# Relationship history for MSHA mine 4103973

Current hierarchy: **Robert Glenn  McClain; Gregory  Angel; Shawn L  Barnes; Gary  Angel → MineralTech Gulf Coast Abrasives, LLC → MineralTech Gulf Coast Abrasives, LLC**

- 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:** Megasand Enterprises, Inc. → MineralTech Gulf Coast Abrasives, LLC; 1997-09-01 to 2022-07-19; source msha-controller-operator-history
- **controller_controls_mine:** Danny C  Moore  et al → MineralTech Gulf Coast Abrasives, LLC; 1997-09-01 to 2020-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Danny C  Moore  et al → Megasand Enterprises, Inc.; 1997-09-01 to 2020-03-31; source msha-controller-operator-history
- **controller_controls_operator:** Greg  Angel et al → Megasand Enterprises, Inc.; 1997-09-01 to 2020-03-31; source msha-controller-operator-history
- **controller_controls_mine:** Shawn L  Barnes et al → MineralTech Gulf Coast Abrasives, LLC; 2017-12-28 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Gary  Angel et al → MineralTech Gulf Coast Abrasives, LLC; 2020-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary  Angel et al → Megasand Enterprises, Inc.; 2020-04-01 to 2022-07-19; source msha-controller-operator-history
- **controller_controls_operator:** Greg  Angel et al → Megasand Enterprises, Inc.; 2020-04-01 to 2022-07-19; source msha-controller-operator-history
- **operator_operates_mine:** MineralTech Gulf Coast Abrasives, LLC → MineralTech Gulf Coast Abrasives, LLC; 2022-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Shawn L  Barnes et al → MineralTech Gulf Coast Abrasives, LLC; 2022-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gregory  Angel et al → MineralTech Gulf Coast Abrasives, LLC; 2022-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Gary  Angel et al → MineralTech Gulf Coast Abrasives, LLC; 2022-07-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert Glenn  McClain et al → MineralTech Gulf Coast Abrasives, LLC; 2022-07-20 to current/open; source msha-controller-operator-history