# Relationship history for MSHA mine 3800141

Current hierarchy: **Tony  Rucker → R&T Grading, Inc → FRICK MINE**

- 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:** Wilson Brothers Sand Company Inc → FRICK MINE; 1950-01-01 to 2007-10-15; source msha-controller-operator-history
- **controller_controls_mine:** Thomas W  Wilson → FRICK MINE; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Thomas W  Wilson → Wilson Brothers Sand Company Inc; 1950-01-01 to 2007-10-15; source msha-controller-operator-history
- **operator_operates_mine:** Wilson Sand Company, LLC → FRICK MINE; 2007-10-16 to 2021-10-31; source msha-controller-operator-history
- **controller_controls_mine:** Yvonne W  Rouse → FRICK MINE; 2007-10-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Yvonne W  Rouse → Wilson Sand Company, LLC; 2007-10-16 to 2021-10-31; source msha-controller-operator-history
- **operator_operates_mine:** R&T Grading, Inc → FRICK MINE; 2021-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Tony  Rucker → FRICK MINE; 2021-11-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Tony  Rucker → R&T Grading, Inc; 2021-11-01 to current/open; source msha-controller-operator-history