# Relationship history for MSHA mine 0600626

Current hierarchy: **Smallwood William → Midwood Quarry & Construction Inc → Burgundy Hill 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Midwood Quarry & Construction Inc → Burgundy Hill Quarry; 1989-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Smallwood William → Burgundy Hill Quarry; 1989-03-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Smallwood William → Midwood Quarry & Construction Inc; 1989-03-01 to current/open; source msha-controller-operator-history