# Relationship history for MSHA mine 0401704

Current hierarchy: **Knife River Corporation → Baldwin Contracting Company Inc → Doyle 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

- **controller_controls_mine:** M & T Inc → Doyle Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Basic Rock Products Inc → Doyle Pit; 1950-01-01 to 1979-12-04; source msha-controller-operator-history
- **controller_controls_mine:** Hammond William O → Doyle Pit; 1950-01-01 to 1979-12-04; source msha-controller-operator-history
- **controller_controls_operator:** Hammond William O → Basic Rock Products Inc; 1950-01-01 to 1979-12-04; source msha-controller-operator-history
- **operator_operates_mine:** Baldwin Contracting Company Inc → Doyle Pit; 1979-12-05 to 1999-02-08; source msha-controller-operator-history
- **controller_controls_operator:** M & T Inc → Baldwin Contracting Company Inc; 1979-12-05 to 1999-02-08; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → Doyle Pit; 1996-08-01 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Baldwin Contracting Company Inc → Doyle Pit; 1999-02-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Baldwin Contracting Company Inc; 1999-02-09 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Doyle Pit; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Baldwin Contracting Company Inc; 2023-06-01 to current/open; source msha-controller-operator-history