# Relationship history for MSHA mine 4503502

Current hierarchy: **Darryl G Becker → NW  Construction General Contracting Incorporated → Extec 1**

- 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:** NW  Construction General Contracting Incorporated → Extec 1; 2001-10-25 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Darryl G Becker → Extec 1; 2001-10-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Darryl G Becker → NW  Construction General Contracting Incorporated; 2001-10-25 to current/open; source msha-controller-operator-history