# Relationship history for MSHA mine 1512609

Current hierarchy: **Embry Royce → Dunbar Coal Company Inc → Black Bullett**

- 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

- **operator_operates_mine:** Dunbar Coal Company Inc → Black Bullett; 1980-10-01 to 1983-09-26; source msha-controller-operator-history
- **controller_controls_mine:** Coleman Denzil → Black Bullett; 1980-10-01 to 1983-09-26; source msha-controller-operator-history
- **controller_controls_operator:** Coleman Denzil → Dunbar Coal Company Inc; 1980-10-01 to 1983-09-26; source msha-controller-operator-history
- **operator_operates_mine:** Dunbar Coal Company Inc → Black Bullett; 1983-09-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Embry Royce → Black Bullett; 1983-09-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Embry Royce → Dunbar Coal Company Inc; 1983-09-27 to current/open; source msha-controller-operator-history