# Relationship history for MSHA mine 1513888

Current hierarchy: **Sunoco, Inc. → Shamrock Coal Company Inc → Greenwood No 7 Mine**

- 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

- **controller_controls_mine:** Sunoco, Inc. → Greenwood No 7 Mine; 1979-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Shamrock Coal Company Inc → Greenwood No 7 Mine; 1983-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sunoco, Inc. → Shamrock Coal Company Inc; 1983-01-01 to current/open; source msha-controller-operator-history