# Relationship history for MSHA mine 3303947

Current hierarchy: **James F  Graham → Avis Coal Company → Hewett Fork**

- 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:** Avis Coal Company → Hewett Fork; 1983-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James F  Graham → Hewett Fork; 1983-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James F  Graham → Avis Coal Company; 1983-07-01 to current/open; source msha-controller-operator-history