# Relationship history for MSHA mine 3606640

Current hierarchy: **Mikel Edward → Mikel Coal Company → Highland Ii**

- 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

- **controller_controls_mine:** Mikel Edward → Highland Ii; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Richard Coal → Highland Ii; 1978-04-01 to 1987-01-30; source msha-controller-operator-history
- **controller_controls_mine:** Patrick Richard → Highland Ii; 1978-04-01 to 1987-01-30; source msha-controller-operator-history
- **controller_controls_operator:** Patrick Richard → Richard Coal; 1978-04-01 to 1987-01-30; source msha-controller-operator-history
- **operator_operates_mine:** Mikel Coal Company → Highland Ii; 1987-01-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mikel Edward → Mikel Coal Company; 1987-01-31 to current/open; source msha-controller-operator-history