# Relationship history for MSHA mine 4200161

Current hierarchy: **Koch Industries Inc → Georgia-Pacific Gypsum LLC → Sigurd Quarries**

- 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:** G-P Gypsum Corp → Sigurd Quarries; 1950-01-01 to 2007-06-20; source msha-controller-operator-history
- **controller_controls_mine:** Georgia Pacific Corp → Sigurd Quarries; 1950-01-01 to 2005-12-22; source msha-controller-operator-history
- **controller_controls_operator:** Georgia Pacific Corp → G-P Gypsum Corp; 1950-01-01 to 2005-12-22; source msha-controller-operator-history
- **controller_controls_mine:** Koch Industries Inc → Sigurd Quarries; 2005-12-23 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Koch Industries Inc → G-P Gypsum Corp; 2005-12-23 to 2007-06-20; source msha-controller-operator-history
- **controller_controls_mine:** Koch Industries Inc → Sigurd Quarries; 2006-12-31 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Georgia-Pacific Gypsum LLC → Sigurd Quarries; 2007-06-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Koch Industries Inc → Georgia-Pacific Gypsum LLC; 2007-06-21 to current/open; source msha-controller-operator-history