# Relationship history for MSHA mine 4101242

Current hierarchy: **Lafarge Corp; Pioneer International Ltd → Chico Crushed Stone Partnership → Chico Plant #32**

- 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:** Chico Crushed Stone Inc → Chico Plant #32; 1950-01-01 to 1988-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Van C  Cox → Chico Plant #32; 1950-01-01 to 1988-05-31; source msha-controller-operator-history
- **controller_controls_operator:** Van C  Cox → Chico Crushed Stone Inc; 1950-01-01 to 1988-05-31; source msha-controller-operator-history
- **operator_operates_mine:** Chico Crushed Stone Inc → Chico Plant #32; 1988-06-01 to 1989-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Tarmac Plc → Chico Plant #32; 1988-06-01 to 1989-08-31; source msha-controller-operator-history
- **controller_controls_operator:** Tarmac Plc → Chico Crushed Stone Inc; 1988-06-01 to 1989-08-31; source msha-controller-operator-history
- **operator_operates_mine:** Chico Crushed Stone Partnership → Chico Plant #32; 1989-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Pioneer International Ltd  et al → Chico Plant #32; 1989-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Pioneer International Ltd  et al → Chico Crushed Stone Partnership; 1989-09-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge Corp et al → Chico Crushed Stone Partnership; 1989-09-01 to current/open; source msha-controller-operator-history