# Relationship history for MSHA mine 1600337

Current hierarchy: **Rapides Gravel Co; L H  Bossier → Mid State Materials Inc → Mid State Materials Incorporated**

- 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

- **operator_operates_mine:** Mid State Materials Inc → Mid State Materials Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** L H  Bossier  et al → Mid State Materials Incorporated; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** L H  Bossier  et al → Mid State Materials Inc; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rapides Gravel Co  et al → Mid State Materials Inc; 1950-01-01 to current/open; source msha-controller-operator-history