoCal Pipeline Company LLC | Delaware |
| Triple Streams Gathering LLC | Delaware |
| West Relay Gathering Company, L.L.C. | Delaware |
| Western Refining Conan Gathering, LLC | Delaware |
| Western Refining Delaware Basin Storage, LLC | Delaware |
| Western Refining Pipeline, LLC | New Mexico |
| Western Refining Terminals, LLC | Delaware |
| WNRL Energy GP, LLC | Delaware |
| WNRL Energy, LLC | Delaware |
| Woodhaven Cavern LLC | Delaware |
From Exhibit 21 of the 10-K for 2025. Companies must list their significant subsidiaries there and may leave out smaller ones, so this is the company’s own list, not every entity it owns.
Read from Mplx’s annual reports (10-K for 2025, 10-K for 2024, 10-K for 2023) and the financial data it files with the SEC, as of 2026-02-26. Every quotation is word for word from the filing linked beside it; how these pages are built and checked. The full record is in its company data sheet.