# Relationship history for MSHA mine 3003613

Current hierarchy: **Joseph T  Ferdula → Ferdula Gravel Products Inc → Portable Seco 6x16 Screen**

- 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

- **controller_controls_mine:** Joseph T  Ferdula → Portable Seco 6x16 Screen; 1980-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ferdula Gravel Products Inc → Portable Seco 6x16 Screen; 2007-10-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joseph T  Ferdula → Ferdula Gravel Products Inc; 2007-10-23 to current/open; source msha-controller-operator-history