# Relationship history for MSHA mine 1517847

Current hierarchy: **Middleton Mary Lynn → Bic Coal Company Inc → Bic No 2**

- 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

- **controller_controls_mine:** Middleton Mary Lynn Et Al → Bic No 2; 1987-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Bic Coal Company Inc → Bic No 2; 1996-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Middleton Mary Lynn Et Al → Bic Coal Company Inc; 1996-09-01 to current/open; source msha-controller-operator-history