# Relationship history for MSHA mine 2500932

Current hierarchy: **Van Kirk John → Van Kirk Sand & Gravel Inc → Van Kirk Sand & Gravel**

- 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:** Van Kirk Sand & Gravel Inc → Van Kirk Sand & Gravel; 1979-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Van Kirk John → Van Kirk Sand & Gravel; 1979-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Van Kirk John → Van Kirk Sand & Gravel Inc; 1979-05-01 to current/open; source msha-controller-operator-history