# Relationship history for MSHA mine 1513421

Current hierarchy: **Cornett Donald W → Blackfire 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Pluto Mining Company → No 1; 1982-03-01 to 1983-09-01; source msha-controller-operator-history
- **controller_controls_mine:** Taylor Melvin → No 1; 1982-03-01 to 1983-09-01; source msha-controller-operator-history
- **controller_controls_operator:** Taylor Melvin → Pluto Mining Company; 1982-03-01 to 1983-09-01; source msha-controller-operator-history
- **operator_operates_mine:** Blackfire Coal Company → No 1; 1983-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cornett Donald W → No 1; 1983-09-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cornett Donald W → Blackfire Coal Company; 1983-09-02 to current/open; source msha-controller-operator-history