# Relationship history for MSHA mine 3608276

Current hierarchy: **Northern Star Generation Services Co LLC → Cambria CoGen Company → Cambria Cogen Facility**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Air Products & Chemicals Inc → Cambria Cogen Facility; 1991-09-01 to 2001-08-23; source msha-controller-operator-history
- **controller_controls_mine:** Air Products & Chemicals Inc → Cambria Cogen Facility; 1991-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Air Products & Chemicals Inc → Air Products & Chemicals Inc; 1991-09-01 to 2001-08-23; source msha-controller-operator-history
- **operator_operates_mine:** Cambria Cogen (I), L.L.C. → Cambria Cogen Facility; 2001-08-24 to 2004-12-14; source msha-controller-operator-history
- **controller_controls_mine:** El Paso Energy Corp → Cambria Cogen Facility; 2001-08-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** El Paso Energy Corp → Cambria Cogen (I), L.L.C.; 2001-08-24 to 2004-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Cambria CoGen Company → Cambria Cogen Facility; 2004-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Northern Star Generation Services Co LLC → Cambria Cogen Facility; 2004-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Northern Star Generation Services Co LLC → Cambria CoGen Company; 2004-12-15 to current/open; source msha-controller-operator-history