# Relationship history for MSHA mine 2602540

Current hierarchy: **Esmeralda County-NV → Esmeralda County Road Dept → Gemfield Laydown Yard**

- 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:** Esmeralda County Road Dept → Gemfield Laydown Yard; 2004-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Esmeralda County-NV → Gemfield Laydown Yard; 2004-05-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Esmeralda County-NV → Esmeralda County Road Dept; 2004-05-18 to current/open; source msha-controller-operator-history