# Relationship history for MSHA mine 2500941

Current hierarchy: **Duane  Kroeger → Kroeger Sand & Gravel → KROEGER SAND & GRAVEL PIT**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Kroeger Sand & Gravel → KROEGER SAND & GRAVEL PIT; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Duane  Kroeger → KROEGER SAND & GRAVEL PIT; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Duane  Kroeger → Kroeger Sand & Gravel; 1979-01-01 to current/open; source msha-controller-operator-history