# Relationship history for MSHA mine 1901264

Current hierarchy: **Ryan  Vlaco → Ryco Excavating Contractor Inc → SCR-15**

- 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:** Ryco Excavating Contractor Inc → SCR-15; 2017-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ryan  Vlaco → SCR-15; 2017-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ryan  Vlaco → Ryco Excavating Contractor Inc; 2017-02-28 to current/open; source msha-controller-operator-history