# Relationship history for MSHA mine 2003300

Current hierarchy: **Joe  Riccardi → Northern Material Co., Inc. → Northern Materials Co., Inc.**

- 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:** Northern Material Co., Inc. → Northern Materials Co., Inc.; 2004-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Joe  Riccardi → Northern Materials Co., Inc.; 2004-07-29 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joe  Riccardi → Northern Material Co., Inc.; 2004-07-29 to current/open; source msha-controller-operator-history