# Relationship history for MSHA mine 3609871

Current hierarchy: **David R  Vangorder → Vangorder Stone → Groover No. 2**

- 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:** Vangorder Stone → Groover No. 2; 2010-08-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** David R  Vangorder → Groover No. 2; 2010-08-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David R  Vangorder → Vangorder Stone; 2010-08-11 to current/open; source msha-controller-operator-history