# Relationship history for MSHA mine 1509977

Current hierarchy: **Maynard Mack → Beech Tree Coal Co Inc → No 5 Mine**

- 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:** Maynard Mack → No 5 Mine; 1975-01-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Sowards & Rogers Coal Co Inc → No 5 Mine; 1976-09-24 to 1977-04-17; source msha-controller-operator-history
- **controller_controls_mine:** Sowards Estil → No 5 Mine; 1976-09-24 to 1977-04-17; source msha-controller-operator-history
- **controller_controls_operator:** Sowards Estil → Sowards & Rogers Coal Co Inc; 1976-09-24 to 1977-04-17; source msha-controller-operator-history
- **operator_operates_mine:** Beech Tree Coal Co Inc → No 5 Mine; 1977-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Maynard Mack → Beech Tree Coal Co Inc; 1977-04-18 to current/open; source msha-controller-operator-history