# Relationship history for MSHA mine 2501192

Current hierarchy: **Leah  Kembel → Kembel Sand & Gravel → McGrew**

- 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

- **controller_controls_mine:** Leah  Kembel → McGrew; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Kembel Sand & Gravel → McGrew; 1999-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Leah  Kembel → Kembel Sand & Gravel; 1999-06-01 to current/open; source msha-controller-operator-history