X0306 4 2022-02-10 0001524741 U.S. SILICA HOLDINGS, INC. SLCA 0001350906 Merril Donald A C/O US SILICA HOLDINGS INC. 24275 KATY FREEWAY, SUITE 600 KATY TX 77494 0 1 0 0 EVP & Chief Financial Officer Common Stock 2022-02-10 4 A 0 46644 0 A 251061 D Common Stock 2022-02-12 4 A 0 35193 0 A 286254 D Common Stock 2022-02-12 4 F 0 10178 10.13 D 276076 D Represents restricted stock units granted on February 10, 2022 which will vest in three equal installments on the anniversary of the grant date. Includes (i) 26,882 restricted stock units granted on February 6, 2020 which will vest on February 6, 2023; (ii) 34,091 restricted stock units granted on February 12, 2021 which will vest in equal installments on February 12, 2023 and 2024 and (iii) 46,644 restricted stock units granted on February 10, 2022 which will vest in three equal installments on the anniversary of the grant date. On February 12, 2019, the reporting person was granted performance-based restricted stock units subject to vesting based on the attainment of certain pre-established objectives. Certain performance criteria were met, resulting in vesting of the grant as to 35,193 shares of the issuer's common stock on February 12, 2022. Represents tax withholding on vested performance-based restricted stock units. /s/ Stacy Russell, as Attorney-in-Fact 2022-02-14