X0306 4 2018-03-06 0 0001621434 Black Stone Minerals, L.P. BSM 0001639921 Stuart Alexander D. 1001 FANNIN STREET, SUITE 2020 HOUSTON TX 77002 1 0 0 0 Common units representing limited partner interests 2018-03-06 4 P 0 15000 17.4329 A 335234 D Common units representing limited partner interests 2072350 I By North Star Oil & Gas Common units representing limited partner interests 914682 I By Topsfield Energy Ltd. Common units representing limited partner interests 541885 I By RDS Investments, L.P. Common units representing limited partner interests 78265 I By R D Stuart Jr 1996 Trust Common units representing limited partner interests 6687 I By Barbara E Stuart GST Exempt Trust fbo Alexander D Stuart The price reported in Column 4 is a weighted average price. These common units were purchased in multiple transactions at prices ranging from $17.36 to $17.50, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of common units purchased at each separate price within the ranges set forth in this footnote. /s/ Steve Putman, Attorney-in-Fact for Alexander D. Stuart 2018-03-06