# Relationship history for MSHA mine 0900904

Current hierarchy: **Bob  Stevens → Georgia-Carolina Quarries Inc → GEORGIA-CAROLINA QUARRY**

- 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:** Georgia-Carolina Quarries Inc → GEORGIA-CAROLINA QUARRY; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Bob  Stevens → GEORGIA-CAROLINA QUARRY; 1979-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bob  Stevens → Georgia-Carolina Quarries Inc; 1979-01-01 to current/open; source msha-controller-operator-history