# Relationship history for MSHA mine 3200966

Current hierarchy: **Knife River Corporation → Knife River Corporation - NC Division → Portable Plant #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:** Bauerly Brothers Inc → Portable Plant #2; 1950-01-01 to 2001-04-25; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → Portable Plant #2; 2001-04-26 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Knife River Corporation - NC Division → Portable Plant #2; 2012-05-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bauerly Brothers Inc → Knife River Corporation - NC Division; 2012-05-17 to 2001-04-25; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Knife River Corporation - NC Division; 2012-05-17 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Portable Plant #2; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Knife River Corporation - NC Division; 2023-06-01 to current/open; source msha-controller-operator-history