# Relationship history for MSHA mine 2003197

Current hierarchy: **Andrew J.  Zylstra → A.T. Zylstra, LLC → Flat River Gravel**

- 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:** Dana Sweet & Sons Inc. → Flat River Gravel; 2001-04-01 to 2023-06-21; source msha-controller-operator-history
- **controller_controls_mine:** Dana  Sweet → Flat River Gravel; 2001-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dana  Sweet → Dana Sweet & Sons Inc.; 2001-04-01 to 2023-06-21; source msha-controller-operator-history
- **operator_operates_mine:** A.T. Zylstra, LLC → Flat River Gravel; 2023-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Andrew J.  Zylstra → Flat River Gravel; 2023-06-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Andrew J.  Zylstra → A.T. Zylstra, LLC; 2023-06-22 to current/open; source msha-controller-operator-history