# Relationship history for MSHA mine 1505301

Current hierarchy: **Zeigler Coal Holding Company → Utility Coals Company → Utility 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:** Utility Coals Inc → Utility Preparation Plant; 1950-01-01 to 1987-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → Utility Preparation Plant; 1950-01-01 to 1987-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Utility Coals Inc; 1950-01-01 to 1987-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Utility Coals Company → Utility Preparation Plant; 1987-07-10 to 1993-01-24; source msha-controller-operator-history
- **controller_controls_mine:** Shell Oil Company → Utility Preparation Plant; 1987-07-10 to 1993-01-24; source msha-controller-operator-history
- **controller_controls_operator:** Shell Oil Company → Utility Coals Company; 1987-07-10 to 1993-01-24; source msha-controller-operator-history
- **operator_operates_mine:** Utility Coals Company → Utility Preparation Plant; 1993-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Zeigler Coal Holding Company → Utility Preparation Plant; 1993-01-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zeigler Coal Holding Company → Utility Coals Company; 1993-01-25 to current/open; source msha-controller-operator-history