# Relationship history for MSHA mine 1900609

Current hierarchy: **Sansone Francis J & Robert C → Sansone Brothers → Sharon Loam Plant**

- 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:** Sansone Brothers → Sharon Loam Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Sansone Francis J & Robert C → Sharon Loam Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Sansone Francis J & Robert C → Sansone Brothers; 1950-01-01 to current/open; source msha-controller-operator-history