# Relationship history for MSHA mine 2800510

Current hierarchy: **USS Holdings Inc → U.S. Silica Company, LLC → Port Elizabeth Plant**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Energy & Minerals Inc → Port Elizabeth Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** S C R-Sibelco Nv et al → Port Elizabeth Plant; 1950-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** George F Pettinos Inc → Port Elizabeth Plant; 1950-01-01 to 1988-09-20; source msha-controller-operator-history
- **controller_controls_mine:** Lewis  Pettinos → Port Elizabeth Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lewis  Pettinos → George F Pettinos Inc; 1950-01-01 to 1988-09-20; source msha-controller-operator-history
- **operator_operates_mine:** Morie Company Inc → Port Elizabeth Plant; 1988-09-21 to 1996-12-02; source msha-controller-operator-history
- **controller_controls_operator:** Energy & Minerals Inc → Morie Company Inc; 1988-09-21 to 1996-12-02; source msha-controller-operator-history
- **controller_controls_mine:** USS Holdings Inc → Port Elizabeth Plant; 1996-03-09 to 2003-07-18; source msha-controller-operator-history
- **controller_controls_mine:** USS Holdings Inc → Port Elizabeth Plant; 1996-03-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Unimin Corp → Port Elizabeth Plant; 1996-12-03 to 1999-04-30; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Unimin Corp; 1996-12-03 to 1999-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Better Materials Corp → Port Elizabeth Plant; 1999-05-01 to 2005-05-02; source msha-controller-operator-history
- **controller_controls_operator:** USS Holdings Inc → Better Materials Corp; 1999-05-01 to 2003-07-18; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Port Elizabeth Plant; 2003-07-19 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Better Materials Corp; 2003-07-19 to 2005-05-02; source msha-controller-operator-history
- **operator_operates_mine:** U.S. Silica Company, LLC → Port Elizabeth Plant; 2005-05-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USS Holdings Inc → U.S. Silica Company, LLC; 2005-05-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Port Elizabeth Plant; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Better Materials Corp; 2007-08-23 to 2005-05-02; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Port Elizabeth Plant; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Unimin Corp; 2021-01-01 to 1999-04-30; source msha-controller-operator-history