# Relationship history for MSHA mine 3503402

Current hierarchy: **MDU Resources Group Inc → Rogue Aggregates Inc. → Quality Rock Pit**

- 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 → Quality Rock Pit; 1993-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Quality Rock Products Inc → Quality Rock Pit; 1993-12-01 to 2001-08-16; source msha-controller-operator-history
- **controller_controls_mine:** George A  Harshman → Quality Rock Pit; 1993-12-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** George A  Harshman → Quality Rock Products Inc; 1993-12-01 to 2001-08-16; source msha-controller-operator-history
- **operator_operates_mine:** Rogue Aggregates Inc. → Quality Rock Pit; 2001-08-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Rogue Aggregates Inc.; 2001-08-17 to current/open; source msha-controller-operator-history