# Relationship history for MSHA mine 0504723

Current hierarchy: **Sam  McCleneghan III → Rock Island Project → PORTABLE SCREEN**

- 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:** Rock Island Project → PORTABLE SCREEN; 2001-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sam  McCleneghan III et al → PORTABLE SCREEN; 2001-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sam  McCleneghan III et al → Rock Island Project; 2001-09-01 to current/open; source msha-controller-operator-history