# Relationship history for MSHA mine 1512488

Current hierarchy: **Crawford Lawrence → D & D Coal Company → No 1 Mine D & D Coal Co**

- 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:** D & D Coal Company → No 1 Mine D & D Coal Co; 1980-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Crawford Lawrence → No 1 Mine D & D Coal Co; 1980-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Crawford Lawrence → D & D Coal Company; 1980-01-01 to current/open; source msha-controller-operator-history