# Relationship history for MSHA mine 4503296

Current hierarchy: **Opsahl A Craig → Craig Opsahl Rock & Construction → Opsahl Pit & Plant**

- 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:** Craig Opsahl Rock & Construction → Opsahl Pit & Plant; 1993-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Opsahl A Craig → Opsahl Pit & Plant; 1993-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Opsahl A Craig → Craig Opsahl Rock & Construction; 1993-05-01 to current/open; source msha-controller-operator-history