# Relationship history for MSHA mine 4202291

Current hierarchy: **Gordon S  Ziegler Jr → Ziegler Chemical & Mineral Corp → HARDAWAY**

- 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:** Gordon S  Ziegler Jr → HARDAWAY; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Ziegler Chemical & Mineral Corp → HARDAWAY; 2000-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gordon S  Ziegler Jr → Ziegler Chemical & Mineral Corp; 2000-04-01 to current/open; source msha-controller-operator-history