# Relationship history for MSHA mine 3610491

Current hierarchy: **Zac  Barbato → Keystone Crushing LLC → Kleemann MC110**

- 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:** Zac  Barbato  et al → Kleemann MC110; 2025-02-16 to 2025-11-29; source msha-controller-operator-history
- **controller_controls_mine:** Zac  Barbato → Kleemann MC110; 2025-11-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Keystone Crushing LLC → Kleemann MC110; 2026-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Zac  Barbato  et al → Keystone Crushing LLC; 2026-02-27 to 2025-11-29; source msha-controller-operator-history
- **controller_controls_operator:** Jeff  Pierson et al → Keystone Crushing LLC; 2026-02-27 to 2025-11-29; source msha-controller-operator-history
- **controller_controls_operator:** Zac  Barbato → Keystone Crushing LLC; 2026-02-27 to current/open; source msha-controller-operator-history