# Relationship history for MSHA mine 2200740

Current hierarchy: **CRH PLC → APAC-MS, INC. → COXBURG SAND & GRAVEL**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Ashland Inc → COXBURG SAND & GRAVEL; 1950-01-01 to 2006-08-27; source msha-controller-operator-history
- **controller_controls_mine:** Harold P  Hammett Jr  et al → COXBURG SAND & GRAVEL; 1950-01-01 to 2019-08-15; source msha-controller-operator-history
- **operator_operates_mine:** Hammett Gravel Company Inc → COXBURG SAND & GRAVEL; 2001-06-01 to 2024-11-07; source msha-controller-operator-history
- **controller_controls_operator:** Harold P  Hammett Jr  et al → Hammett Gravel Company Inc; 2001-06-01 to 2019-08-15; source msha-controller-operator-history
- **controller_controls_operator:** Heyward C  Green  et al → Hammett Gravel Company Inc; 2001-06-01 to 2019-08-15; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → COXBURG SAND & GRAVEL; 2006-08-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harold P  Hammett Jr → COXBURG SAND & GRAVEL; 2019-08-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harold P  Hammett Jr → Hammett Gravel Company Inc; 2019-08-16 to 2024-11-07; source msha-controller-operator-history
- **operator_operates_mine:** APAC-MS, INC. → COXBURG SAND & GRAVEL; 2024-11-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ashland Inc → APAC-MS, INC.; 2024-11-08 to 2006-08-27; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → APAC-MS, INC.; 2024-11-08 to current/open; source msha-controller-operator-history