# Relationship history for MSHA mine 3304801

Current hierarchy: **CRH PLC → Shelly Materials, Inc. → Southern Portable 1**

- 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:** CRH PLC → Southern Portable 1; 2000-03-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Shelly Materials, Inc. → Southern Portable 1; 2023-11-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** CRH PLC → Shelly Materials, Inc.; 2023-11-03 to current/open; source msha-controller-operator-history