# Relationship history for MSHA mine 2800470

Current hierarchy: **John C  Crimi → County Concrete Corp → Kenvil Pit and 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Houdaille Construction Materials Inc → Kenvil Pit and Mill; 1950-01-01 to 1979-03-14; source msha-controller-operator-history
- **controller_controls_mine:** Houdaille Industries Inc → Kenvil Pit and Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Houdaille Industries Inc → Houdaille Construction Materials Inc; 1950-01-01 to 1979-03-14; source msha-controller-operator-history
- **operator_operates_mine:** County Concrete Corp → Kenvil Pit and Mill; 1979-03-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John C  Crimi → Kenvil Pit and Mill; 1979-03-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John C  Crimi → County Concrete Corp; 1979-03-15 to current/open; source msha-controller-operator-history