# Relationship history for MSHA mine 1515004

Current hierarchy: **Borders Earl D → Borders Excavating Inc → No 2 Surface (D)**

- 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:** Borders Excavating Inc → No 2 Surface (D); 1984-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Borders Earl D → No 2 Surface (D); 1984-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Borders Earl D → Borders Excavating Inc; 1984-11-01 to current/open; source msha-controller-operator-history