# Relationship history for MSHA mine 2902232

Current hierarchy: **Lafarge S A → Lafarge West Inc → Chiefton Powerscreen**

- 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:** Lafarge S A → Chiefton Powerscreen; 2002-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Southwest → Chiefton Powerscreen; 2002-01-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Southwest; 2002-01-15 to current/open; source msha-controller-operator-history