# Relationship history for MSHA mine 2000061

Current hierarchy: **Carmeuse Holding SA → O-N Minerals (Michigan) Company → O-N Minerals, Cedarville Operation**

- 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

- **operator_operates_mine:** Usx Corp → O-N Minerals, Cedarville Operation; 1950-01-01 to 1987-09-21; source msha-controller-operator-history
- **controller_controls_mine:** USX Corp (United States Steel Corp) → O-N Minerals, Cedarville Operation; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USX Corp (United States Steel Corp) → Usx Corp; 1950-01-01 to 1987-09-21; source msha-controller-operator-history
- **operator_operates_mine:** Michigan Limestone Operations-Ltd Partnership → O-N Minerals, Cedarville Operation; 1987-09-22 to 2000-04-17; source msha-controller-operator-history
- **controller_controls_mine:** Michigan Mnrls Associates Inc  et al → O-N Minerals, Cedarville Operation; 1987-09-22 to 2000-04-17; source msha-controller-operator-history
- **controller_controls_operator:** Michigan Mnrls Associates Inc  et al → Michigan Limestone Operations-Ltd Partnership; 1987-09-22 to 2000-04-17; source msha-controller-operator-history
- **controller_controls_mine:** Oglebay Norton Company → O-N Minerals, Cedarville Operation; 1998-04-27 to 2008-02-12; source msha-controller-operator-history
- **operator_operates_mine:** O-N Minerals (Michigan) Company → O-N Minerals, Cedarville Operation; 2000-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Oglebay Norton Company → O-N Minerals (Michigan) Company; 2000-04-18 to 2008-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Carmeuse Holding SA → O-N Minerals, Cedarville Operation; 2008-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carmeuse Holding SA → O-N Minerals (Michigan) Company; 2008-02-13 to current/open; source msha-controller-operator-history