# Relationship history for MSHA mine 2101670

Current hierarchy: **Anderson Ron → Ancon Inc → Scandia 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

- **operator_operates_mine:** Barton Contracting Company → Scandia Pit; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Eugene  Barton → Scandia Pit; 1950-01-01 to 1983-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Eugene  Barton → Barton Contracting Company; 1950-01-01 to 1978-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Ancon Inc → Scandia Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Anderson Ron → Scandia Pit; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Anderson Ron → Ancon Inc; 1979-01-01 to current/open; source msha-controller-operator-history