# Relationship history for MSHA mine 1517075

Current hierarchy: **Rogers Group Inc → Rogers Group Inc. → Princeton Specialty Products**

- 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

- **controller_controls_mine:** Rogers Group Inc → Princeton Specialty Products; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Specialty Rock Products Inc → Princeton Specialty Products; 1991-05-01 to 2012-11-25; source msha-controller-operator-history
- **controller_controls_mine:** Barry  Howton → Princeton Specialty Products; 1991-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Barry  Howton → Specialty Rock Products Inc; 1991-05-01 to 2012-11-25; source msha-controller-operator-history
- **operator_operates_mine:** Rogers Group Inc. → Princeton Specialty Products; 2012-11-26 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Rogers Group Inc → Rogers Group Inc.; 2012-11-26 to current/open; source msha-controller-operator-history