# Relationship history for MSHA mine 2100790

Current hierarchy: **Covia Holdings LLC → Covia Solutions LLC → Ottawa 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 → Ottawa Plant; 1950-01-01 to 2020-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Unimin Minnesota Corporation → Ottawa Plant; 1950-01-01 to 2011-05-12; source msha-controller-operator-history
- **controller_controls_mine:** S C R-Sibelco Nv et al → Ottawa Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Unimin Minnesota Corporation; 1950-01-01 to 2011-05-12; source msha-controller-operator-history
- **operator_operates_mine:** Covia Solutions Inc. → Ottawa Plant; 2011-05-13 to 2024-07-31; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Covia Solutions Inc.; 2011-05-13 to 2020-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Ottawa 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 → Ottawa Plant; 2024-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Covia Holdings LLC → Ottawa 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