# Relationship history for MSHA mine 0502781

Current hierarchy: **Atlantic Richfield Company → Atlantic Richfield Company → Sylvester Gulch Test Audit**

- 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:** Atlantic Richfield Company → Sylvester Gulch Test Audit; 1975-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Atlantic Richfield Company → Sylvester Gulch Test Audit; 1975-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Atlantic Richfield Company → Atlantic Richfield Company; 1975-12-01 to current/open; source msha-controller-operator-history