# Relationship history for MSHA mine 0202183

Current hierarchy: **Diffie Arbie B → A R D Construction & Mining Inc → Philadelphia**

- 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 R D Construction & Mining Inc → Philadelphia; 1983-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Diffie Arbie B → Philadelphia; 1983-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Diffie Arbie B → A R D Construction & Mining Inc; 1983-09-01 to current/open; source msha-controller-operator-history