# Relationship history for MSHA mine 4103929

Current hierarchy: **Covia Holdings LLC → Covia Holdings Corporaton → Voca 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

- **controller_controls_mine:** S C R-Sibelco Nv et al → Voca Plant; 1950-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Covia Holdings Corporaton → Voca Plant; 1996-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Covia Holdings Corporaton; 1996-09-01 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Voca Plant; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Covia Holdings Corporaton; 2021-01-01 to current/open; source msha-controller-operator-history