# Relationship history for MSHA mine 0800919

Current hierarchy: **Hanson PLC → Cherokee Crushed Stone Inc → Cherokee Quarry**

- 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

- **operator_operates_mine:** Cherokee Crushed Stone Inc → Cherokee Quarry; 1979-01-01 to 1981-06-14; source msha-controller-operator-history
- **controller_controls_mine:** Badgett Brown Jr → Cherokee Quarry; 1979-01-01 to 1981-06-14; source msha-controller-operator-history
- **controller_controls_operator:** Badgett Brown Jr → Cherokee Crushed Stone Inc; 1979-01-01 to 1981-06-14; source msha-controller-operator-history
- **operator_operates_mine:** Cherokee Crushed Stone Inc → Cherokee Quarry; 1981-06-15 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Koppers Company Inc → Cherokee Quarry; 1981-06-15 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Cherokee Crushed Stone Inc; 1981-06-15 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Cherokee Crushed Stone Inc → Cherokee Quarry; 1988-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Cherokee Quarry; 1988-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Cherokee Crushed Stone Inc; 1988-11-14 to current/open; source msha-controller-operator-history