# Relationship history for MSHA mine 4605534

Current hierarchy: **Bethlehem Steel Corp → Bethlehem Mines Corp → Mine No 121**

- 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:** Fletcher Herman P → Mine No 121; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bethlehem Steel Corp → Mine No 121; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Fletcher Mining Company Inc → Mine No 121; 1977-07-01 to 1978-07-19; source msha-controller-operator-history
- **controller_controls_operator:** Fletcher Herman P → Fletcher Mining Company Inc; 1977-07-01 to 1978-07-19; source msha-controller-operator-history
- **operator_operates_mine:** Bethlehem Mines Corp → Mine No 121; 1978-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bethlehem Steel Corp → Bethlehem Mines Corp; 1978-07-20 to current/open; source msha-controller-operator-history