| | | | | |
Name
| Jurisdiction of Formation |
| Hourglass Acquisition I, LLC | Delaware |
| Preferred Rocks USS Inc. | Delaware |
| Hourglass Holdings, LLC | Delaware |
| USS Holdings, Inc. | Delaware |
| U.S. Silica Company | Delaware |
| Pennsylvania Glass Sand Corporation | Delaware |
| The Fulton Land and Timber Company | Pennsylvania |
| Ottawa Silica Company | Delaware |
| Ottawa Silica Company, Ltd. | Quebec, Canada |
| Coated Sand Solutions, LLC | Delaware |
| Cadre Services Inc. | Delaware |
| Cadre Material Products, LLC | Texas |
| Fairchild Silica, LLC | Delaware |
| Utica Silica, LLC | Delaware |
| Tyler Silica Company | Delaware |
| New Birmingham Resources, LLC | Texas |
| NBR Sand, LLC | Texas |
| NBR Maritime I, LLC | Texas |
| NBR Maritime II, LLC | Texas |
| Sandbox Enterprises, LLC | Texas |
| Oren Technologies, LLC | Texas |
| Sandbox Leasing, LLC | Texas |
| Sandbox Logistics, LLC | Texas |
| Sandbox Transportation, LLC | Texas |
| Mississippi Sand, LLC | Missouri |
| Arcadia Sand, LLC | Delaware |
| Boss Energy Resources, LLC | Delaware |
| Seagraves Development, LLC | Delaware |
| EP Minerals Holdings, Inc. | Delaware |
| EP Acquisition, LLC | Delaware |
| EP Management Corporation | Delaware |
| EP Minerals, LLC | Delaware |
| 2473428 Ontario, Inc. | Ontario, Canada |
| EP Engineered Clays Corporation | Delaware |
| EP Minerals International S.A.S. | France |
| EP Minerals Europe Verwaltungs und Beteiligungs GmbH | Germany |
| EP Minerals Europe GmbH & Co. KG | Germany |
| EP Mexican Parent, Inc. | Delaware |
| EP Minerals de Mexico S. de R.L. de C.V. | Mexico |
| Celatom de Mexico S. de R.L. de C.V. | Mexico |
| Kermit Pipeline, LLC (50% ownership) | Texas |
| Spruce Acquisition, LLC | Delaware |
