# Relationship history for MSHA mine 1519250

Current hierarchy: **Edsel H  Preece → Twin Ridge Development Inc. → ICG No. 1**

- 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

- **controller_controls_mine:** Edsel H  Preece et al → ICG No. 1; 2004-07-22 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Twin Ridge Development Inc. → ICG No. 1; 2008-06-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Edsel H  Preece et al → Twin Ridge Development Inc.; 2008-06-18 to current/open; source msha-controller-operator-history