# Relationship history for MSHA mine 4606815

Current hierarchy: **Occidental Petroleum Corp → Island Creek Coal Company → Surface Mine No 1**

- 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 → Surface Mine No 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Silver Creek Mining Inc → Surface Mine No 1; 1984-07-01 to 1986-03-20; source msha-controller-operator-history
- **controller_controls_mine:** Slamen Darlene → Surface Mine No 1; 1984-07-01 to 1986-03-20; source msha-controller-operator-history
- **controller_controls_operator:** Slamen Darlene → Silver Creek Mining Inc; 1984-07-01 to 1986-03-20; source msha-controller-operator-history
- **operator_operates_mine:** Island Creek Coal Company → Surface Mine No 1; 1986-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Occidental Petroleum Corp → Island Creek Coal Company; 1986-03-21 to current/open; source msha-controller-operator-history