# Relationship history for MSHA mine 1508148

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

- **controller_controls_mine:** Occidental Petroleum Corp → Rainey No 1 Surface Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Wales Corp → Rainey No 1 Surface Mine; 1975-03-01 to 1976-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Walsh David E & Richard → Rainey No 1 Surface Mine; 1975-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Walsh David E & Richard → Wales Corp; 1975-03-01 to 1976-03-31; source msha-controller-operator-history
- **operator_operates_mine:** Island Creek Coal Company → Rainey No 1 Surface Mine; 1976-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Occidental Petroleum Corp → Island Creek Coal Company; 1976-04-01 to current/open; source msha-controller-operator-history