# Relationship history for MSHA mine 3300075

Current hierarchy: **O E  Hamilton → J M Hamilton & Sons Company → J. M. HAMILTON & SONS COMPANY**

- 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:** J M Hamilton & Sons Company → J. M. HAMILTON & SONS COMPANY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** O E  Hamilton → J. M. HAMILTON & SONS COMPANY; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** O E  Hamilton → J M Hamilton & Sons Company; 1950-01-01 to current/open; source msha-controller-operator-history