# Relationship history for MSHA mine 2402326

Current hierarchy: **Knife River Corporation → JTL Group, Inc. Missoula → Portable Screen**

- 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 Screen; 1999-09-01 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** JTL Group, Inc. Missoula → Portable Screen; 2003-04-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → JTL Group, Inc. Missoula; 2003-04-04 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Portable Screen; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → JTL Group, Inc. Missoula; 2023-06-01 to current/open; source msha-controller-operator-history