# Relationship history for MSHA mine 3400659

Current hierarchy: **Sam M  Renfro → Renfro Sand & Concrete Company → Renfro**

- 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:** Renfro Sand & Concrete Company → Renfro; 1950-01-01 to 1993-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Marshal  Renfro → Renfro; 1950-01-01 to 1993-12-31; source msha-controller-operator-history
- **controller_controls_operator:** Marshal  Renfro → Renfro Sand & Concrete Company; 1950-01-01 to 1993-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Renfro Sand & Concrete Company → Renfro; 1994-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sam M  Renfro → Renfro; 1994-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sam M  Renfro → Renfro Sand & Concrete Company; 1994-01-01 to current/open; source msha-controller-operator-history