# Relationship history for MSHA mine 1600805

Current hierarchy: **White Jim → White Sand & Gravel → White Sand & 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** La-37 Sand & Gravel Inc → White Sand & Gravel; 1950-01-01 to 1981-11-11; source msha-controller-operator-history
- **controller_controls_mine:** Womack Dale → White Sand & Gravel; 1950-01-01 to 1981-11-11; source msha-controller-operator-history
- **controller_controls_operator:** Womack Dale → La-37 Sand & Gravel Inc; 1950-01-01 to 1981-11-11; source msha-controller-operator-history
- **operator_operates_mine:** White Sand & Gravel → White Sand & Gravel; 1981-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** White Jim → White Sand & Gravel; 1981-11-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** White Jim → White Sand & Gravel; 1981-11-12 to current/open; source msha-controller-operator-history