# Relationship history for MSHA mine 1517193

Current hierarchy: **David A  Betscher → W C A Inc → No 2 Auger**

- 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:** David A  Betscher Et Al → No 2 Auger; 1979-10-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** W C A Inc → No 2 Auger; 1992-02-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David A  Betscher Et Al → W C A Inc; 1992-02-01 to current/open; source msha-controller-operator-history