# Relationship history for MSHA mine 3304546

Current hierarchy: **James P  Jurgensen II; Jacqueline J  Alf; Jason R  Jurgensen → Melvin Stone Company, LLC → Clinton County 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:** Martin Marietta Materials Inc → Clinton County Plant; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** James P  Jurgensen → Clinton County Plant; 1999-08-06 to 2018-04-30; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials → Clinton County Plant; 2006-02-01 to 2016-06-01; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials; 2006-02-01 to 2016-06-01; source msha-controller-operator-history
- **operator_operates_mine:** Melvin Stone Company, LLC → Clinton County Plant; 2016-06-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James P  Jurgensen → Melvin Stone Company, LLC; 2016-06-02 to 2018-04-30; source msha-controller-operator-history
- **controller_controls_mine:** Jason R  Jurgensen et al → Clinton County Plant; 2018-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jason R  Jurgensen et al → Melvin Stone Company, LLC; 2018-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jacqueline J  Alf et al → Melvin Stone Company, LLC; 2018-05-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** James P  Jurgensen II et al → Melvin Stone Company, LLC; 2018-05-01 to current/open; source msha-controller-operator-history