# Relationship history for MSHA mine 3606353

Current hierarchy: **Richards Kenneth G → Richards Coal Company → Richards Coal Company**

- 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:** Richards Coal Company → Richards Coal Company; 1977-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richards Kenneth G → Richards Coal Company; 1977-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richards Kenneth G → Richards Coal Company; 1977-05-01 to current/open; source msha-controller-operator-history