# Relationship history for MSHA mine 0405301

Current hierarchy: **Omya Industries Inc → Omya, Inc → Amboy Limestone 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Omya Industries Inc → Amboy Limestone Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Omya California Inc → Amboy Limestone Quarry; 1997-01-01 to 2009-01-22; source msha-controller-operator-history
- **controller_controls_operator:** Omya Industries Inc → Omya California Inc; 1997-01-01 to 2009-01-22; source msha-controller-operator-history
- **operator_operates_mine:** Omya, Inc → Amboy Limestone Quarry; 2009-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Omya Industries Inc → Amboy Limestone Quarry; 2009-01-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Omya Industries Inc → Omya, Inc; 2009-01-23 to current/open; source msha-controller-operator-history