# Relationship history for MSHA mine 4703141

Current hierarchy: **Kurt  French → Knitt Sand & Gravel Inc → PORTABLE PIONEER 356**

- 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:** Kurt  French → PORTABLE PIONEER 356; 1988-09-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Knitt Sand & Gravel Inc → PORTABLE PIONEER 356; 1998-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Kurt  French → Knitt Sand & Gravel Inc; 1998-05-01 to current/open; source msha-controller-operator-history