# Relationship history for MSHA mine 3001186

Current hierarchy: **Heidelberg Materials AG → HEIDELBERG MATERIALS NORTHEAST LLC → POLAND PLANT**

- 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:** Koppers Company Inc → POLAND PLANT; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Special Aggregates Corp → POLAND PLANT; 1950-01-01 to 1979-08-20; source msha-controller-operator-history
- **controller_controls_mine:** Edward  Hayes → POLAND PLANT; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edward  Hayes → Special Aggregates Corp; 1950-01-01 to 1979-08-20; source msha-controller-operator-history
- **operator_operates_mine:** Poland Sand Corp → POLAND PLANT; 1979-08-21 to 1983-10-06; source msha-controller-operator-history
- **controller_controls_mine:** Edward T Wood → POLAND PLANT; 1979-08-21 to 1983-10-06; source msha-controller-operator-history
- **controller_controls_operator:** Edward T Wood → Poland Sand Corp; 1979-08-21 to 1983-10-06; source msha-controller-operator-history
- **operator_operates_mine:** Eastern Rock Products Inc → POLAND PLANT; 1983-10-07 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Eastern Rock Products Inc; 1983-10-07 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Heidelberg Materials Northeast-NY LLC → POLAND PLANT; 1988-11-14 to 2025-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → POLAND PLANT; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Heidelberg Materials Northeast-NY LLC; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → POLAND PLANT; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Heidelberg Materials Northeast-NY LLC; 2007-08-23 to 2025-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Heidelberg Materials Northeast LLC → POLAND PLANT; 2025-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Heidelberg Materials Northeast LLC; 2025-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Heidelberg Materials Northeast LLC; 2025-05-01 to 2007-08-22; source msha-controller-operator-history