# Relationship history for MSHA mine 3604624

Current hierarchy: **Polenik John → Blough Coal Company Inc → Bell 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

- **operator_operates_mine:** Portage Slag & Cinder Inc → Bell Strip; 1950-01-01 to 1974-02-01; source msha-controller-operator-history
- **controller_controls_mine:** Bellvia Rose → Bell Strip; 1950-01-01 to 1974-02-01; source msha-controller-operator-history
- **controller_controls_operator:** Bellvia Rose → Portage Slag & Cinder Inc; 1950-01-01 to 1974-02-01; source msha-controller-operator-history
- **operator_operates_mine:** Blough Coal Company Inc → Bell Strip; 1974-02-02 to 1974-06-10; source msha-controller-operator-history
- **controller_controls_mine:** Coleman Ronald → Bell Strip; 1974-02-02 to 1974-06-10; source msha-controller-operator-history
- **controller_controls_operator:** Coleman Ronald → Blough Coal Company Inc; 1974-02-02 to 1974-06-10; source msha-controller-operator-history
- **operator_operates_mine:** Blough Coal Company Inc → Bell Strip; 1974-06-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Polenik John → Bell Strip; 1974-06-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Polenik John → Blough Coal Company Inc; 1974-06-11 to current/open; source msha-controller-operator-history