# Relationship history for MSHA mine 2103871

Current hierarchy: **Knife River Corporation → Knife River Materials → Crusher #43526**

- 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 → Crusher #43526; 2002-03-14 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Knife River Materials → Crusher #43526; 2016-02-08 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Knife River Materials; 2016-02-08 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Crusher #43526; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Knife River Materials; 2023-06-01 to current/open; source msha-controller-operator-history