# Relationship history for MSHA mine 1510987

Current hierarchy: **Cobb Alfred → Cobb Coal Company Inc → No 8**

- 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:** Cobb Coal Company Inc → No 8; 1977-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cobb Alfred Et Al → No 8; 1977-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cobb Alfred Et Al → Cobb Coal Company Inc; 1977-12-01 to current/open; source msha-controller-operator-history