# Relationship history for MSHA mine 1511073

Current hierarchy: **Babb John A → John A Babb Land Improvement → Babb 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** John A Babb Land Improvement → Babb Strip; 1978-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Babb John A → Babb Strip; 1978-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Babb John A → John A Babb Land Improvement; 1978-03-01 to current/open; source msha-controller-operator-history