# Relationship history for MSHA mine 1512531

Current hierarchy: **Horizon Natural Resources Incorporated → Addington Inc → Job #7**

- 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:** Kiawa Coal Company → Job #7; 1980-08-01 to 1983-08-08; source msha-controller-operator-history
- **controller_controls_mine:** Pierce Otis → Job #7; 1980-08-01 to 1983-08-08; source msha-controller-operator-history
- **controller_controls_operator:** Pierce Otis → Kiawa Coal Company; 1980-08-01 to 1983-08-08; source msha-controller-operator-history
- **operator_operates_mine:** Addington Inc → Job #7; 1983-08-09 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Horizon Natural Resources Incorporated → Job #7; 1983-08-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Horizon Natural Resources Incorporated → Addington Inc; 1983-08-09 to current/open; source msha-controller-operator-history