# Relationship history for MSHA mine 2100662

Current hierarchy: **Swartout Ed → Ed Swartout Inc → Nicollet County Pit**

- 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:** Swartout Ed → Nicollet County Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** R W Zimmerman Trucking → Nicollet County Pit; 1950-01-01 to 1979-10-11; source msha-controller-operator-history
- **controller_controls_mine:** Zimmerman R W Trucking → Nicollet County Pit; 1950-01-01 to 1979-10-11; source msha-controller-operator-history
- **controller_controls_operator:** Zimmerman R W Trucking → R W Zimmerman Trucking; 1950-01-01 to 1979-10-11; source msha-controller-operator-history
- **operator_operates_mine:** Ed Swartout Inc → Nicollet County Pit; 1979-10-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Swartout Ed → Ed Swartout Inc; 1979-10-12 to current/open; source msha-controller-operator-history