# Relationship history for MSHA mine 3101905

Current hierarchy: **Robert Patrick  Spangler → Burns & Spangler Inc → 221 Road Job**

- 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:** Robert Patrick  Spangler → 221 Road Job; 1979-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Burns & Spangler Inc → 221 Road Job; 1980-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Robert Patrick  Spangler → Burns & Spangler Inc; 1980-01-01 to current/open; source msha-controller-operator-history