# Relationship history for MSHA mine 0901126

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → Morgan County 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

- **controller_controls_mine:** Martin Marietta Materials Inc → Morgan County Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Blue Circle Industries Plc → Morgan County Quarry; 1987-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Blue Circle Aggregates Inc → Morgan County Quarry; 1999-10-01 to 2001-07-11; source msha-controller-operator-history
- **controller_controls_operator:** Blue Circle Industries Plc → Blue Circle Aggregates Inc; 1999-10-01 to 2001-07-11; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Morgan County Quarry; 2001-07-12 to 2015-07-09; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Aggregates Southeast → Morgan County Quarry; 2001-07-12 to 2010-12-31; source msha-controller-operator-history
- **controller_controls_mine:** Lafarge S A → Morgan County Quarry; 2001-07-12 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Aggregates Southeast; 2001-07-12 to 2010-12-31; source msha-controller-operator-history
- **operator_operates_mine:** Lafarge Building Materials → Morgan County Quarry; 2011-01-01 to 2013-06-30; source msha-controller-operator-history
- **controller_controls_operator:** Lafarge S A → Lafarge Building Materials; 2011-01-01 to 2013-06-30; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → Morgan County Quarry; 2013-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2013-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Holcim Ltd → Morgan County Quarry; 2015-07-10 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Holcim Ltd → Lafarge Building Materials; 2015-07-10 to 2013-06-30; source msha-controller-operator-history