# Relationship history for MSHA mine 3608520

Current hierarchy: **Northern Star Generation Services Co LLC → Cambria Reclamation Corporation → Cambria Reclamation Corporation**

- 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:** Cambria Reclamation Corporation → Cambria Reclamation Corporation; 1995-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Air Products & Chemicals Inc → Cambria Reclamation Corporation; 1995-08-01 to 2001-08-23; source msha-controller-operator-history
- **controller_controls_operator:** Air Products & Chemicals Inc → Cambria Reclamation Corporation; 1995-08-01 to 2001-08-23; source msha-controller-operator-history
- **controller_controls_mine:** El Paso Energy Corp → Cambria Reclamation Corporation; 2001-08-24 to 2004-12-14; source msha-controller-operator-history
- **controller_controls_operator:** El Paso Energy Corp → Cambria Reclamation Corporation; 2001-08-24 to 2004-12-14; source msha-controller-operator-history
- **controller_controls_mine:** Northern Star Generation Services Co LLC → Cambria Reclamation Corporation; 2004-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Northern Star Generation Services Co LLC → Cambria Reclamation Corporation; 2004-12-15 to current/open; source msha-controller-operator-history