# Relationship history for MSHA mine 3901421

Current hierarchy: **Roth Jennifer → High Plains Materials Inc → PORTEC PLANT**

- 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:** High Plains Materials Inc → PORTEC PLANT; 1998-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Roth Jennifer → PORTEC PLANT; 1998-04-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Roth Jennifer → High Plains Materials Inc; 1998-04-01 to current/open; source msha-controller-operator-history