# Relationship history for MSHA mine 4202675

Current hierarchy: **Knife River Corporation → Knife River → Grantsville Pit**

- 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:** Knife River → Grantsville Pit; 2017-08-07 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Thom  Morgan → Grantsville Pit; 2017-08-07 to 2026-02-26; source msha-controller-operator-history
- **controller_controls_operator:** Thom  Morgan → Knife River; 2017-08-07 to 2026-02-26; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Grantsville Pit; 2026-02-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Knife River; 2026-02-27 to current/open; source msha-controller-operator-history