# Relationship history for MSHA mine 0405286

Current hierarchy: **Bill  Hanmer → Hanmer Materials → Portable Plant #4**

- 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:** Bill  Hanmer → Portable Plant #4; 1990-12-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hanmer Materials → Portable Plant #4; 1996-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bill  Hanmer → Hanmer Materials; 1996-05-01 to current/open; source msha-controller-operator-history