# Relationship history for MSHA mine 4604642

Current hierarchy: **Hanson PLC → Peabody Coal Company → Copeland 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:** Allied Chemical Corp → Copeland Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Armco Inc → Copeland Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Copeland Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Allied Chemical Corp-Semet Solvay Div → Copeland Mine; 1975-05-21 to 1980-01-08; source msha-controller-operator-history
- **controller_controls_operator:** Allied Chemical Corp → Allied Chemical Corp-Semet Solvay Div; 1975-05-21 to 1980-01-08; source msha-controller-operator-history
- **operator_operates_mine:** Armco Inc → Copeland Mine; 1980-01-09 to 1984-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Armco Inc → Armco Inc; 1980-01-09 to 1984-02-26; source msha-controller-operator-history
- **operator_operates_mine:** Peabody Coal Company → Copeland Mine; 1984-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Peabody Coal Company; 1984-02-27 to current/open; source msha-controller-operator-history