# Relationship history for MSHA mine 3607657

Current hierarchy: **Sobotka Ruth Ellen → Black Carbon Fuels Inc → Toth 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:** Black Carbon Fuels Inc → Toth Mine; 1985-01-01 to 1985-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Petracca Barbara → Toth Mine; 1985-01-01 to 1985-04-23; source msha-controller-operator-history
- **controller_controls_operator:** Petracca Barbara → Black Carbon Fuels Inc; 1985-01-01 to 1985-04-23; source msha-controller-operator-history
- **operator_operates_mine:** Black Carbon Fuels Inc → Toth Mine; 1985-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sobotka Ruth Ellen → Toth Mine; 1985-04-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sobotka Ruth Ellen → Black Carbon Fuels Inc; 1985-04-24 to current/open; source msha-controller-operator-history