# Relationship history for MSHA mine 1508571

Current hierarchy: **Maynard Mack → Beech Tree Coal Co Inc → No 3**

- 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 3; 1975-01-06 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Beech Tree Coal Co Inc → No 3; 1975-07-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Maynard Mack → Beech Tree Coal Co Inc; 1975-07-23 to current/open; source msha-controller-operator-history