# Relationship history for MSHA mine 2400486

Current hierarchy: **Knife River Corporation → JTL Group Incorporated → MRM WASH PLANT #170**

- 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:** Monroc Inc → MRM WASH PLANT #170; 1950-01-01 to 1987-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Wel-Com Financial Services & M-K Holding Corp → MRM WASH PLANT #170; 1950-01-01 to 2000-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Wel-Com Financial Services & M-K Holding Corp → Monroc Inc; 1950-01-01 to 1987-09-14; source msha-controller-operator-history
- **controller_controls_mine:** Frank A  Thomas  et al → MRM WASH PLANT #170; 1984-05-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** U S Aggregate Inc → MRM WASH PLANT #170; 1986-06-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Monroc Inc → MRM WASH PLANT #170; 1987-09-15 to 1993-05-24; source msha-controller-operator-history
- **controller_controls_operator:** U S Aggregate Inc → Monroc Inc; 1987-09-15 to 1993-05-24; source msha-controller-operator-history
- **operator_operates_mine:** Polson Ready Mix Concrete Inc → MRM WASH PLANT #170; 1993-05-25 to 2000-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Frank A  Thomas  et al → Polson Ready Mix Concrete Inc; 1993-05-25 to 2000-09-30; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → MRM WASH PLANT #170; 1999-09-01 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Polson Ready Mix Concrete Inc → MRM WASH PLANT #170; 2000-10-01 to 2001-12-31; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → MRM WASH PLANT #170; 2000-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Polson Ready Mix Concrete Inc; 2000-10-01 to 2001-12-31; source msha-controller-operator-history
- **operator_operates_mine:** JTL Group Incorporated → MRM WASH PLANT #170; 2002-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → JTL Group Incorporated; 2002-01-01 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → MRM WASH PLANT #170; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → JTL Group Incorporated; 2023-06-01 to current/open; source msha-controller-operator-history