# Relationship history for MSHA mine 2002980

Current hierarchy: **Luke  Rohloff → Rohloff Sand & Gravel Company → ROHLOFF SAND & GRAVEL CO.**

- 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:** Rohloff Sand & Gravel Company → ROHLOFF SAND & GRAVEL CO.; 1996-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Luke  Rohloff → ROHLOFF SAND & GRAVEL CO.; 1996-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Luke  Rohloff → Rohloff Sand & Gravel Company; 1996-06-01 to current/open; source msha-controller-operator-history