# Relationship history for MSHA mine 3609826

Current hierarchy: **Patrick L  Sterbutzel → T & B Excavating Inc. → T & B 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: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** T & B Excavating Inc. → T & B Strip; 2010-02-03 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Patrick L  Sterbutzel et al → T & B Strip; 2010-02-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Patrick L  Sterbutzel et al → T & B Excavating Inc.; 2010-02-03 to current/open; source msha-controller-operator-history