# Relationship history for MSHA mine 4104380

Current hierarchy: **Martin Marietta Materials Inc → Martin Marietta Materials Southwest LLC → North Austin 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:** American Aggregates → North Austin Quarry; 2002-08-13 to 2013-04-01; source msha-controller-operator-history
- **controller_controls_mine:** Blake A  Kuhlman → North Austin Quarry; 2002-08-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Blake A  Kuhlman → American Aggregates; 2002-08-13 to 2013-04-01; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → North Austin Quarry; 2007-11-26 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Texas Limestone Materials, LLC → North Austin Quarry; 2013-04-02 to 2015-08-16; source msha-controller-operator-history
- **controller_controls_mine:** Group Investment Holdings Inc → North Austin Quarry; 2013-04-02 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Group Investment Holdings Inc → Texas Limestone Materials, LLC; 2013-04-02 to 2015-08-16; source msha-controller-operator-history
- **operator_operates_mine:** CC Aggregates LLC → North Austin Quarry; 2015-08-17 to 2021-10-21; source msha-controller-operator-history
- **controller_controls_mine:** Curtis L  Griffin → North Austin Quarry; 2015-08-17 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Curtis L  Griffin → CC Aggregates LLC; 2015-08-17 to 2021-10-21; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Southwest LLC → North Austin Quarry; 2021-10-22 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Southwest LLC; 2021-10-22 to current/open; source msha-controller-operator-history