# Relationship history for MSHA mine 2402580

Current hierarchy: **Concord Energy Holdings LLC → Concord Field Services, LLC → Portable #2**

- 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

- **controller_controls_mine:** Trenton  Stafford et al → Portable #2; 2010-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Seifert Enterprises, LLC → Portable #2; 2011-04-13 to 2012-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Trenton  Stafford et al → Seifert Enterprises, LLC; 2011-04-13 to 2012-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Kent  Beach et al → Seifert Enterprises, LLC; 2011-04-13 to 2012-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Concord Energy Holdings LLC → Portable #2; 2011-06-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Concord Field Services, LLC → Portable #2; 2012-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Concord Energy Holdings LLC → Concord Field Services, LLC; 2012-06-01 to current/open; source msha-controller-operator-history