# Relationship history for MSHA mine 1507967

Current hierarchy: **Burchett Delbert → Shiloh Coal Corp → No 1 Surface**

- 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:** Armstrong M G → No 1 Surface; 1974-01-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dorsa Industries Inc → No 1 Surface; 1974-01-07 to 1977-08-01; source msha-controller-operator-history
- **controller_controls_operator:** Armstrong M G → Dorsa Industries Inc; 1974-01-07 to 1977-08-01; source msha-controller-operator-history
- **operator_operates_mine:** Shiloh Coal Corp → No 1 Surface; 1977-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Burchett Delbert → No 1 Surface; 1977-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Burchett Delbert → Shiloh Coal Corp; 1977-08-02 to current/open; source msha-controller-operator-history