# Relationship history for MSHA mine 4702770

Current hierarchy: **Mathy Construction Company → Arthur Overgaard Division → Barron County Saffer 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Adolph T Schwartz → Barron County Saffer Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Arthur Overgaard Inc → Barron County Saffer Pit; 1984-07-01 to 1984-07-16; source msha-controller-operator-history
- **controller_controls_operator:** Adolph T Schwartz → Arthur Overgaard Inc; 1984-07-01 to 1984-07-16; source msha-controller-operator-history
- **operator_operates_mine:** Arthur Overgaard Division → Barron County Saffer Pit; 1984-07-17 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mathy Construction Company → Barron County Saffer Pit; 1984-07-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mathy Construction Company → Arthur Overgaard Division; 1984-07-17 to current/open; source msha-controller-operator-history