# Relationship history for MSHA mine 3101518

Current hierarchy: **Covia Holdings LLC → Covia Solutions LLC → Marston 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 → Marston Plant; 1950-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Carolina Silica Inc → Marston Plant; 1950-01-01 to 1983-03-16; source msha-controller-operator-history
- **controller_controls_mine:** W C  Boren III → Marston Plant; 1950-01-01 to 1983-03-16; source msha-controller-operator-history
- **controller_controls_operator:** W C  Boren III → Carolina Silica Inc; 1950-01-01 to 1983-03-16; source msha-controller-operator-history
- **operator_operates_mine:** Covia Solutions Inc. → Marston Plant; 1983-03-17 to 2024-07-31; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Covia Solutions Inc.; 1983-03-17 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Marston Plant; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Covia Solutions Inc.; 2021-01-01 to 2024-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Covia Solutions LLC → Marston Plant; 2024-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Marston Plant; 2024-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Covia Holdings LLC → Covia Solutions LLC; 2024-08-01 to current/open; source msha-controller-operator-history