# Relationship history for MSHA mine 1600919

Current hierarchy: **Texas Industries Inc → Louisiana Industries → Harvell Dredge & 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

- **controller_controls_mine:** Texas Industries Inc → Harvell Dredge & Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Louisiana Sand & Gravel Co Of Baton Rouge Inc → Harvell Dredge & Plant; 1950-01-01 to 1985-10-02; source msha-controller-operator-history
- **controller_controls_mine:** Herbert S  Verbois → Harvell Dredge & Plant; 1950-01-01 to 1985-10-02; source msha-controller-operator-history
- **controller_controls_operator:** Herbert S  Verbois → Louisiana Sand & Gravel Co Of Baton Rouge Inc; 1950-01-01 to 1985-10-02; source msha-controller-operator-history
- **operator_operates_mine:** Louisiana Industries → Harvell Dredge & Plant; 1985-10-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Texas Industries Inc → Louisiana Industries; 1985-10-03 to current/open; source msha-controller-operator-history