# Relationship history for MSHA mine 4501745

Current hierarchy: **Gilbertson Ron & Lori → E V Q Company → Enterprise Valley Quarry**

- 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:** Unlimited Enterprises Inc → Enterprise Valley Quarry; 1950-01-01 to 1983-04-12; source msha-controller-operator-history
- **controller_controls_mine:** Robin L  Hauge → Enterprise Valley Quarry; 1950-01-01 to 1983-04-12; source msha-controller-operator-history
- **controller_controls_operator:** Robin L  Hauge → Unlimited Enterprises Inc; 1950-01-01 to 1983-04-12; source msha-controller-operator-history
- **operator_operates_mine:** E V Q Company → Enterprise Valley Quarry; 1983-04-13 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gilbertson Ron & Lori → Enterprise Valley Quarry; 1983-04-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gilbertson Ron & Lori → E V Q Company; 1983-04-13 to current/open; source msha-controller-operator-history