# Relationship history for MSHA mine 2800541

Current hierarchy: **CRH PLC → Tilcon New York Inc → Oxford Quarry & Mill**

- 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

- **operator_operates_mine:** Oxford Quarry Inc → Oxford Quarry & Mill; 1950-01-01 to 1999-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Gary A  Mahan  et al → Oxford Quarry & Mill; 1950-01-01 to 1999-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Gary A  Mahan  et al → Oxford Quarry Inc; 1950-01-01 to 1999-06-30; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → Oxford Quarry & Mill; 1996-09-09 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tilcon New York Inc → Oxford Quarry & Mill; 1999-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Tilcon New York Inc; 1999-07-01 to current/open; source msha-controller-operator-history