# Relationship history for MSHA mine 0202951

Current hierarchy: **International Separation Systems Ltd → International Separation Systems Arizona, Inc. → ISSI Arizona Inc**

- 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:** International Separation Systems Arizona, Inc. → ISSI Arizona Inc; 2001-10-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** International Separation Systems Ltd → ISSI Arizona Inc; 2001-10-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** International Separation Systems Ltd → International Separation Systems Arizona, Inc.; 2001-10-15 to current/open; source msha-controller-operator-history