MPLX LP

Row 1 · Balance 1

F1: On July 30, 2019 (the "Effective Time"), pursuant to the Agreement and Plan of Merger, dated as of May 7, 2019, by and among the Issuer, MPLX LP ("MPLX"), Tesoro Logistics GP, LLC ("TLGP"), MPLX GP LLC (the "General Partner") and MPLX MAX LLC ("Merger Sub"), Merger Sub merged with and into the Issuer (the "Merger"), with the Issuer surviving the Merger as a wholly owned subsidiary of MPLX.

F2: At the Effective Time, each common unit representing a limited partner interest in the Issuer was converted into the right to receive common units representing limited partner interests in MPLX at exchange ratios as set forth in the Merger Agreement. At the Effective Time, a limited partner interest in the Issuer which constitutes in the aggregate 100% of the aggregate partnership interest (as defined in Delaware Revised Uniform Limited Partnership Act, as amended) of all limited partners in the Issuer was issued to MPLX. Marathon Petroleum Corporation ("MPC") and certain of the other Reporting Persons may be deemed to beneficially own the limited partner interest of the Issuer owned by MPLX, but each disclaims beneficial ownership of such security except to the extent of each Reporting Person's pecuniary interest therein.

F3: This Form 3 is filed jointly by Tesoro Alaska Company LLC ("TAC") and TLGP with respect to the events described herein by a Reporting Group consisting of MPC, MPC Investment LLC ("MPCI"), the General Partner, MPLX, MPLX Logistics Holdings LLC ("Logistics Holdings"), Andeavor LLC, Western Refining, Inc. ("WRI"), Giant Industries, Inc. ("GII"), Western Refining Southwest, Inc. ("WRSI"), Tesoro Refining & Marketing Company LLC ("TRMC"), TAC and TLGP. As described below, TAC and TLGP are filing this separate Form 3 related to the same events as a Form 3 filed by the other members of the Reporting Group.

F4: Following the Merger, MPCI, the General Partner, Logistics Holdings, WRSI and TLGP beneficially own approximately 63% of the common units representing limited partner interests in MPLX, and the General Partner owns the non-economic general partner interest in MPLX. MPCI, a direct wholly owned subsidiary of MPC, owns all of the membership interests in both the General Partner and Logistics Holdings. The General Partner is the general partner of MPLX. Andeavor LLC is a wholly owned subsidiary of MPC. WRI is a wholly owned subsidiary of Andeavor LLC. GII is a wholly owned subsidiary of WRI. WRSI is a wholly owned subsidiary of GII. TRMC and TAC are wholly owned subsidiaries of WRSI. WRSI, TAC and TRMC collectively own all of the membership interests in TLGP. Accordingly, MPCI, the General Partner, Logistics Holdings, Andeavor LLC, WRI, GII, WRSI, TRMC, TAC and TLGP are all direct or indirect wholly owned subsidiaries of MPC.