# Relationship history for MSHA mine 1518842

Current hierarchy: **Edsel H  Preece → Twin Energy, L. L. C. → Sandlick No. 1 Surface**

- 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

- **operator_operates_mine:** Twin Energy, L. L. C. → Sandlick No. 1 Surface; 2005-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Edsel H  Preece et al → Sandlick No. 1 Surface; 2005-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edsel H  Preece et al → Twin Energy, L. L. C.; 2005-01-31 to current/open; source msha-controller-operator-history