# Relationship history for MSHA mine 4602718

Current hierarchy: **Mc Donough Company → Ohio River Sand & Gravel → O V Crane No 1 And Ohio Valley 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Ohio River Sand & Gravel → O V Crane No 1 And Ohio Valley Yard; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Mc Donough Company → O V Crane No 1 And Ohio Valley Yard; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mc Donough Company → Ohio River Sand & Gravel; 1950-01-01 to current/open; source msha-controller-operator-history