# Relationship history for MSHA mine 3608365

Current hierarchy: **Patterson Tom Jr → Tom Patterson Coal Company → Robert Sperko Strip**

- 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:** Patterson Tom Jr → Robert Sperko Strip; 1982-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Tom Patterson Coal Company → Robert Sperko Strip; 1992-10-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patterson Tom Jr → Tom Patterson Coal Company; 1992-10-01 to current/open; source msha-controller-operator-history