# Relationship history for MSHA mine 4801597

Current hierarchy: **Knife River Corporation → JTL GROUP,INC. → Crusher #6**

- 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:** Ron  McMurry  et al → Crusher #6; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → Crusher #6; 1999-09-01 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Rissler & McMurry Co → Crusher #6; 2001-10-16 to 2010-06-13; source msha-controller-operator-history
- **controller_controls_operator:** Ron  McMurry  et al → Rissler & McMurry Co; 2001-10-16 to 2010-06-13; source msha-controller-operator-history
- **controller_controls_mine:** Ron  McMurry  et al → Crusher #6; 2004-11-23 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** McMurry Ready Mix → Crusher #6; 2010-06-14 to 2020-12-15; source msha-controller-operator-history
- **controller_controls_operator:** Ron  McMurry  et al → McMurry Ready Mix; 2010-06-14 to 2020-12-15; source msha-controller-operator-history
- **operator_operates_mine:** JTL GROUP,INC. → Crusher #6; 2020-12-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → JTL GROUP,INC.; 2020-12-16 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Crusher #6; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → JTL GROUP,INC.; 2023-06-01 to current/open; source msha-controller-operator-history