# Relationship history for MSHA mine 4300493

Current hierarchy: **Stephen M  Chmielewski → TROY MINERALS INC → HOGBACK 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:** Troy Minerals Inc → HOGBACK QUARRY; 1995-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mike  Chmielewski → HOGBACK QUARRY; 1995-03-01 to 2025-06-29; source msha-controller-operator-history
- **controller_controls_operator:** Mike  Chmielewski → Troy Minerals Inc; 1995-03-01 to 2025-06-29; source msha-controller-operator-history
- **controller_controls_mine:** Stephen M  Chmielewski → HOGBACK QUARRY; 2025-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stephen M  Chmielewski → Troy Minerals Inc; 2025-06-30 to current/open; source msha-controller-operator-history