# Relationship history for MSHA mine 1516278

Current hierarchy: **Marshall Afton → M B & S Coal Augering Company Inc → Auger #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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** M B & S Coal Augering Company Inc → Auger #2; 1988-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Marshall Afton Et Al → Auger #2; 1988-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Marshall Afton Et Al → M B & S Coal Augering Company Inc; 1988-01-01 to current/open; source msha-controller-operator-history