# Relationship history for MSHA mine 0201008

Current hierarchy: **Nord Resources Corp → Nord Sil-Flo (Nord Perlite) → Nord Sil Flo (Nord Perlite)**

- 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:** Filters International Inc → Nord Sil Flo (Nord Perlite); 1950-01-01 to 1982-12-20; source msha-controller-operator-history
- **controller_controls_mine:** Korhumel L A → Nord Sil Flo (Nord Perlite); 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Korhumel L A → Filters International Inc; 1950-01-01 to 1982-12-20; source msha-controller-operator-history
- **operator_operates_mine:** Sil-Flo Inc → Nord Sil Flo (Nord Perlite); 1982-12-21 to 1986-10-27; source msha-controller-operator-history
- **controller_controls_mine:** Oeters J Charles → Nord Sil Flo (Nord Perlite); 1982-12-21 to 1986-10-27; source msha-controller-operator-history
- **controller_controls_operator:** Oeters J Charles → Sil-Flo Inc; 1982-12-21 to 1986-10-27; source msha-controller-operator-history
- **operator_operates_mine:** Nord Sil-Flo (Nord Perlite) → Nord Sil Flo (Nord Perlite); 1986-10-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Nord Resources Corp → Nord Sil Flo (Nord Perlite); 1986-10-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Nord Resources Corp → Nord Sil-Flo (Nord Perlite); 1986-10-28 to current/open; source msha-controller-operator-history