# Relationship history for MSHA mine 3503469

Current hierarchy: **MDU Resources Group Inc → Rogue Aggregates Inc → WHETSTONE**

- 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:** Jim  Salyer → WHETSTONE; 1993-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** MDU Resources Group Inc → WHETSTONE; 1993-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Southern Oregon Underground → WHETSTONE; 1998-09-01 to 1999-05-19; source msha-controller-operator-history
- **controller_controls_operator:** Jim  Salyer → Southern Oregon Underground; 1998-09-01 to 1999-05-19; source msha-controller-operator-history
- **operator_operates_mine:** Rogue Aggregates Inc → WHETSTONE; 1999-05-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MDU Resources Group Inc → Rogue Aggregates Inc; 1999-05-20 to current/open; source msha-controller-operator-history