# Relationship history for MSHA mine 4606235

Current hierarchy: **Occidental Petroleum Corp → Island Creek Coal Company → Guyan 1d**

- 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:** Occidental Petroleum Corp → Guyan 1d; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hatfield Ewell & Marcus C → Guyan 1d; 1979-05-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Perry Branch Coal Company → Guyan 1d; 1980-10-01 to 1984-09-17; source msha-controller-operator-history
- **controller_controls_operator:** Hatfield Ewell & Marcus C → Perry Branch Coal Company; 1980-10-01 to 1984-09-17; source msha-controller-operator-history
- **operator_operates_mine:** Island Creek Coal Company → Guyan 1d; 1984-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Occidental Petroleum Corp → Island Creek Coal Company; 1984-09-18 to current/open; source msha-controller-operator-history