# Relationship history for MSHA mine 4105820

Current hierarchy: **William  Penz; Barry  Rich → North Texas Natural Select Materials → Combine Pit**

- 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:** William  Penz et al → Combine Pit; 2022-10-25 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** North Texas Natural Select Materials → Combine Pit; 2025-10-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** William  Penz et al → North Texas Natural Select Materials; 2025-10-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barry  Rich et al → North Texas Natural Select Materials; 2025-10-07 to current/open; source msha-controller-operator-history