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UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington , D.C. 20549 FORM 10 - K ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31 , 2020 OR TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 ( d ) OF SECURITIES EXCHANGE ACT OF 1934 For the transition period from Commission file number 001-37362 Delaware ( State or Other Jurisdiction of Incorporation or Organization ) 1001 Fannin Street , Suite 2020 Houston , Texas ( Address of Principal Executive Offices ) to Black Stone Minerals , L.P. ( Exact Name of Registrant As Specified in its charter ) 13 ) 445-3200 ( Registrant's telephone number , including area code ) Large Accelerated Filer Non - Accelerated Filer Securities registered pursuant to Section 12 ( b ) of the Act : Trading Symbol ( s ) BSM X 47-1846692 ( I.R.S. Employer Identification No. ) 77002 ( Zip Code ) Title of each class Common Units Representing Limited Partner Interests Indicate by check mark if the registrant is a well - known seasoned issuer , as defined in Rule 405 of the Securities Act . Yes x No Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15 ( d ) of the Act . Yes No x Indicate by check mark whether the registrant ( 1 ) has filed all reports required to be filed by Section 13 or 15 ( d ) of the Securities Exchange Act of 1934 during the preceding 12 months ( or for such shorter period that the registrant was required to file such reports ) , and ( 2 ) has been subject to such filing requirements for the past 90 days . Yes x No Name of each exchange on which registered New York Stock Exchange Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S - T ( § 232.405 of this chapter ) during the preceding 12 months ( or for such shorter period that the registrant was required to submit such files ) . Yes x No " Indicate by check mark whether the registrant is a large accelerated filer , an accelerated filer , a non - accelerated filer , a smaller reporting company , or an emerging growth company . See the definitions of " large accelerated filer , " " accelerated filer , " " smaller reporting company , " and " emerging growth company " in Rule 12b - 2 of the Exchange Act . Accelerated Filer Smaller Reporting Company Emerging Growth Company If an emerging growth company , indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13 ( a ) of the Exchange Act . □ Indicate by check mark whether the registrant has filed a report on and attestation to its management's assessment of the effectiveness of its internal control over financial reporting under Section 404 ( b ) of the Sarbanes - Oxley Act ( 15 U.S.C. 7262 ( b ) ) by the registered public accounting firm that prepared or issued its audit report . 0 0 Indicate by check mark whether the registrant is a shell company ( as defined in Rule 12b - 2 of the Exchange Act ) . Yes □ No x The aggregate market value of the common units held by non - affiliates was $ 1,015,788,702 on June 30 , 2020 , the last business day of the registrant's most recently completed second fiscal quarter , based on a closing price of $ 6.50 per unit as reported by the New York Stock Exchange on such date . As of February 19 , 2021 , 207,266,383 common units and 14,711,219 Series B cumulative convertible preferred units of the registrant were outstanding . Documents Incorporated by Reference : Certain information called for in Items 10 , 11 , 12 , 13 , and 14 of Part III are incorporated by reference from the registrant's definitive proxy statement for the annual meeting of unitholders .