# Relationship history for MSHA mine 4608034

Current hierarchy: **Massey Energy Company → Williams Mountain Coal Company → Black Oak**

- 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

- **controller_controls_mine:** Richard H  Abraham et al → Black Oak; 1977-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wynchester Mining Company Inc → Black Oak; 1991-05-01 to 1993-12-22; source msha-controller-operator-history
- **controller_controls_operator:** Richard H  Abraham et al → Wynchester Mining Company Inc; 1991-05-01 to 1993-12-22; source msha-controller-operator-history
- **operator_operates_mine:** Williams Mountain Coal Company → Black Oak; 1993-12-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → Black Oak; 1993-12-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Williams Mountain Coal Company; 1993-12-23 to current/open; source msha-controller-operator-history