# Relationship history for MSHA mine 0900958

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → HOMER 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 → HOMER QUARRY; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Georgia Stone Quarries Inc → HOMER QUARRY; 1983-05-01 to 1987-11-22; source msha-controller-operator-history
- **controller_controls_mine:** Paul  Johnson → HOMER QUARRY; 1983-05-01 to 1987-11-22; source msha-controller-operator-history
- **controller_controls_operator:** Paul  Johnson → Georgia Stone Quarries Inc; 1983-05-01 to 1987-11-22; source msha-controller-operator-history
- **operator_operates_mine:** Georgia Stone Quarries Inc → HOMER QUARRY; 1987-11-23 to 1995-01-30; source msha-controller-operator-history
- **controller_controls_mine:** Richard L  Hummer et al → HOMER QUARRY; 1987-11-23 to 1995-01-30; source msha-controller-operator-history
- **controller_controls_operator:** Richard L  Hummer et al → Georgia Stone Quarries Inc; 1987-11-23 to 1995-01-30; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → HOMER QUARRY; 1995-01-31 to 2021-11-02; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1995-01-31 to 2021-11-02; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → HOMER QUARRY; 2021-11-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2021-11-03 to current/open; source msha-controller-operator-history