# Relationship history for MSHA mine 3003832

Current hierarchy: **Hannah L  Robinson → H L Robinson Sand & Gravel → Extec Screening Plant Serial # 10144**

- 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:** Hannah L  Robinson → Extec Screening Plant Serial # 10144; 1988-08-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** H L Robinson Sand & Gravel → Extec Screening Plant Serial # 10144; 2012-06-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Hannah L  Robinson → H L Robinson Sand & Gravel; 2012-06-19 to current/open; source msha-controller-operator-history