# Relationship history for MSHA mine 3300099

Current hierarchy: **Amrize Ltd → Amrize Great Lakes Inc. → Amrize Marblehead Aggregates**

- 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:** Standard Slag Company → Amrize Marblehead Aggregates; 1950-01-01 to 1989-11-14; source msha-controller-operator-history
- **controller_controls_mine:** Standard Slag Company → Amrize Marblehead Aggregates; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Standard Slag Company → Standard Slag Company; 1950-01-01 to 1989-11-14; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Amrize Marblehead Aggregates; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Corp → Amrize Marblehead Aggregates; 1989-11-15 to 2001-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Corp; 1989-11-15 to 2001-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Amrize Marblehead Aggregates; 1998-02-11 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Amrize Marblehead Aggregates; 2001-07-12 to 2015-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge North America Inc. → Amrize Marblehead Aggregates; 2001-09-01 to 2018-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge North America Inc.; 2001-09-01 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Amrize Marblehead Aggregates; 2015-07-10 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Amrize Marblehead Aggregates; 2015-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Lafarge North America Inc.; 2015-07-10 to 2018-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Amrize Great Lakes Inc. → Amrize Marblehead Aggregates; 2018-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Amrize Great Lakes Inc.; 2018-09-01 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Amrize Great Lakes Inc.; 2018-09-01 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Amrize Ltd → Amrize Marblehead Aggregates; 2025-06-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amrize Ltd → Amrize Great Lakes Inc.; 2025-06-23 to current/open; source msha-controller-operator-history