# Relationship history for MSHA mine 4503801

Current hierarchy: **Izak  Riley → IV Riley Materials, Inc. → 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** IV Riley Materials, Inc. → Portable 1; 2020-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Izak  Riley → Portable 1; 2020-05-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Izak  Riley → IV Riley Materials, Inc.; 2020-05-22 to current/open; source msha-controller-operator-history