# Relationship history for MSHA mine 3303700

Current hierarchy: **Petrozzi Tillio P → Eastern Ohio Coal Co Inc → Cambridge Strip**

- 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

- **controller_controls_mine:** Petrozzi Tillio P → Cambridge Strip; 1975-02-14 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Eastern Ohio Coal Co Inc → Cambridge Strip; 1978-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Petrozzi Tillio P → Eastern Ohio Coal Co Inc; 1978-08-01 to current/open; source msha-controller-operator-history