# Relationship history for MSHA mine 2101152

Current hierarchy: **Cleveland-Cliffs Inc → Pickands Mather Services Inc → Hibbing Laboratory**

- 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

- **operator_operates_mine:** Pickands Mather Services Inc → Hibbing Laboratory; 1950-01-01 to 1986-12-29; source msha-controller-operator-history
- **controller_controls_mine:** Moore Mc Cormack Resources Inc → Hibbing Laboratory; 1950-01-01 to 1986-12-29; source msha-controller-operator-history
- **controller_controls_operator:** Moore Mc Cormack Resources Inc → Pickands Mather Services Inc; 1950-01-01 to 1986-12-29; source msha-controller-operator-history
- **operator_operates_mine:** Pickands Mather Services Inc → Hibbing Laboratory; 1986-12-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cleveland-Cliffs Inc → Hibbing Laboratory; 1986-12-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cleveland-Cliffs Inc → Pickands Mather Services Inc; 1986-12-30 to current/open; source msha-controller-operator-history