# Relationship history for MSHA mine 0503193

Current hierarchy: **Massey Energy Company → Anchor Coal Company Inc → Windjammer #1 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Anchor Coal Company Inc → Windjammer #1 Mine; 1978-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → Windjammer #1 Mine; 1978-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Anchor Coal Company Inc; 1978-09-01 to current/open; source msha-controller-operator-history