# Relationship history for MSHA mine 0401800

Current hierarchy: **Vulcan Materials Company → CalMat Co → San Emidio Plant**

- 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

- **operator_operates_mine:** Bakersfield Ready Mix Inc → San Emidio Plant; 1950-01-01 to 1985-07-31; source msha-controller-operator-history
- **controller_controls_mine:** Rayburn S  Dezember → San Emidio Plant; 1950-01-01 to 1985-07-31; source msha-controller-operator-history
- **controller_controls_operator:** Rayburn S  Dezember → Bakersfield Ready Mix Inc; 1950-01-01 to 1985-07-31; source msha-controller-operator-history
- **operator_operates_mine:** Calmat Of Central California → San Emidio Plant; 1985-08-01 to 1999-01-05; source msha-controller-operator-history
- **controller_controls_mine:** Calmat Company → San Emidio Plant; 1985-08-01 to 1999-01-05; source msha-controller-operator-history
- **controller_controls_operator:** Calmat Company → Calmat Of Central California; 1985-08-01 to 1999-01-05; source msha-controller-operator-history
- **operator_operates_mine:** CalMat Co → San Emidio Plant; 1999-01-06 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → San Emidio Plant; 1999-01-06 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_operator:** Legacy Vulcan Corp (Form:Vulcan Materials Co) → CalMat Co; 1999-01-06 to 2007-11-15; source msha-controller-operator-history
- **controller_controls_mine:** Vulcan Materials Company → San Emidio Plant; 2007-11-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vulcan Materials Company → CalMat Co; 2007-11-16 to current/open; source msha-controller-operator-history