# Relationship history for MSHA mine 4603144

Current hierarchy: **Bethlehem Steel Corp → Bethlehem Mines Corp → No 46 Prep Plant**

- 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

- **controller_controls_mine:** Bethlehem Steel Corp → No 46 Prep Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bethlehem Mines Corp → No 46 Prep Plant; 1972-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bethlehem Steel Corp → Bethlehem Mines Corp; 1972-04-02 to current/open; source msha-controller-operator-history