# Relationship history for MSHA mine 3601087

Current hierarchy: **Gifford-Hill & Company Inc → Magnum Minerals Inc → Magnum Strips**

- 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:** Lucas Coal Company → Magnum Strips; 1950-01-01 to 1977-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Lucas William A → Magnum Strips; 1950-01-01 to 1977-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Lucas William A → Lucas Coal Company; 1950-01-01 to 1977-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Lucas Coal Company Inc → Magnum Strips; 1977-03-01 to 1979-12-06; source msha-controller-operator-history
- **controller_controls_mine:** Amcord Inc → Magnum Strips; 1977-03-01 to 1979-12-06; source msha-controller-operator-history
- **controller_controls_operator:** Amcord Inc → Lucas Coal Company Inc; 1977-03-01 to 1979-12-06; source msha-controller-operator-history
- **operator_operates_mine:** Magnum Minerals Inc → Magnum Strips; 1979-12-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gifford-Hill & Company Inc → Magnum Strips; 1979-12-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gifford-Hill & Company Inc → Magnum Minerals Inc; 1979-12-07 to current/open; source msha-controller-operator-history