# Relationship history for MSHA mine 0600821

Current hierarchy: **Arnold M  Karp → Rockhead LLC → Terex 1800 Warrior Screener**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Arnold M  Karp → Terex 1800 Warrior Screener; 2019-05-10 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Rockhead LLC → Terex 1800 Warrior Screener; 2020-08-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Arnold M  Karp → Rockhead LLC; 2020-08-26 to current/open; source msha-controller-operator-history