# Relationship history for MSHA mine 0405870

Current hierarchy: **Heidelberg Materials AG → Lehigh Southwest Cement Company → Permanente Rock Plant**

- 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

- **controller_controls_mine:** Heidelberg Materials AG → Permanente Rock Plant; 1999-05-12 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lehigh Southwest Cement Company → Permanente Rock Plant; 2013-04-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidelberg Materials AG → Lehigh Southwest Cement Company; 2013-04-30 to current/open; source msha-controller-operator-history