# Relationship history for MSHA mine 5400250

Current hierarchy: **Arturo  Diaz Jr → Best Contracting Corp → Best-Ramirez & Carbo**

- 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

- **controller_controls_mine:** Arturo  Diaz Jr → Best-Ramirez & Carbo; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ramirez & Carbo Inc → Best-Ramirez & Carbo; 1980-04-01 to 1982-11-08; source msha-controller-operator-history
- **controller_controls_mine:** Ramirez Jose Nelson → Best-Ramirez & Carbo; 1980-04-01 to 1982-11-08; source msha-controller-operator-history
- **controller_controls_operator:** Ramirez Jose Nelson → Ramirez & Carbo Inc; 1980-04-01 to 1982-11-08; source msha-controller-operator-history
- **operator_operates_mine:** Best Contracting Corp → Best-Ramirez & Carbo; 1982-11-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arturo  Diaz Jr → Best Contracting Corp; 1982-11-09 to current/open; source msha-controller-operator-history