# Relationship history for MSHA mine 3503558

Current hierarchy: **Knife River Corporation → Knife River Corporation-Northwest → METRO PORTABLE #1**

- 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:** MDU Resources Group Inc → METRO PORTABLE #1; 1998-03-05 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** David M  Larson → METRO PORTABLE #1; 1998-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Larson Construction Co., Inc. → METRO PORTABLE #1; 2002-05-10 to 2003-07-15; source msha-controller-operator-history
- **controller_controls_operator:** David M  Larson → Larson Construction Co., Inc.; 2002-05-10 to 2003-07-15; source msha-controller-operator-history
- **operator_operates_mine:** H. E. Johnson & Sons Const. Co. Inc. → METRO PORTABLE #1; 2003-07-16 to 2006-09-24; source msha-controller-operator-history
- **controller_controls_mine:** David M  Larson → METRO PORTABLE #1; 2003-07-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David M  Larson → H. E. Johnson & Sons Const. Co. Inc.; 2003-07-16 to 2006-09-24; source msha-controller-operator-history
- **operator_operates_mine:** Teevin & Fischer Quarry LLC → METRO PORTABLE #1; 2006-09-25 to 2018-05-06; source msha-controller-operator-history
- **controller_controls_mine:** Shawn  Teevin et al → METRO PORTABLE #1; 2006-09-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shawn  Teevin et al → Teevin & Fischer Quarry LLC; 2006-09-25 to 2018-05-06; source msha-controller-operator-history
- **controller_controls_operator:** Tom  Fischer et al → Teevin & Fischer Quarry LLC; 2006-09-25 to 2018-05-06; source msha-controller-operator-history
- **operator_operates_mine:** Knife River Corporation-Northwest → METRO PORTABLE #1; 2018-05-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Knife River Corporation-Northwest; 2018-05-07 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → METRO PORTABLE #1; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Knife River Corporation-Northwest; 2023-06-01 to current/open; source msha-controller-operator-history