# Relationship history for MSHA mine 3607750

Current hierarchy: **Carl  Carbonara; Donna C  Chico → Dearth Coal Company → Dearth 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:** Dearth Coal Company → Dearth Mine; 1985-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Donna C  Chico et al → Dearth Mine; 1985-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Donna C  Chico et al → Dearth Coal Company; 1985-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Carl  Carbonara et al → Dearth Coal Company; 1985-10-01 to current/open; source msha-controller-operator-history