# Relationship history for MSHA mine 1800573

Current hierarchy: **Martin Marietta Materials Inc → Bluegrass Materials Company, LLC → Blue Mount 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:** Bluemount Crushed Stone Inc → Blue Mount Quarry; 1950-01-01 to 1979-06-05; source msha-controller-operator-history
- **controller_controls_mine:** Le Brun Henry F → Blue Mount Quarry; 1950-01-01 to 1979-06-05; source msha-controller-operator-history
- **controller_controls_operator:** Le Brun Henry F → Bluemount Crushed Stone Inc; 1950-01-01 to 1979-06-05; source msha-controller-operator-history
- **operator_operates_mine:** Blue Mount Quarry Inc → Blue Mount Quarry; 1979-06-06 to 2007-08-19; source msha-controller-operator-history
- **controller_controls_mine:** Explosives Engineers Inc → Blue Mount Quarry; 1979-06-06 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Explosives Engineers Inc → Blue Mount Quarry Inc; 1979-06-06 to 2007-08-19; source msha-controller-operator-history
- **operator_operates_mine:** Blue Mount Materials LLC → Blue Mount Quarry; 2007-08-20 to 2015-12-13; source msha-controller-operator-history
- **controller_controls_mine:** Francis E  Gardiner III et al → Blue Mount Quarry; 2007-08-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Francis E  Gardiner III et al → Blue Mount Materials LLC; 2007-08-20 to 2015-12-13; source msha-controller-operator-history
- **controller_controls_mine:** Panadero Aggregates Holdings, LLC → Blue Mount Quarry; 2010-08-26 to 2018-04-26; source msha-controller-operator-history
- **operator_operates_mine:** Bluegrass Materials Company, LLC → Blue Mount Quarry; 2015-12-14 to 2015-12-14; source msha-controller-operator-history
- **controller_controls_operator:** Panadero Aggregates Holdings, LLC → Bluegrass Materials Company, LLC; 2015-12-14 to 2015-12-14; source msha-controller-operator-history
- **operator_operates_mine:** Bluegrass - Blue Mount Materials, LLC → Blue Mount Quarry; 2015-12-15 to 2018-04-26; source msha-controller-operator-history
- **controller_controls_mine:** Panadero Aggregates Holdings, LLC → Blue Mount Quarry; 2015-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Panadero Aggregates Holdings, LLC → Bluegrass - Blue Mount Materials, LLC; 2015-12-15 to 2018-04-26; source msha-controller-operator-history
- **operator_operates_mine:** Bluegrass Materials Company, LLC → Blue Mount Quarry; 2018-04-27 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Panadero Aggregates Holdings, LLC → Bluegrass Materials Company, LLC; 2018-04-27 to 2018-04-26; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Blue Mount 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 2015-12-14; 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