# Relationship history for MSHA mine 0401961

Current hierarchy: **John W  Hertzig → John W Hertzig → JOHN W. HERTZIG**

- 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:** Sport Hill Sand & Gravel → JOHN W. HERTZIG; 1950-01-01 to 1993-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Alfred E  Fisher → JOHN W. HERTZIG; 1950-01-01 to 1993-04-30; source msha-controller-operator-history
- **controller_controls_operator:** Alfred E  Fisher → Sport Hill Sand & Gravel; 1950-01-01 to 1993-04-30; source msha-controller-operator-history
- **operator_operates_mine:** John W Hertzig → JOHN W. HERTZIG; 1993-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** John W  Hertzig → JOHN W. HERTZIG; 1993-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** John W  Hertzig → John W Hertzig; 1993-05-01 to current/open; source msha-controller-operator-history