# Relationship history for MSHA mine 4101302

Current hierarchy: **Ideal Basic Industries Inc → Thorstenberg Materials Company Inc → Helms Sand And Gravel Pit And Mill**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **operator_operates_mine:** Thorstenberg Materials Company Inc → Helms Sand And Gravel Pit And Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Ideal Basic Industries Inc → Helms Sand And Gravel Pit And Mill; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ideal Basic Industries Inc → Thorstenberg Materials Company Inc; 1950-01-01 to current/open; source msha-controller-operator-history