# Relationship history for MSHA mine 2501329

Current hierarchy: **Jacquelyn  Chipperfield; Calvin  Chipperfield → McCook Concrete Inc → Perry 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

- **operator_operates_mine:** McCook Concrete Inc → Perry Pit; 2025-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jacquelyn  Chipperfield et al → Perry Pit; 2025-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jacquelyn  Chipperfield et al → McCook Concrete Inc; 2025-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Calvin  Chipperfield et al → McCook Concrete Inc; 2025-02-13 to current/open; source msha-controller-operator-history