# Relationship history for MSHA mine 1516458

Current hierarchy: **Karst Edward W → Karst Robbins Coal Company Inc → Mine No 8b**

- 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:** Karst Edward W → Mine No 8b; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Karst Robbins Coal Company Inc → Mine No 8b; 1988-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Karst Edward W → Karst Robbins Coal Company Inc; 1988-08-01 to current/open; source msha-controller-operator-history