# Relationship history for MSHA mine 0402911

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta San Diego Aggregates, LLC → Miramar Recycle**

- 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

- **operator_operates_mine:** Sim J Harris Company → Miramar Recycle; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Koppers Company Inc → Miramar Recycle; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_operator:** Koppers Company Inc → Sim J Harris Company; 1950-01-01 to 1988-11-13; source msha-controller-operator-history
- **controller_controls_mine:** Hanson PLC → Miramar Recycle; 1987-05-01 to 2007-08-22; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates Pacific Southwest Inc → Miramar Recycle; 1988-11-14 to 2021-09-30; 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 → Miramar Recycle; 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 2021-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta San Diego Aggregates, LLC → Miramar Recycle; 2021-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Miramar Recycle; 2021-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta San Diego Aggregates, LLC; 2021-10-01 to current/open; source msha-controller-operator-history