Exhibit 24.1

POWER OF ATTORNEY

KNOW ALL BY THESE PRESENTS, that each of the undersigned directors and officers of MPLX GP LLC, a Delaware limited liability company and general partner of MPLX LP, a Delaware limited partnership (the “Registrant”), does hereby constitute and appoint Gary R. Heminger, Timothy T. Griffith and Ian D. Feldman, or any of them, each acting alone, as the true and lawful attorney-in-fact or attorneys-in-fact for each of the undersigned, with full power of substitution and resubstitution, and in the name, place and stead of each of the undersigned, to execute and file, with the Securities and Exchange Commission under the Securities Act of 1933 (the “Securities Act”) (i) one or more Registration Statements on Form S-4 (the “Form S-4 Registration Statement”) relating to the registration of the common units representing limited partnership interests of the Registrant, and such other securities, if any, that are registered pursuant to the Form S-4 Registration Statement (or any amendments, restatements or supplements thereto after the date hereof), (ii) any and all amendments, supplements and exhibits thereto, including pre-effective and post-effective amendments or supplements and Registration Statements filed pursuant to Rule 462(b) of the Securities Act and (iii) any and all applications or other documents to be filed with the Securities and Exchange Commission or any state securities commission or other regulatory authority or exchange with respect to the securities covered by the Form S-4 Registration Statement, with full power and authority to do and perform any and all acts and things whatsoever required, necessary or desirable to be done in the premises, or in the name, place and stead of the said director or officer, hereby ratifying and approving the acts of said attorneys and any of them and any such substitute. This Power of Attorney may be executed in multiple counterparts, each of which will be deemed an original with respect to the person executing it.

IN WITNESS WHEREOF, the undersigned have hereunto set their hands as of this 31st day of July 2015.

Signature		Title
/s/ Gary R. Heminger Gary R. Heminger		Chairman of the Board of Directors and Chief Executive Officer of MPLX GP LLC (Principal Executive Officer)
/s/ Timothy T. Griffith Timothy T. Griffith		Director, Vice President and Chief Financial Officer of MPLX GP LLC (Principal Financial Officer)
/s/ Ian D. Feldman Ian D. Feldman		Controller of MPLX GP LLC (Principal Accounting Officer)
/s/ Pamela K.M. Beall Pamela K.M. Beall		Director and President of MPLX GP LLC
/s/ David A. Daberko David A. Daberko		Director of MPLX GP LLC
/s/ Christopher A. Helms Christopher A. Helms		Director of MPLX GP LLC
/s/ Garry L. Peiffer Garry L. Peiffer		Director of MPLX GP LLC
/s/ Dan D. Sandman Dan D. Sandman		Director of MPLX GP LLC
/s/ John P. Surma John P. Surma		Director of MPLX GP LLC
/s/ Donald C. Templin Donald C. Templin		Director and Executive Vice President of MPLX GP LLC
/s/ C. Richard Wilson C. Richard Wilson		Director of MPLX GP LLC