# Relationship history for MSHA mine 3200389

Current hierarchy: **Steve  McCormick → Valley Contracting → Valley Contracting Yard**

- 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:** Davidson Gravel → Valley Contracting Yard; 1950-01-01 to 1981-08-04; source msha-controller-operator-history
- **controller_controls_mine:** Davidson Woodrow → Valley Contracting Yard; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Davidson Woodrow → Davidson Gravel; 1950-01-01 to 1981-08-04; source msha-controller-operator-history
- **operator_operates_mine:** Valley Contracting → Valley Contracting Yard; 1981-08-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Steve  McCormick → Valley Contracting Yard; 1981-08-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steve  McCormick → Valley Contracting; 1981-08-05 to current/open; source msha-controller-operator-history