# Relationship history for MSHA mine 1800525

Current hierarchy: **Tri-Star Soil Inc → Tri-Star Soil Inc → Superior Sand Company**

- 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:** Superior Sand Company-Div/General Paving Co → Superior Sand Company; 1950-01-01 to 1992-10-23; source msha-controller-operator-history
- **controller_controls_mine:** General Paving Company → Superior Sand Company; 1950-01-01 to 1992-10-23; source msha-controller-operator-history
- **controller_controls_operator:** General Paving Company → Superior Sand Company-Div/General Paving Co; 1950-01-01 to 1992-10-23; source msha-controller-operator-history
- **operator_operates_mine:** Tri-Star Soil Inc → Superior Sand Company; 1992-10-24 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tri-Star Soil Inc → Superior Sand Company; 1992-10-24 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tri-Star Soil Inc → Tri-Star Soil Inc; 1992-10-24 to current/open; source msha-controller-operator-history