# Relationship history for MSHA mine 3800663

Current hierarchy: **Jason C  Deck → Ameri-Con Materials Inc. → Blacksburg Plt**

- 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:** Gary K  Thomas → Blacksburg Plt; 1950-01-01 to 2016-08-17; source msha-controller-operator-history
- **operator_operates_mine:** Thomas Sand Company, Inc. → Blacksburg Plt; 1993-03-01 to 2021-01-13; source msha-controller-operator-history
- **controller_controls_operator:** Gary K  Thomas → Thomas Sand Company, Inc.; 1993-03-01 to 2016-08-17; source msha-controller-operator-history
- **controller_controls_mine:** Jason C  Deck → Blacksburg Plt; 2013-06-30 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jack E  Thomas → Blacksburg Plt; 2016-08-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jack E  Thomas → Thomas Sand Company, Inc.; 2016-08-18 to 2021-01-13; source msha-controller-operator-history
- **operator_operates_mine:** Ameri-Con Materials Inc. → Blacksburg Plt; 2021-01-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jason C  Deck → Ameri-Con Materials Inc.; 2021-01-14 to current/open; source msha-controller-operator-history