# Relationship history for MSHA mine 3503648

Current hierarchy: **Knife River Corporation → Knife River Corporation- Northwest → Lamonta**

- 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 → Lamonta; 1998-03-05 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** ROCK PRODUCTS MFG INC → Lamonta; 2006-07-24 to 2024-10-18; source msha-controller-operator-history
- **controller_controls_mine:** Mark  Stafford → Lamonta; 2006-07-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Mark  Stafford → ROCK PRODUCTS MFG INC; 2006-07-24 to 2024-10-18; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → Lamonta; 2023-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Knife River Corporation- Northwest → Lamonta; 2024-10-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Knife River Corporation- Northwest; 2024-10-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Knife River Corporation- Northwest; 2024-10-19 to 2023-05-31; source msha-controller-operator-history