# Relationship history for MSHA mine 2100286

Current hierarchy: **LTV Corp → Ltv Steel Company Inc → Northwest Ore Div/Mc Kinley Extension Mi**

- 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:** United States Steel Corp → Northwest Ore Div/Mc Kinley Extension Mi; 1950-01-01 to 1982-07-19; source msha-controller-operator-history
- **controller_controls_mine:** USX Corp (United States Steel Corp) → Northwest Ore Div/Mc Kinley Extension Mi; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USX Corp (United States Steel Corp) → United States Steel Corp; 1950-01-01 to 1982-07-19; source msha-controller-operator-history
- **operator_operates_mine:** Ltv Steel Company Inc → Northwest Ore Div/Mc Kinley Extension Mi; 1982-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** LTV Corp → Northwest Ore Div/Mc Kinley Extension Mi; 1982-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** LTV Corp → Ltv Steel Company Inc; 1982-07-20 to current/open; source msha-controller-operator-history