# Relationship history for MSHA mine 3503401

Current hierarchy: **Knife River Corporation → Morse Brothers Inc → SUNDIAL**

- 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:** Roger  Ekstrom → SUNDIAL; 1950-01-01 to 2000-05-21; source msha-controller-operator-history
- **operator_operates_mine:** Gresham Sand & Gravel Company → SUNDIAL; 1993-11-01 to 2000-05-21; source msha-controller-operator-history
- **controller_controls_operator:** Roger  Ekstrom → Gresham Sand & Gravel Company; 1993-11-01 to 2000-05-21; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → SUNDIAL; 1998-03-05 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Morse Brothers Inc → SUNDIAL; 2000-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Morse Brothers Inc; 2000-05-22 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → SUNDIAL; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Morse Brothers Inc; 2023-06-01 to current/open; source msha-controller-operator-history