# Relationship history for MSHA mine 4602838

Current hierarchy: **Harrold Don → Joyce Properties Inc → Helmick No 1 Mine (Surface)**

- 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:** Joyce Properties Inc → Helmick No 1 Mine (Surface); 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Harrold Don → Helmick No 1 Mine (Surface); 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Harrold Don → Joyce Properties Inc; 1950-01-01 to current/open; source msha-controller-operator-history