# Relationship history for MSHA mine 1512117

Current hierarchy: **Swanton Corp → Kenerco Corp → No 1 Surface**

- 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:** Kenerco Corp → No 1 Surface; 1979-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Swanton Corp → No 1 Surface; 1979-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Swanton Corp → Kenerco Corp; 1979-11-01 to current/open; source msha-controller-operator-history