# Relationship history for MSHA mine 2402121

Current hierarchy: **Levi Jay  Thompson → Thompson River Ready Mix Inc. → Thompson River Ready Mix Inc.**

- 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

- **operator_operates_mine:** Thompson Falls Sand & Gravel → Thompson River Ready Mix Inc.; 1997-09-01 to 2024-01-14; source msha-controller-operator-history
- **controller_controls_mine:** Archie J  Knerr → Thompson River Ready Mix Inc.; 1997-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Archie J  Knerr → Thompson Falls Sand & Gravel; 1997-09-01 to 2024-01-14; source msha-controller-operator-history
- **operator_operates_mine:** Thompson River Ready Mix Inc. → Thompson River Ready Mix Inc.; 2024-01-15 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Levi Jay  Thompson → Thompson River Ready Mix Inc.; 2024-01-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Levi Jay  Thompson → Thompson River Ready Mix Inc.; 2024-01-15 to current/open; source msha-controller-operator-history