# Relationship history for MSHA mine 4503328

Current hierarchy: **Forler Steve → Steve Forler Trucking → Forler Portable Screens**

- 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

- **operator_operates_mine:** Steve Forler Trucking → Forler Portable Screens; 1994-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Forler Steve → Forler Portable Screens; 1994-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Forler Steve → Steve Forler Trucking; 1994-10-01 to current/open; source msha-controller-operator-history