# Relationship history for MSHA mine 1202179

Current hierarchy: **Heidelberg Materials AG → Heidelberg Materials Midwest Agg, Inc. → Aggrock 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 → Aggrock Quarry; 1988-11-14 to 2007-08-22; source msha-controller-operator-history
- **operator_operates_mine:** Aggrock Quarries Inc → Aggrock Quarry; 1995-04-01 to 2000-09-17; source msha-controller-operator-history
- **controller_controls_mine:** Dan  Cristiani → Aggrock Quarry; 1995-04-01 to 2000-09-17; source msha-controller-operator-history
- **controller_controls_operator:** Dan  Cristiani → Aggrock Quarries Inc; 1995-04-01 to 2000-09-17; source msha-controller-operator-history
- **operator_operates_mine:** Heidelberg Materials Midwest Agg, Inc. → Aggrock Quarry; 2000-09-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hanson PLC → Heidelberg Materials Midwest Agg, Inc.; 2000-09-18 to 2007-08-22; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Aggrock Quarry; 2007-08-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Heidelberg Materials Midwest Agg, Inc.; 2007-08-23 to current/open; source msha-controller-operator-history