# Relationship history for MSHA mine 0404894

Current hierarchy: **Heidelberg Materials AG → Hanson Aggregates Pacific Southwest Inc → UNIVERSITY - SAN MARCOS 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

- **controller_controls_mine:** Koppers Company Inc → UNIVERSITY - SAN MARCOS QUARRY; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → UNIVERSITY - SAN MARCOS QUARRY; 1987-05-01 to 2007-08-22; source msha-controller-operator-history
- **operator_operates_mine:** South Coast Asphalt Products Company → UNIVERSITY - SAN MARCOS QUARRY; 1987-08-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → South Coast Asphalt Products Company; 1987-08-01 to 1988-11-13; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates Pacific Southwest Inc → UNIVERSITY - SAN MARCOS QUARRY; 1988-11-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates Pacific Southwest Inc; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → UNIVERSITY - SAN MARCOS QUARRY; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Aggregates Pacific Southwest Inc; 2007-08-23 to current/open; source msha-controller-operator-history