# Relationship history for MSHA mine 2402142

Current hierarchy: **MDU Resources Group Inc → Plains Ready Mix Concrete → PLAINS WASH PLANT**

- 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:** Plains Ready Mix Concrete → PLAINS WASH PLANT; 1998-06-01 to 2000-05-09; source msha-controller-operator-history
- **controller_controls_mine:** Frank A  Thomas  et al → PLAINS WASH PLANT; 1998-06-01 to 2000-05-09; source msha-controller-operator-history
- **controller_controls_operator:** Frank A  Thomas  et al → Plains Ready Mix Concrete; 1998-06-01 to 2000-05-09; source msha-controller-operator-history
- **operator_operates_mine:** Plains Ready Mix Concrete → PLAINS WASH PLANT; 2000-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → PLAINS WASH PLANT; 2000-05-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Plains Ready Mix Concrete; 2000-05-10 to current/open; source msha-controller-operator-history