# Relationship history for MSHA mine 4503496

Current hierarchy: **Terry L  Schmid → Terry Schmid Gravel → Terry Schmid Gravel/Pit #1**

- 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:** Terry Schmid Gravel → Terry Schmid Gravel/Pit #1; 2001-08-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Terry L  Schmid → Terry Schmid Gravel/Pit #1; 2001-08-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Terry L  Schmid → Terry Schmid Gravel; 2001-08-27 to current/open; source msha-controller-operator-history