# Relationship history for MSHA mine 1102949

Current hierarchy: **O'Leary Michael → O'Leary Sand & Gravel Inc → Marengo 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:** O'Leary Sand & Gravel Inc → Marengo Quarry; 1993-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** O'Leary Michael → Marengo Quarry; 1993-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** O'Leary Michael → O'Leary Sand & Gravel Inc; 1993-09-01 to current/open; source msha-controller-operator-history