# Relationship history for MSHA mine 0101570

Current hierarchy: **Helfrich George → Century Mine Management Company Inc → Century Coal Strip No 1**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Century Mine Management Company Inc → Century Coal Strip No 1; 1976-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Helfrich George → Century Coal Strip No 1; 1976-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Helfrich George → Century Mine Management Company Inc; 1976-10-01 to current/open; source msha-controller-operator-history