# Relationship history for MSHA mine 4002821

Current hierarchy: **Hatmaker Charles → A A Coal Company → 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:** A A Coal Company → Surface; 1983-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hatmaker Charles → Surface; 1983-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hatmaker Charles → A A Coal Company; 1983-01-01 to current/open; source msha-controller-operator-history