# Relationship history for MSHA mine 1202117

Current hierarchy: **Carmeuse Holding SA → O-N Minerals Portage Company LLC → Portage 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

- **controller_controls_mine:** J M Huber Corp → Portage Operation; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** J M Huber Corp → Portage Operation; 1992-02-01 to 2000-09-12; source msha-controller-operator-history
- **controller_controls_operator:** J M Huber Corp → J M Huber Corp; 1992-02-01 to 2000-09-12; source msha-controller-operator-history
- **operator_operates_mine:** O-N Minerals Portage Company LLC → Portage Operation; 2000-09-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Oglebay Norton Company → Portage Operation; 2000-09-13 to 2008-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Oglebay Norton Company → O-N Minerals Portage Company LLC; 2000-09-13 to 2008-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Carmeuse Holding SA → Portage Operation; 2008-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carmeuse Holding SA → O-N Minerals Portage Company LLC; 2008-02-13 to current/open; source msha-controller-operator-history