# Relationship history for MSHA mine 0900149

Current hierarchy: **Covia Holdings LLC → Covia Clay LLC → Hephzibah 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:** S C R-Sibelco Nv et al → Hephzibah Plant; 1950-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Babcock & Wilcox Co-Insulating Products Div → Hephzibah Plant; 1950-01-01 to 1985-01-22; source msha-controller-operator-history
- **controller_controls_mine:** Mc Dermott Inc → Hephzibah Plant; 1950-01-01 to 1985-01-22; source msha-controller-operator-history
- **controller_controls_operator:** Mc Dermott Inc → Babcock & Wilcox Co-Insulating Products Div; 1950-01-01 to 1985-01-22; source msha-controller-operator-history
- **operator_operates_mine:** Albion Kaolin Company → Hephzibah Plant; 1985-01-23 to 2000-06-20; source msha-controller-operator-history
- **controller_controls_mine:** Sued-Chemie AG → Hephzibah Plant; 1985-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sued-Chemie AG → Albion Kaolin Company; 1985-01-23 to 2000-06-20; source msha-controller-operator-history
- **operator_operates_mine:** Covia Holdings Corporation → Hephzibah Plant; 2000-06-21 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Covia Holdings Corporation; 2000-06-21 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Hephzibah Plant; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Covia Holdings Corporation; 2021-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Covia Clay LLC → Hephzibah Plant; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Covia Clay LLC; 2021-01-01 to current/open; source msha-controller-operator-history