# Relationship history for MSHA mine 2103119

Current hierarchy: **MDU Resources Group Inc → Granite City Ready-Mix Inc → CRUSHING UNIT 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:** Robert C  Bogard Jr → CRUSHING UNIT 1; 1950-01-01 to 2003-03-12; source msha-controller-operator-history
- **operator_operates_mine:** Granite City Ready-Mix Inc → CRUSHING UNIT 1; 1996-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert C  Bogard Jr → Granite City Ready-Mix Inc; 1996-05-01 to 2003-03-12; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → CRUSHING UNIT 1; 2003-03-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Granite City Ready-Mix Inc; 2003-03-13 to current/open; source msha-controller-operator-history