# Relationship history for MSHA mine 0504425

Current hierarchy: **Beavers Mary → V & V Construction Company → Portable Plant #1**

- 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

- **controller_controls_mine:** Beavers Mary → Portable Plant #1; 1985-05-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** V & V Construction Company → Portable Plant #1; 1990-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Beavers Mary → V & V Construction Company; 1990-04-01 to current/open; source msha-controller-operator-history