# Relationship history for MSHA mine 2700421

Current hierarchy: **Gregg F.  Saunders → GFS Corp. General Contracting Services → Portable**

- 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:** GFS Corp. General Contracting Services → Portable; 2007-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gregg F.  Saunders → Portable; 2007-05-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregg F.  Saunders → GFS Corp. General Contracting Services; 2007-05-24 to current/open; source msha-controller-operator-history