# Relationship history for MSHA mine 3603551

Current hierarchy: **Louis J  Beltrami → Beltrami Enterprises Inc → Harwood Cleaning 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: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **controller_controls_mine:** Louis J  Beltrami → Harwood Cleaning Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Brook Contracting Corp → Harwood Cleaning Plant; 1950-01-01 to 1974-08-01; source msha-controller-operator-history
- **controller_controls_mine:** US Anthracite Corp → Harwood Cleaning Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** US Anthracite Corp → Brook Contracting Corp; 1950-01-01 to 1974-08-01; source msha-controller-operator-history
- **operator_operates_mine:** Beltrami Enterprises Inc → Harwood Cleaning Plant; 1974-08-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Louis J  Beltrami → Beltrami Enterprises Inc; 1974-08-02 to current/open; source msha-controller-operator-history