# Relationship history for MSHA mine 4000792

Current hierarchy: **Covia Holdings LLC → Unimin Corp → CAMDEN 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Morie Company Inc → CAMDEN PLANT; 1950-01-01 to 1996-12-02; source msha-controller-operator-history
- **controller_controls_mine:** Energy & Minerals Inc → CAMDEN PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Energy & Minerals Inc → Morie Company Inc; 1950-01-01 to 1996-12-02; source msha-controller-operator-history
- **controller_controls_mine:** S C R-Sibelco Nv et al → CAMDEN PLANT; 1950-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Unimin Corp → CAMDEN PLANT; 1996-12-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Unimin Corp; 1996-12-03 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → CAMDEN PLANT; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Unimin Corp; 2021-01-01 to current/open; source msha-controller-operator-history