# Relationship history for MSHA mine 4801375

Current hierarchy: **Hanson PLC → Powder River Coal Company → North Antelope 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:** Powder River Coal Co & Pan Eastern Coal Co → North Antelope Mine; 1980-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → North Antelope Mine; 1981-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** North Antelope Coal Company → North Antelope Mine; 1982-10-01 to 1989-01-31; source msha-controller-operator-history
- **controller_controls_operator:** Powder River Coal Co & Pan Eastern Coal Co → North Antelope Coal Company; 1982-10-01 to 1989-01-31; source msha-controller-operator-history
- **operator_operates_mine:** Powder River Coal Company → North Antelope Mine; 1989-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Powder River Coal Company; 1989-02-01 to current/open; source msha-controller-operator-history