# Relationship history for MSHA mine 0405566

Current hierarchy: **Vernon L Shepherd; Ray E Bluff → Penon Blanco Mineral Resources → Penon Blanco Mine**

- 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:** Penon Blanco Mineral Resources → Penon Blanco Mine; 2003-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Vernon L Shepherd et al → Penon Blanco Mine; 2003-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Vernon L Shepherd et al → Penon Blanco Mineral Resources; 2003-05-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Ray E Bluff et al → Penon Blanco Mineral Resources; 2003-05-14 to current/open; source msha-controller-operator-history