# Relationship history for MSHA mine 3503371

Current hierarchy: **Cemex S A → Walling Sand & Gravel Company → TURNER SITE - PLANT 4**

- 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

- **controller_controls_mine:** Jerry H  Walling → TURNER SITE - PLANT 4; 1950-01-01 to 2007-04-23; source msha-controller-operator-history
- **operator_operates_mine:** Walling Sand & Gravel Company → TURNER SITE - PLANT 4; 1992-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jerry H  Walling → Walling Sand & Gravel Company; 1992-05-01 to 2007-04-23; source msha-controller-operator-history
- **controller_controls_mine:** Rinker Group Ltd → TURNER SITE - PLANT 4; 2007-04-24 to 2007-07-09; source msha-controller-operator-history
- **controller_controls_operator:** Rinker Group Ltd → Walling Sand & Gravel Company; 2007-04-24 to 2007-07-09; source msha-controller-operator-history
- **controller_controls_mine:** Cemex S A → TURNER SITE - PLANT 4; 2007-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → Walling Sand & Gravel Company; 2007-07-10 to current/open; source msha-controller-operator-history