# Relationship history for MSHA mine 0500425

Current hierarchy: **Amrize Ltd → Holcim (US) Inc → Coaldale Gypsum 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Flintkote Company → Coaldale Gypsum Quarry; 1950-01-01 to 1980-04-06; source msha-controller-operator-history
- **controller_controls_mine:** Flintkote Company → Coaldale Gypsum Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Flintkote Company → Flintkote Company; 1950-01-01 to 1980-04-06; source msha-controller-operator-history
- **operator_operates_mine:** Genstar Building Materials Company → Coaldale Gypsum Quarry; 1980-04-07 to 1987-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Cimenteries Cbr Cementbedrijven → Coaldale Gypsum Quarry; 1980-04-07 to 1987-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Cimenteries Cbr Cementbedrijven → Genstar Building Materials Company; 1980-04-07 to 1987-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Domtar Inc → Coaldale Gypsum Quarry; 1983-10-31 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Domtar Gypsum Inc → Coaldale Gypsum Quarry; 1987-03-01 to 2007-05-30; source msha-controller-operator-history
- **controller_controls_operator:** Domtar Inc → Domtar Gypsum Inc; 1987-03-01 to 2007-05-30; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Coaldale Gypsum Quarry; 2001-12-12 to 2015-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Holcim (US) Inc → Coaldale Gypsum Quarry; 2007-05-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Holcim (US) Inc; 2007-05-31 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Coaldale Gypsum Quarry; 2015-07-10 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Holcim (US) Inc; 2015-07-10 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_mine:** Amrize Ltd → Coaldale Gypsum Quarry; 2025-06-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amrize Ltd → Holcim (US) Inc; 2025-06-23 to current/open; source msha-controller-operator-history