# Relationship history for MSHA mine 2000051

Current hierarchy: **Amrize Ltd → Amrize Great Lakes Inc. → Amrize Presque Isle 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Presque Isle Corp → Amrize Presque Isle Aggregates; 1950-01-01 to 2000-06-30; source msha-controller-operator-history
- **controller_controls_mine:** LTV Steel Co et al → Amrize Presque Isle Aggregates; 1950-01-01 to 2000-06-30; source msha-controller-operator-history
- **controller_controls_operator:** LTV Steel Co et al → Presque Isle Corp; 1950-01-01 to 2000-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Amrize Presque Isle Aggregates; 1998-02-11 to 2015-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Presque Isle Corp → Amrize Presque Isle Aggregates; 2000-07-01 to 2010-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Amrize Presque Isle Aggregates; 2000-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Presque Isle Corp; 2000-07-01 to 2010-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Amrize Presque Isle Aggregates; 2001-07-12 to 2015-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge North America Inc. → Amrize Presque Isle Aggregates; 2010-11-01 to 2022-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge North America Inc.; 2010-11-01 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Amrize Presque Isle Aggregates; 2015-07-10 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Amrize Presque Isle 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 2022-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Amrize Great Lakes Inc. → Amrize Presque Isle Aggregates; 2022-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Amrize Great Lakes Inc.; 2022-05-01 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Amrize Great Lakes Inc.; 2022-05-01 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Amrize Ltd → Amrize Presque Isle 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