# Relationship history for MSHA mine 4801920

Current hierarchy: **Nellie  Searle → Searle Brothers Construction Co. → 2005 Metso Lokotrack LT 1213 Impact Crus**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Nellie  Searle et al → 2005 Metso Lokotrack LT 1213 Impact Crus; 1988-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Searle Brothers Construction Co. → 2005 Metso Lokotrack LT 1213 Impact Crus; 2026-06-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nellie  Searle et al → Searle Brothers Construction Co.; 2026-06-04 to current/open; source msha-controller-operator-history