# Relationship history for MSHA mine 3200764

Current hierarchy: **Fred  Schock → Schock Dozer Service → SCHOCK 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:** Schock Dozer Service → SCHOCK PIT; 1998-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Fred  Schock → SCHOCK PIT; 1998-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Fred  Schock → Schock Dozer Service; 1998-07-01 to current/open; source msha-controller-operator-history