# Relationship history for MSHA mine 1512049

Current hierarchy: **Brock Wayne → Brock Coal Company → No 1**

- 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:** Ironwood Coal Company Inc → No 1; 1979-09-01 to 1980-09-04; source msha-controller-operator-history
- **controller_controls_mine:** Brown Grant → No 1; 1979-09-01 to 1980-09-04; source msha-controller-operator-history
- **controller_controls_operator:** Brown Grant → Ironwood Coal Company Inc; 1979-09-01 to 1980-09-04; source msha-controller-operator-history
- **operator_operates_mine:** H C Coal Company → No 1; 1980-09-05 to 1984-04-14; source msha-controller-operator-history
- **controller_controls_mine:** Gibson Mitchell → No 1; 1980-09-05 to 1984-04-14; source msha-controller-operator-history
- **controller_controls_operator:** Gibson Mitchell → H C Coal Company; 1980-09-05 to 1984-04-14; source msha-controller-operator-history
- **operator_operates_mine:** Wagon Fork Coal Company → No 1; 1984-04-15 to 1987-04-21; source msha-controller-operator-history
- **controller_controls_mine:** Gibson Anthony D → No 1; 1984-04-15 to 1987-04-21; source msha-controller-operator-history
- **controller_controls_operator:** Gibson Anthony D → Wagon Fork Coal Company; 1984-04-15 to 1987-04-21; source msha-controller-operator-history
- **operator_operates_mine:** Brock Coal Company → No 1; 1987-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brock Wayne → No 1; 1987-04-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brock Wayne → Brock Coal Company; 1987-04-22 to current/open; source msha-controller-operator-history