X0306 4 2018-11-05 0 0001524741 U.S. SILICA HOLDINGS, INC. SLCA 0001529402 Casper Bradford B C/O U.S. SILICA HOLDINGS, INC. 8490 PROGRESS DRIVE, SUITE 300 KATY TX 21701 0 1 0 0 EVP & Chief Commercial Officer Common Stock 2018-11-05 4 M 0 12048 A 30600 D Common Stock 2018-11-05 4 F 0 5343 14.38 D 25257 D Common Stock 2019-02-12 4 A 0 45314 0.00 A 70571 D Common Stock 2019-02-12 4 A 0 22637 12.91 A 93208 D Common Stock 2019-02-12 4 F 0 10325 12.91 D 82883 D Restricted Stock Units 2018-11-05 4 M 0 12048 0.00 D Common Stock 12048 0 D Scheduled vesting of restricted stock units granted on November 5, 2015. Represents tax withholding on vested restricted stock units. Represents restricted stock granted on February 12, 2019 which will vest in three equal installments on the anniversaries of the grant date. On March 31, 2016, the reporting person was granted performance-based restricted stock units subject to vesting based on the attainment of pre-established objective financial goals, business unit performance objectives and individual personal performance objectives. Certain performance criteria for 2018 were met, resulting in vesting of the grant as to 22,637 shares of the issuer's common stock on February 12, 2019. Represents tax withholding on vested performance-based stock. Each restricted stock unit represents a contingent right to receive one share of common stock upon vesting of the unit. Restricted Stock Units granted on November 5, 2015 and vesting in three equal installments on the anniversaries of the grant date. /s/ Robert M. Hayward, P.C. by Power of Attorney 2019-02-14