# Relationship history for MSHA mine 2001331

Current hierarchy: **Virginia Franke  Salisbury → Higher Ground Aggregates → FRANKE PIT 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:** Franke Septic Tank Service → FRANKE PIT 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Virginia Franke  Salisbury → FRANKE PIT 1; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Virginia Franke  Salisbury → Franke Septic Tank Service; 1950-01-01 to current/open; source msha-controller-operator-history