# Relationship history for MSHA mine 4503692

Current hierarchy: **Heidelberg Materials AG → Cadman Materials Inc. → Portable #2**

- 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:** Cemex S A → Portable #2; 2008-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** CEMEX Construction Materials Pacific, LLC → Portable #2; 2011-08-16 to 2017-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Cemex S A → CEMEX Construction Materials Pacific, LLC; 2011-08-16 to 2017-06-30; source msha-controller-operator-history
- **controller_controls_mine:** Heidelberg Materials AG → Portable #2; 2017-06-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Cadman Materials Inc. → Portable #2; 2017-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Cadman Materials Inc.; 2017-07-01 to current/open; source msha-controller-operator-history