# Relationship history for MSHA mine 4503370

Current hierarchy: **Balmelli Brian → Hard Rock Quarry → HARD ROCK QUARRY**

- 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

- **operator_operates_mine:** Hard Rock Quarry → HARD ROCK QUARRY; 1997-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Balmelli Brian → HARD ROCK QUARRY; 1997-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Balmelli Brian → Hard Rock Quarry; 1997-10-01 to current/open; source msha-controller-operator-history