# Relationship history for MSHA mine 2900450

Current hierarchy: **CRH PLC → Four Corners Materials → FCM Portable Crusher**

- 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:** Farmington Sand & Gravel → FCM Portable Crusher; 1950-01-01 to 2017-06-29; source msha-controller-operator-history
- **controller_controls_mine:** Stanley Kozimor Trust B"" → FCM Portable Crusher; 1950-01-01 to 2014-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Stanley Kozimor Trust B"" → Farmington Sand & Gravel; 1950-01-01 to 2014-03-31; source msha-controller-operator-history
- **controller_controls_mine:** CRH PLC → FCM Portable Crusher; 1998-01-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joe  Kozimor et al → FCM Portable Crusher; 2014-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joe  Kozimor et al → Farmington Sand & Gravel; 2014-04-01 to 2017-06-29; source msha-controller-operator-history
- **controller_controls_operator:** Stan  Kozimor et al → Farmington Sand & Gravel; 2014-04-01 to 2017-06-29; source msha-controller-operator-history
- **operator_operates_mine:** Four Corners Materials → FCM Portable Crusher; 2017-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Four Corners Materials; 2017-06-30 to current/open; source msha-controller-operator-history