# Relationship history for MSHA mine 1508433

Current hierarchy: **Balena Joseph → Airco Mining Company Corp → No 1 Mine**

- 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:** S H & W Coals Inc → No 1 Mine; 1975-06-01 to 1981-04-12; source msha-controller-operator-history
- **controller_controls_mine:** Smith Sam B → No 1 Mine; 1975-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smith Sam B → S H & W Coals Inc; 1975-06-01 to 1981-04-12; source msha-controller-operator-history
- **operator_operates_mine:** Airco Mining Company Corp → No 1 Mine; 1981-04-13 to 1981-09-07; source msha-controller-operator-history
- **controller_controls_mine:** Kessler Jim → No 1 Mine; 1981-04-13 to 1981-09-07; source msha-controller-operator-history
- **controller_controls_operator:** Kessler Jim → Airco Mining Company Corp; 1981-04-13 to 1981-09-07; source msha-controller-operator-history
- **operator_operates_mine:** Airco Mining Company Corp → No 1 Mine; 1981-09-08 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Balena Joseph → No 1 Mine; 1981-09-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Balena Joseph → Airco Mining Company Corp; 1981-09-08 to current/open; source msha-controller-operator-history