# Relationship history for MSHA mine 4103481

Current hierarchy: **Lafarge Corp; Pioneer International Ltd → Chico Crushed Stone Partnership → Plant #31**

- 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:** Chico Crushed Stone Inc → Plant #31; 1986-10-15 to 1989-09-30; source msha-controller-operator-history
- **operator_operates_mine:** Associated Crushed Stone → Plant #31; 1987-08-01 to 1989-09-30; source msha-controller-operator-history
- **controller_controls_operator:** Chico Crushed Stone Inc → Associated Crushed Stone; 1987-08-01 to 1989-09-30; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge Corp et al → Plant #31; 1989-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Chico Crushed Stone Partnership → Plant #31; 1989-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge Corp et al → Chico Crushed Stone Partnership; 1989-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pioneer International Ltd  et al → Chico Crushed Stone Partnership; 1989-10-01 to current/open; source msha-controller-operator-history