# Relationship history for MSHA mine 4602210

Current hierarchy: **Massey Energy Company → Royalty Smokeless Coal Company Inc → #8 Preparation Plant**

- 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:** Royalty Smokeless Coal Company Inc → #8 Preparation Plant; 1950-01-01 to 1985-09-08; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → #8 Preparation Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Royalty Smokeless Coal Company Inc; 1950-01-01 to 1985-09-08; source msha-controller-operator-history
- **operator_operates_mine:** Soho Coal Company Inc → #8 Preparation Plant; 1985-09-09 to 1990-01-30; source msha-controller-operator-history
- **controller_controls_mine:** Ted  Osborne  et al → #8 Preparation Plant; 1985-09-09 to 1990-01-30; source msha-controller-operator-history
- **controller_controls_operator:** Ted  Osborne  et al → Soho Coal Company Inc; 1985-09-09 to 1990-01-30; source msha-controller-operator-history
- **operator_operates_mine:** Royalty Smokeless Coal Company Inc → #8 Preparation Plant; 1990-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Royalty Smokeless Coal Company Inc; 1990-01-31 to current/open; source msha-controller-operator-history