# Relationship history for MSHA mine 0801083

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → Perry 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 → Perry Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Dravo Corp → Perry Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dravo Basic Materials Company Inc → Perry Quarry; 1987-10-01 to 1995-01-02; source msha-controller-operator-history
- **controller_controls_operator:** Dravo Corp → Dravo Basic Materials Company Inc; 1987-10-01 to 1995-01-02; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → Perry Quarry; 1995-01-03 to 2005-07-13; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1995-01-03 to 2005-07-13; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → Perry Quarry; 2005-07-14 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2005-07-14 to current/open; source msha-controller-operator-history