# Relationship history for MSHA mine 3600168

Current hierarchy: **Martin Marietta Materials Inc → Bluegrass Materials Company, LLC → Warfordsburg Quarry**

- 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

- **operator_operates_mine:** H B Mellott Estate Inc → Warfordsburg Quarry; 1950-01-01 to 2007-08-31; source msha-controller-operator-history
- **controller_controls_mine:** H B Mellott Estate Inc → Warfordsburg Quarry; 1950-01-01 to 2022-04-04; source msha-controller-operator-history
- **controller_controls_operator:** H B Mellott Estate Inc → H B Mellott Estate Inc; 1950-01-01 to 2007-08-31; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Warfordsburg Quarry; 1998-02-11 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Mid Atlantic, Inc. → Warfordsburg Quarry; 2007-09-01 to 2009-10-05; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Mid Atlantic, Inc.; 2007-09-01 to 2009-10-05; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Warfordsburg Quarry; 2009-04-30 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Mid Atlantic, LLC → Warfordsburg Quarry; 2009-10-06 to 2014-02-12; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Mid Atlantic, LLC; 2009-10-06 to 2014-02-12; source msha-controller-operator-history
- **controller_controls_mine:** Panadero Aggregates Holdings, LLC → Warfordsburg Quarry; 2010-08-26 to 2018-04-26; source msha-controller-operator-history
- **operator_operates_mine:** Bluegrass Materials Company, LLC → Warfordsburg Quarry; 2014-02-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Panadero Aggregates Holdings, LLC → Bluegrass Materials Company, LLC; 2014-02-13 to 2018-04-26; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Warfordsburg Quarry; 2018-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Bluegrass Materials Company, LLC; 2018-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jonathan  Schilowitz → Warfordsburg Quarry; 2022-04-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jonathan  Schilowitz → H B Mellott Estate Inc; 2022-04-05 to 2007-08-31; source msha-controller-operator-history