# Relationship history for MSHA mine 3301676

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials, Inc. → Apple Grove**

- 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 → Apple Grove; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Dravo Basic Materials Company Inc → Apple Grove; 1950-01-01 to 1995-01-02; source msha-controller-operator-history
- **controller_controls_mine:** Dravo Corp → Apple Grove; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Dravo Corp → Dravo Basic Materials Company Inc; 1950-01-01 to 1995-01-02; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Aggregates → Apple Grove; 1995-01-03 to 2005-05-18; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Aggregates; 1995-01-03 to 2005-05-18; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials, Inc. → Apple Grove; 2005-05-19 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials, Inc.; 2005-05-19 to current/open; source msha-controller-operator-history