# Relationship history for MSHA mine 4606187

Current hierarchy: **Skaggs Edward O & Jerry P Frisby → Canion Coal Inc → Leatherwood #4**

- 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:** Canion Coal Inc → Leatherwood #4; 1980-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Skaggs Edward O & Jerry P Frisby → Leatherwood #4; 1980-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Skaggs Edward O & Jerry P Frisby → Canion Coal Inc; 1980-07-01 to current/open; source msha-controller-operator-history