# Relationship history for MSHA mine 2101600

Current hierarchy: **Cleveland Cliffs Inc; US Steel → Hibbing Taconite Company → Hibbing Taconite Company**

- 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:** Hibbing Taconite Company → Hibbing Taconite Company; 1950-01-01 to 2020-12-08; source msha-controller-operator-history
- **controller_controls_mine:** Mittal-US Steel Canada-Cliffs Natural Resources → Hibbing Taconite Company; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mittal-US Steel Canada-Cliffs Natural Resources → Hibbing Taconite Company; 1950-01-01 to 2020-12-08; source msha-controller-operator-history
- **operator_operates_mine:** Hibbing Taconite Company → Hibbing Taconite Company; 2020-12-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cleveland Cliffs Inc et al → Hibbing Taconite Company; 2020-12-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cleveland Cliffs Inc et al → Hibbing Taconite Company; 2020-12-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** US Steel  et al → Hibbing Taconite Company; 2020-12-09 to current/open; source msha-controller-operator-history