# Relationship history for MSHA mine 4605055

Current hierarchy: **Zeigler Coal Holding Company → Western Mingo Coal Company → Left Fork 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:** Western Mingo Coal Company → Left Fork Mine; 1950-01-01 to 1987-09-11; source msha-controller-operator-history
- **controller_controls_mine:** Massey Energy Company → Left Fork Mine; 1950-01-01 to 1989-02-06; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Western Mingo Coal Company; 1950-01-01 to 1987-09-11; source msha-controller-operator-history
- **operator_operates_mine:** Western Mingo Coal Company → Left Fork Mine; 1987-09-12 to 1992-11-23; source msha-controller-operator-history
- **controller_controls_mine:** Shell Oil Company → Left Fork Mine; 1987-09-12 to 1992-11-23; source msha-controller-operator-history
- **controller_controls_operator:** Shell Oil Company → Western Mingo Coal Company; 1987-09-12 to 1992-11-23; source msha-controller-operator-history
- **operator_operates_mine:** Western Mingo Coal Company → Left Fork Mine; 1992-11-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Zeigler Coal Holding Company → Left Fork Mine; 1992-11-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zeigler Coal Holding Company → Western Mingo Coal Company; 1992-11-24 to current/open; source msha-controller-operator-history