# Relationship history for MSHA mine 2402486

Current hierarchy: **Archie J  Knerr → Thompson Falls Sand and Gravel → Crusher**

- 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:** Archie J  Knerr → Crusher; 1997-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Thompson Falls Sand and Gravel → Crusher; 2007-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Archie J  Knerr → Thompson Falls Sand and Gravel; 2007-07-10 to current/open; source msha-controller-operator-history