# Relationship history for MSHA mine 5100241

Current hierarchy: **Knife River Corporation → West Hawaii Concrete → Portable-2**

- 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:** MDU Resources Group Inc → Portable-2; 2001-07-19 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** West Hawaii Concrete → Portable-2; 2002-05-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → West Hawaii Concrete; 2002-05-16 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Portable-2; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → West Hawaii Concrete; 2023-06-01 to current/open; source msha-controller-operator-history