# Relationship history for MSHA mine 1512709

Current hierarchy: **Horizon Natural Resources Incorporated → Addington Inc → Job No 15**

- 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:** Blackburn Coal Corp → Job No 15; 1981-01-01 to 1985-03-26; source msha-controller-operator-history
- **controller_controls_mine:** Blackburn G C → Job No 15; 1981-01-01 to 1986-06-01; source msha-controller-operator-history
- **controller_controls_operator:** Blackburn G C → Blackburn Coal Corp; 1981-01-01 to 1985-03-26; source msha-controller-operator-history
- **controller_controls_mine:** Horizon Natural Resources Incorporated → Job No 15; 1983-08-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blackburn Coal Corp → Job No 15; 1985-03-27 to 1985-08-13; source msha-controller-operator-history
- **controller_controls_mine:** Abernathy John K → Job No 15; 1985-03-27 to 1985-08-13; source msha-controller-operator-history
- **controller_controls_operator:** Abernathy John K → Blackburn Coal Corp; 1985-03-27 to 1985-08-13; source msha-controller-operator-history
- **operator_operates_mine:** Blackburn Coal Corp → Job No 15; 1985-08-14 to 1986-06-01; source msha-controller-operator-history
- **controller_controls_operator:** Blackburn G C → Blackburn Coal Corp; 1985-08-14 to 1986-06-01; source msha-controller-operator-history
- **operator_operates_mine:** Addington Inc → Job No 15; 1986-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horizon Natural Resources Incorporated → Addington Inc; 1986-06-02 to current/open; source msha-controller-operator-history