# Relationship history for MSHA mine 0100819

Current hierarchy: **Hughes J D → A & J Coal Co → A And J Strip Mine**

- 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:** A & J Coal Co → A And J Strip Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hughes J D → A And J Strip Mine; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hughes J D → A & J Coal Co; 1950-01-01 to current/open; source msha-controller-operator-history