# Relationship history for MSHA mine 0503519

Current hierarchy: **Kellogg Coal Corp & Coal Fuels Corp → K C F Associates → K-400**

- 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:** K C F Associates → K-400; 1980-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Kellogg Coal Corp & Coal Fuels Corp → K-400; 1980-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kellogg Coal Corp & Coal Fuels Corp → K C F Associates; 1980-01-01 to current/open; source msha-controller-operator-history