# Relationship history for MSHA mine 1901325

Current hierarchy: **John C  Kelly → Rykor Concrete & Civil, Inc. → Sandvik QJ341_Sandvik QH331**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Rykor Concrete & Civil, Inc. → Sandvik QJ341_Sandvik QH331; 2025-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John C  Kelly → Sandvik QJ341_Sandvik QH331; 2025-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John C  Kelly → Rykor Concrete & Civil, Inc.; 2025-04-03 to current/open; source msha-controller-operator-history