# Relationship history for MSHA mine 0503919

Current hierarchy: **Estate of Henry T. Southway Jr. → Southway Construction Company Inc → Portable Crushing Plant No 2**

- 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:** Estate of Henry T. Southway Jr. → Portable Crushing Plant No 2; 1982-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southway Construction Company Inc → Portable Crushing Plant No 2; 1983-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Estate of Henry T. Southway Jr. → Southway Construction Company Inc; 1983-11-01 to current/open; source msha-controller-operator-history