# Relationship history for MSHA mine 2102936

Current hierarchy: **Knife River Corporation → Knife River Corporation North Central → 513325**

- 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:** Bauerly Brothers Inc → 513325; 1950-01-01 to 2001-04-25; source msha-controller-operator-history
- **controller_controls_mine:** Daniel J  Surma et al → 513325; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tri-City Paving, Inc. → 513325; 1985-05-01 to 2018-06-24; source msha-controller-operator-history
- **controller_controls_operator:** Daniel J  Surma et al → Tri-City Paving, Inc.; 1985-05-01 to 2018-06-24; source msha-controller-operator-history
- **controller_controls_operator:** John D  Surma et al → Tri-City Paving, Inc.; 1985-05-01 to 2018-06-24; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → 513325; 2001-04-26 to 2023-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Knife River Corporation North Central → 513325; 2018-06-25 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bauerly Brothers Inc → Knife River Corporation North Central; 2018-06-25 to 2001-04-25; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Knife River Corporation North Central; 2018-06-25 to 2023-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Knife River Corporation → 513325; 2023-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Knife River Corporation → Knife River Corporation North Central; 2023-06-01 to current/open; source msha-controller-operator-history