# Relationship history for MSHA mine 2103352

Current hierarchy: **USX Corp (United States Steel Corp) → United States Steel Corp-Minnesota Ore Operations → Keetac**

- 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:** USX Corp (United States Steel Corp) → Keetac; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** United States Steel Corp-Minnesota Ore Operations → Keetac; 2003-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** USX Corp (United States Steel Corp) → United States Steel Corp-Minnesota Ore Operations; 2003-05-20 to current/open; source msha-controller-operator-history