# Relationship history for MSHA mine 4300528

Current hierarchy: **Heath H  Wright → WRIGHT'S EXCAVATING → BERKSHIRE SAND & GRAVEL**

- 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:** Wright's Excavating → BERKSHIRE SAND & GRAVEL; 1999-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Roger H  Wright → BERKSHIRE SAND & GRAVEL; 1999-07-01 to 2023-01-12; source msha-controller-operator-history
- **controller_controls_operator:** Roger H  Wright → Wright's Excavating; 1999-07-01 to 2023-01-12; source msha-controller-operator-history
- **controller_controls_mine:** Heath H  Wright → BERKSHIRE SAND & GRAVEL; 2023-01-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heath H  Wright → Wright's Excavating; 2023-01-13 to current/open; source msha-controller-operator-history