# Relationship history for MSHA mine 4300542

Current hierarchy: **Thomas W  Tucker → Hardrock Gravel LLC → Hard Rock Gravel LLC**

- 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:** Tomco Excavating Inc → Hard Rock Gravel LLC; 2000-08-01 to 2005-06-01; source msha-controller-operator-history
- **controller_controls_mine:** Thomas W  Tucker → Hard Rock Gravel LLC; 2000-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas W  Tucker → Tomco Excavating Inc; 2000-08-01 to 2005-06-01; source msha-controller-operator-history
- **operator_operates_mine:** Hardrock Gravel LLC → Hard Rock Gravel LLC; 2005-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thomas W  Tucker → Hard Rock Gravel LLC; 2005-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas W  Tucker → Hardrock Gravel LLC; 2005-06-02 to current/open; source msha-controller-operator-history