# Relationship history for MSHA mine 4102519

Current hierarchy: **Trinity Industries Inc → Transit Mix Concrete & Materials Company → Rainbow Rock 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Cle-Tex Materials Inc → Rainbow Rock Plant; 1950-01-01 to 1993-03-30; source msha-controller-operator-history
- **controller_controls_mine:** B Curtis  Smith → Rainbow Rock Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** B Curtis  Smith → Cle-Tex Materials Inc; 1950-01-01 to 1993-03-30; source msha-controller-operator-history
- **controller_controls_mine:** Trinity Industries Inc → Rainbow Rock Plant; 1992-12-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Transit Mix Concrete & Materials Company → Rainbow Rock Plant; 1993-03-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Trinity Industries Inc → Transit Mix Concrete & Materials Company; 1993-03-31 to current/open; source msha-controller-operator-history