# Relationship history for MSHA mine 1511817

Current hierarchy: **Stigler Dave & Ray Emmons → E & V Contractors → E & V Contractors (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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** E & V Contractors → E & V Contractors (Surface); 1979-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Stigler Dave & Ray Emmons Et Al → E & V Contractors (Surface); 1979-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stigler Dave & Ray Emmons Et Al → E & V Contractors; 1979-03-01 to current/open; source msha-controller-operator-history