# Relationship history for MSHA mine 4503329

Current hierarchy: **CSR Ltd → Csr Associated Sand & Gravel Company Inc → PORTABLE #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:** CSR Ltd → PORTABLE #4; 1990-02-02 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Csr Associated Sand & Gravel Company Inc → PORTABLE #4; 1995-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CSR Ltd → Csr Associated Sand & Gravel Company Inc; 1995-05-01 to current/open; source msha-controller-operator-history