# Relationship history for MSHA mine 3503640

Current hierarchy: **Brian  Skidgel → Bar Seven A Companies → Portable One**

- 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:** Bar Seven A Companies → Portable One; 2006-05-16 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Brian  Skidgel → Portable One; 2006-05-16 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Brian  Skidgel → Bar Seven A Companies; 2006-05-16 to current/open; source msha-controller-operator-history