# Relationship history for MSHA mine 1515364

Current hierarchy: **Zeigler Coal Holding Company → Clark Elkhorn Coal Company → Cedar Creek No 2 Surface**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Massey Energy Company → Cedar Creek No 2 Surface; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Clark Elkhorn Coal Company Inc → Cedar Creek No 2 Surface; 1985-09-01 to 1987-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Massey Energy Company → Clark Elkhorn Coal Company Inc; 1985-09-01 to 1987-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Clark Elkhorn Coal Company → Cedar Creek No 2 Surface; 1987-07-10 to 1992-11-22; source msha-controller-operator-history
- **controller_controls_mine:** Shell Oil Company → Cedar Creek No 2 Surface; 1987-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shell Oil Company → Clark Elkhorn Coal Company; 1987-07-10 to 1992-11-22; source msha-controller-operator-history
- **operator_operates_mine:** Clark Elkhorn Coal Company → Cedar Creek No 2 Surface; 1992-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Zeigler Coal Holding Company → Cedar Creek No 2 Surface; 1992-11-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zeigler Coal Holding Company → Clark Elkhorn Coal Company; 1992-11-23 to current/open; source msha-controller-operator-history