Tranche Update on U.S. Silica Holdings, Inc.'s Equity Buyback Plan announced on May 14, 2018.

U.S. Silica Holdings, Inc. is a global performance materials company. The Company is a producer of commercial silica used in the oil and gas industry and in a range of industrial applications. Its segments include Oil & Gas Proppants, and Industrial & Specialty Products. The Oil & Gas Proppants segment serves the oil and gas recovery market by providing and delivering fracturing sand, which is pumped down oil and natural gas wells to prop open rock fissures and increase the flow rate of oil and natural gas from the wells. The Industrial & Specialty Products segment consists of over 800 product types and materials used in a variety of markets, including building and construction products, fillers and extenders, filtration, glassmaking, absorbents, foundry, and sports and recreation. Its subsidiaries include EP Minerals and SandBox Logistics. EP Minerals is engaged in the production of products derived from diatomaceous earth, perlite, engineered clays and non-activated clays.