# Relationship history for MSHA mine 3402198

Current hierarchy: **Heidelberg Materials AG → Heidelberg Materials Southwest LLC → Mill Creek 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Hanson PLC → Mill Creek Quarry; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Mill Creek Quarry; 2007-08-23 to 2021-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Hanson Aggregates LLC → Mill Creek Quarry; 2019-10-04 to 2023-04-24; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Hanson Aggregates LLC; 2019-10-04 to 2021-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Hanson Aggregates LLC; 2019-10-04 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Mill Creek Quarry; 2021-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Mill Creek Quarry; 2021-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Hanson Aggregates LLC; 2021-10-01 to 2023-04-24; source msha-controller-operator-history
- **operator_operates_mine:** Heidelberg Materials Southwest LLC → Mill Creek Quarry; 2023-04-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Heidelberg Materials Southwest LLC; 2023-04-25 to current/open; source msha-controller-operator-history