Exhibit 10.4

BLACK STONE MINERALS COMPANY, L.P.

FIRST AMENDMENT TO 2009 EMPLOYMENT AGREEMENT

This First Amendment (the “First Amendment”) to the 2009 Employment Agreement between Black Stone Minerals Company, L.P. (“BSMC”) and Thomas L. Carter, Jr. (“Employee”) effective as of April 1, 2009 (the “Agreement”) is made and entered into effective as of June 25, 2014.

RECITALS

a. Conform the definition of “Target Bonus” to the definition used for other senior executives of BSMC; and

b. Update the definition of “cause.”

AGREEMENT

In consideration of the mutual covenants set forth herein, and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, BSMC and Employee, intending to be bound, hereby agree as follows:

1. Definitions. Capitalized terms used but not defined in this First Amendment (including in the recitals) have the meanings set forth in the Agreement.

2. Amendments to the Agreement.

2.1. Section 1(d)(ii) of the Agreement is amended and restated as follows:

“(ii) Not later than March 30 of each year during the Employment Term, BSMC shall pay Employee an annual performance bonus with respect to the previous calendar year, equal to the product of Employee’s Target Bonus and EBITDAX Achievement Percentage, defined as follows:

Employee shall not be entitled to receive an annual performance bonus unless Employee is employed by BSMC on the earlier of the date of payment of the annual performance bonus or the due date thereof, except to the extent otherwise provided in Section 2(d)(i) or 2(d)(ii).”

2.2. Section 2(a) of the Agreement is amended as follows:

2.2.1. The word “or” is appended to the end of subsection (iv).

2.2.2. At the end of subsection (v), “;or” is deleted and replaced with a period.

2.2.3. Subsection (vi) is deleted in its entirety.

2.3 Appendix A to this First Amendment is appended as Appendix A to the Agreement:

3. Agreement. Except as expressly amended by this First Amendment, the Agreement shall continue in full force and effect and is hereby ratified and affirmed by BSMC and Employee.

4. General Provisions. This First Amendment may be executed in duplicate counterparts and each such counterpart shall be deemed an original agreement for all purposes. All signatures hereto may be transmitted by facsimile or scanned email, and such facsimile or scanned email will, for all purposes, be deemed to be the original signature of the party whose signature it reproduces, and will be binding upon such party. This First Amendment is governed by and shall be construed in accordance with the law of the State of Texas, without regard to its conflicts-of-law principles.

(signature page follows)

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IN WITNESS WHEREOF, this First Amendment is entered into as of the date first set forth above.

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APPENDIX A

DETERMINATION OF EBITDAX ACHIEVEMENT PERCENTAGE

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