# Relationship history for MSHA mine 4202812

Current hierarchy: **John D  Hadfield → TM Crushing LLC → Portable Impactor**

- 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:** John D  Hadfield et al → Portable Impactor; 2005-03-04 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** TM Crushing LLC → Portable Impactor; 2026-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John D  Hadfield et al → TM Crushing LLC; 2026-06-30 to current/open; source msha-controller-operator-history