# Relationship history for MSHA mine 4103793

Current hierarchy: **Lafarge Corp; Pioneer International Ltd → Chico Crushed Stone Partnership → Portable Chico Plant #34**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Lafarge Corp et al → Portable Chico Plant #34; 1989-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Chico Crushed Stone Partnership → Portable Chico Plant #34; 1993-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge Corp et al → Chico Crushed Stone Partnership; 1993-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pioneer International Ltd  et al → Chico Crushed Stone Partnership; 1993-09-01 to current/open; source msha-controller-operator-history