# Relationship history for MSHA mine 1901317

Current hierarchy: **Ryan  Vlaco → Ryco excavating inc → SCR-14 sandvik**

- 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:** ryco excavating inc → SCR-14 sandvik; 2023-05-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ryan  Vlaco → SCR-14 sandvik; 2023-05-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ryan  Vlaco → ryco excavating inc; 2023-05-08 to current/open; source msha-controller-operator-history