# Relationship history for MSHA mine 3901517

Current hierarchy: **Kenny B  Opitz → Opitz Gravel → K & O**

- 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:** Opitz Gravel → K & O; 2007-07-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kenny B  Opitz → K & O; 2007-07-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kenny B  Opitz → Opitz Gravel; 2007-07-25 to current/open; source msha-controller-operator-history