# Relationship history for MSHA mine 0102570

Current hierarchy: **Hurst Thomas H → B W S Technology Inc → West Blocton #1**

- 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

- **controller_controls_mine:** Powell Joe E → West Blocton #1; 1983-07-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Pickens Coal Inc → West Blocton #1; 1984-02-01 to 1988-10-10; source msha-controller-operator-history
- **controller_controls_operator:** Powell Joe E → Pickens Coal Inc; 1984-02-01 to 1988-10-10; source msha-controller-operator-history
- **operator_operates_mine:** B W S Technology Inc → West Blocton #1; 1988-10-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Hurst Thomas H → West Blocton #1; 1988-10-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hurst Thomas H → B W S Technology Inc; 1988-10-11 to current/open; source msha-controller-operator-history