# Relationship history for MSHA mine 4101472

Current hierarchy: **Robert Glenn  McClain; Gregory  Angel; Shawn L  Barnes; Gary  Angel → MineralTech Gulf Coast Abrasives, LLC → Deweyville 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:** Specialty Sand Company Inc. → Deweyville Plant; 1950-01-01 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_mine:** W A  Keckley → Deweyville Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** W A  Keckley → Specialty Sand Company Inc.; 1950-01-01 to 2022-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Gregory  Angel et al → Deweyville Plant; 2017-12-28 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** MineralTech Gulf Coast Abrasives, LLC → Deweyville Plant; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregory  Angel et al → MineralTech Gulf Coast Abrasives, LLC; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert Glenn  McClain et al → MineralTech Gulf Coast Abrasives, LLC; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shawn L  Barnes et al → MineralTech Gulf Coast Abrasives, LLC; 2023-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary  Angel et al → MineralTech Gulf Coast Abrasives, LLC; 2023-01-01 to current/open; source msha-controller-operator-history