# Relationship history for MSHA mine 1517585

Current hierarchy: **Massey Energy Company → Pilgrim Mining Company Inc → Voyager Mine Number One**

- 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:** Massey Energy Company → Voyager Mine Number One; 1987-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pilgrim Mining Company Inc → Voyager Mine Number One; 1994-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Pilgrim Mining Company Inc; 1994-08-01 to current/open; source msha-controller-operator-history