# Relationship history for MSHA mine 3800575

Current hierarchy: **Quikrete Holdings Inc. → American Materials Company LLC → Sumter Sand**

- 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:** Sumter County Sand → Sumter Sand; 1980-10-01 to 2017-05-14; source msha-controller-operator-history
- **controller_controls_mine:** James (Tommy)  Glasscock → Sumter Sand; 1980-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James (Tommy)  Glasscock → Sumter County Sand; 1980-10-01 to 2017-05-14; source msha-controller-operator-history
- **controller_controls_mine:** Gary (Tim)  Bizzell  et al → Sumter Sand; 1999-11-02 to 2016-02-04; source msha-controller-operator-history
- **controller_controls_mine:** Summit Materials LLC → Sumter Sand; 2016-02-05 to 2025-08-03; source msha-controller-operator-history
- **operator_operates_mine:** American Materials Company LLC → Sumter Sand; 2017-05-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Summit Materials LLC → American Materials Company LLC; 2017-05-15 to 2025-08-03; source msha-controller-operator-history
- **controller_controls_operator:** Gary (Tim)  Bizzell  et al → American Materials Company LLC; 2017-05-15 to 2016-02-04; source msha-controller-operator-history
- **controller_controls_mine:** Quikrete Holdings Inc. → Sumter Sand; 2025-08-04 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Quikrete Holdings Inc. → American Materials Company LLC; 2025-08-04 to current/open; source msha-controller-operator-history