# Relationship history for MSHA mine 0503301

Current hierarchy: **Amrize Ltd → Aggregate Industries WCR Inc → THORNTON PLANT**

- 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:** J L Shiely  Company → THORNTON PLANT; 1950-01-01 to 1988-07-18; source msha-controller-operator-history
- **operator_operates_mine:** Cooley Gravel Company → THORNTON PLANT; 1979-01-01 to 1988-07-18; source msha-controller-operator-history
- **controller_controls_operator:** J L Shiely  Company → Cooley Gravel Company; 1979-01-01 to 1988-07-18; source msha-controller-operator-history
- **operator_operates_mine:** Cooley Gravel Company → THORNTON PLANT; 1988-07-19 to 1994-07-31; source msha-controller-operator-history
- **controller_controls_mine:** English China Clays PLC → THORNTON PLANT; 1988-07-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** English China Clays PLC → Cooley Gravel Company; 1988-07-19 to 1994-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Cooley Gravel Company → THORNTON PLANT; 1994-08-01 to 1997-05-13; source msha-controller-operator-history
- **controller_controls_mine:** Camas Plc → THORNTON PLANT; 1994-08-01 to 1997-05-13; source msha-controller-operator-history
- **controller_controls_operator:** Camas Plc → Cooley Gravel Company; 1994-08-01 to 1997-05-13; source msha-controller-operator-history
- **operator_operates_mine:** Aggregate Industries WCR Inc → THORNTON PLANT; 1997-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Aggregate Industries PLC → THORNTON PLANT; 1997-05-14 to 2009-04-29; source msha-controller-operator-history
- **controller_controls_operator:** Aggregate Industries PLC → Aggregate Industries WCR Inc; 1997-05-14 to 2009-04-29; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → THORNTON PLANT; 2009-04-30 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Aggregate Industries WCR Inc; 2009-04-30 to 2015-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → THORNTON PLANT; 2015-07-10 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Aggregate Industries WCR Inc; 2015-07-10 to 2025-06-22; source msha-controller-operator-history
- **controller_controls_mine:** Amrize Ltd → THORNTON PLANT; 2025-06-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Amrize Ltd → Aggregate Industries WCR Inc; 2025-06-23 to current/open; source msha-controller-operator-history